bluuebunny/crossref_metadata_2025_split huggingface dataset:
Library‐directed Solution‐ and Solid‐phase Synthesis of 2,4‐Disubstituted Pyridines: One‐pot Approach through 6 π‐Azaelectrocyclization
Authors: Sakaguchi Taku , Kobayashi Toyoharu , Hatano Sho , Tsuchikawa Hiroshi , Fukase Koichi , Tanaka Katsunori , Katsumura Shigeo 
Published: August 2009

AbstractAn efficient one‐pot synthetic procedure for the synthesis of 2,4‐disubstituted pyridines has been successfully established. The method proceeds through a 6π‐azaelectrocyclization‐aromatization sequence. Using this method, a wide variety of pyridine structures substituted at the 2‐position have been rapidly constructed from vinyl stannanes, vinyl iodide, sulfonamide, and a palladium catalyst. The method was further applied to the solid‐phase synthesis wherein the use of a “traceless” sulfonamide linker enabled the rapid preparation of a small library of pyridines with high purity, without any chromatographic separation.
Neurofibromatosis type 1 is a disorder of dysplasia: The importance of distinguishing features, consequences, and complications
Authors: Riccardi Vincent Michael 
Published: August 2009

AbstractBACKGROUND: The disorder neurofibromatosis type 1 (NF1) is caused by mutations in the NF1 gene, which influences the availability of activated Ras and the latter's control of cellular proliferation. Emphasis on this aspect of NF1 has focused attention on the tumor suppression function of NF1 and thereby displaced attention from the gene's role in initial normal tissue formation, maintenance, and repair. METHODS: Clinical and neuroimaging data systematically compiled over more than 30 years are analyzed to document the involvement of multiple organs and tissues, often with an embryonic origin. In addition, recent literature based on selective knockout mouse experiments is cited to corroborate embryonic dysplasia as an element of NF1 pathogenesis. RESULTS: Tissue dysplasia, both ab initio and as part of tissue maintenance and wound healing, is a key clinical and pathogenetic aspect of NF1 and thereby provides a rationale for differentiating the elements of NF1 into features, consequences, and complications. CONCLUSIONS: NF1 is a histogenesis control gene that also has properties that overlap with those of a tumor suppressor gene. Both its neoplastic and dysplastic manifestations become more amenable to understanding and treatment if they are differentiated at three levels—specifically, features, consequences and complications. Birth Defects Research (Part A), 2010. © 2009 Wiley‐Liss, Inc.
LC–MS/MS method for the simultaneous determination of ethyl gallate and its major metabolite in rat plasma
Authors: Gao Shouhong , Zhan Qin , Li Jingxian , Yang Qi , Li Xia , Chen Wansheng , Sun Lianna 
Published: August 2009

AbstractA simple, rapid and sensitive liquid chromatography–tandem mass spectroscopy (LC–MS/MS) method was developed and validated for the determination of ethyl gallate, a pharmacologically active constituent isolated from Lagerstroemia speciosa (Linn.) Pers. This method was used to examine the pharmacokinetics of ethyl gallate and its major metabolite gallic acid in rat plasma using propyl gallate as an internal standard. After precipitation of the plasma proteins with acetonitrile, the analytes were separated on a Zorbax SB‐C18 column (3.5 μm, 2.1 × 50 mm) with an isocratic mobile phase consisted of methanol–acetonitrile–10 mM ammonium acetate (10 : 25 : 65, v/v/v) containing 0.1% formic acid at a flow rate of 0.25 mL/min. The Agilent G6410A triple quadrupole LC/MS system was operated under the multiple‐reaction monitoring mode using the electrospray ionization technique in negative mode. The lower limits of quantification of gallic acid and ethyl gallate of the method were 0.5 and 1.0 ng/mL. The intra‐day and inter‐day accuracy and precision of the assay were less than 8.0%. This method has been applied successfully to a pharmacokinetic study involving the intragastric administration of ethyl gallate to rats. Copyright © 2009 John Wiley & Sons, Ltd.
Identification of the major chemical constituents and their metabolites in rat plasma and various organs after oral administration of effective Erxian Decoction (EXD) fraction by liquid chromatography‐mass spectrometry
Authors: Hu Yong Mei , Wang Yi Tao , Sze Stephen C. W. , Tsang K. W. , Wong H. K. , Liu Qing , Zhong Li Dan , Tong Yao 
Published: August 2009

AbstractA simple and specific LC‐DAD‐ESI‐MS/MS method has been developed and applied for the primary investigation of the chemical constituents absorbed or metabolized in vivo, after the rat oral administration of Erxian Decoction (EXD), a Chinese medicine prescription for menopausal syndromes. Through the online ESI‐MSn analysis, a total of 35 compounds have been identified or tentatively characterized from the seven tested samples, and 13 of them were unambiguously identified through a direct comparison of the retention time, UV spectra and MSn fragmentation patterns with the authentic ones. The results showed that 21 compounds were detected from rat plasma, 20 compounds were detected from rat kidneys and adrenal glands, 19 compounds were detected from rat ovaries, 12 compounds were found in rat intestines, nine compounds were identified from rat livers and nine compounds were detected from rat brains at certain time points after oral administration of the effective EXD fraction. Copyright © 2009 John Wiley & Sons, Ltd.
Influence of different magnetites on properties of magnetic Pseudomonas aeruginosa immobilizates used for biosurfactant production
Authors: Heyd M. , Weigold P. , Franzreb M. , Berensmeier S. 
Published: August 2009

AbstractDuring the last decades, whole‐cell immobilization has been used successfully in many bioprocesses. In particular, it is aimed at implementing continuous production processes, reaching higher production rates, and reusing the biocatalyst. In some cases, effective retention of immobilizates in the bioprocess is not feasible by membranes or sieves due to pore plugging or undesired losses of immobilizates. In the present publication, it is reported about the investigation of magnetic immobilizates of Pseudomonas aeruginosa for application in continuous biosurfactant production of rhamnolipids by foam fractionation and retention of entrained immobilizates by high‐gradient magnetic separation from foam. Different materials and methods were tested with respect to important parameters, such as stability, diffusion properties or magnetic separation. Good magnetic separation of immobilizates was achieved at 5% (w/w) magnetite loading. Best results in terms of homogeneous embedding, good diffusion properties, and stability enhancement vis‐à‐vis pure alginate beads was achieved with alginate beads with embedded Bayoxide® magnetite or MagPrep® silica particles. Although polyurethane immobilizates showed higher stabilities compared with alginate beads, rhamnolipid diffusion in immobilizates was superior in magnetic alginate beads. Regarding bead production, smaller immobilizates were achieved with suspension polymerization compared to droplet extrusion by the JetCutting® technology. In total, magnetic immobilizates are a promising tool for an easier handling of biocatalysts in a continuous biological production process, but they have to be adapted to the current production task.© 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009
Modeling and optimization of microbial hyaluronic acid production by Streptococcus zooepidemicus using radial basis function neural network coupling quantum‐behaved particle swarm optimization algorithm
Authors: Liu Long , Sun Jun , Xu Wenbo , Du Guocheng , Chen Jian 
Published: August 2009

AbstractHyaluronic acid (HA) is a natural biopolymer with unique physiochemical and biological properties and finds a wide range of applications in biomedical and cosmetic fields. It is important to increase HA production to meet the increasing HA market demand. This work is aimed to model and optimize the amino acids addition to enhance HA production of Streptococcus zooepidemicus with radial basis function (RBF) neural network coupling quantum‐behaved particle swarm optimization (QPSO) algorithm. In the RBF‐QPSO approach, RBF neural network is used as a bioprocess modeling tool and QPSO algorithm is applied to conduct the optimization with the established RBF neural network black model as the objective function. The predicted maximum HA yield was 6.92 g/L under the following conditions: arginine 0.062 g/L, cysteine 0.036 g/L, and lysine 0.043 g/L. The optimal amino acids addition allowed HA yield increased from 5.0 g/L of the control to 6.7 g/L in the validation experiments. Moreover, the modeling and optimization capacity of the RBF‐QPSO approach was compared with that of response surface methodology (RSM). It was indicated that the RBF‐QPSO approach gave a slightly better modeling and optimization result compared with RSM. The developed RBF‐QPSO approach in this work may be helpful for the modeling and optimization of the other multivariable, nonlinear, time‐variant bioprocesses. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009
Chiral Salan Aluminium Ethyl Complexes and Their Application in Lactide Polymerization
Authors: Du Hongzhi , Velders Aldrik H. , Dijkstra Pieter J. , Sun Jingru , Zhong Zhiyuan , Chen Xuesi , Feijen Jan 
Published: August 2009

AbstractSynthetic routes to aluminium ethyl complexes supported by chiral tetradentate phenoxyamine (salan‐type) ligands [Al(OC6H2(R‐6‐R‐4)CH2)2{CH3N(C6H10)NCH3}‐C2H5] (4, 7: R=H; 5, 8: R=Cl; 6, 9: R=CH3) are reported. Enantiomerically pure salan ligands 1–3 with (R,R) configurations at their cyclohexane rings afforded the complexes 4, 5, and 6 as mixtures of two diastereoisomers (a and b). Each diastereoisomer a was, as determined by X‐ray analysis, monomeric with a five‐coordinated aluminium central core in the solid state, adopting a cis‐(O,O) and cis‐(Me,Me) ligand geometry. From the results of variable‐temperature (VT) 1H NMR in the temperature range of 220–335 K, 1H–1H NOESY at 220 K, and diffusion‐ordered spectroscopy (DOSY), it is concluded that each diastereoisomer b is also monomeric with a five‐coordinated aluminium central core. The geometry is intermediate between square pyramidal with a cis‐(O,O), trans‐(Me,Me) ligand disposition and trigonal bipyramidal with a trans‐(O,O) and trans‐(Me,Me) disposition. A slow exchange between these two geometries at 220 K was indicated by 1H–1H NOESY NMR. In the presence of propan‐2‐ol as an initiator, enantiomerically pure (R,R) complexes 4–6 and their racemic mixtures 7–9 were efficient catalysts in the ring‐opening polymerization of lactide (LA). Polylactide materials ranging from isotactically biased (Pm up to 0.66) to medium heterotactic (Pr up to 0.73) were obtained from rac‐lactide, and syndiotactically biased polylactide (Pr up to 0.70) from meso‐lactide. Kinetic studies revealed that the polymerization of (S,S)‐LA in the presence of 4/propan‐2‐ol had a much higher polymerization rate than (R,R)‐LA polymerization (kSS/kRR=10.1).
Amino Acid Ionic Liquids as Chiral Ligands in Ligand‐Exchange Chiral Separations
Authors: Liu Qian , Wu Kangkang , Tang Fei , Yao Lihua , Yang Fei , Nie Zhou , Yao Shouzhuo 
Published: August 2009

AbstractRecently, amino acid ionic liquids (AAILs) have attracted much research interest. In this paper, we present the first application of AAILs in chiral separation based on the chiral ligand exchange principle. By using 1‐alkyl‐3‐methylimidazolium L‐proline (L‐Pro) as a chiral ligand coordinated with copper(II), four pairs of underivatized amino acid enantiomers—dl‐phenylalanine (dl‐Phe), dl‐histidine (dl‐His), dl‐tryptophane (dl‐Trp), and dl‐tyrosine (dl‐Tyr)—were successfully separated in two major chiral separation techniques, HPLC and capillary electrophoresis (CE), with higher enantioselectivity than conventionally used amino acid ligands (resolution (Rs)=3.26–10.81 for HPLC; Rs=1.34–4.27 for CE). Interestingly, increasing the alkyl chain length of the AAIL cation remarkably enhanced the enantioselectivity. It was inferred that the alkylmethylimidazolium cations and L‐Pro form ion pairs on the surface of the stationary phase or on the inner surface of the capillary. The ternary copper complexes with L‐Pro are consequently attached to the support surface, thus inducing an ion‐exchange type of retention for the dl‐enantiomers. Therefore, the AAIL cation plays an essential role in the separation. This work demonstrates that AAILs are good alternatives to conventional amino acid ligands for ligand‐exchange‐based chiral separation. It also reveals the tremendous application potential of this new type of task‐specific ILs.
Bonding in Endohedral Metallofullerenes as Studied by Quantum Theory of Atoms in Molecules
Authors: Popov Alexey A. , Dunsch Lothar 
Published: August 2009

AbstractMetal–cage and intracluster bonding was studied in detail by quantum theory of atoms in molecules (QTAIM) for the four major classes of endohedral metallofullerenes (EMFs), including monometallofullerenes Ca@C72, La@C72, M@C82(M=Ca, Sc, Y, La), dimetallofullerenes Sc2@C76, Y2@C82, Y2@C79N, La2@C78, La2@C80, metal nitride clusterfullerenes Sc3N@C2n(2n=68, 70, 78, 80), Y3N@C2n(2n=78, 80, 82, 84, 86, 88), La3N@C2n(2n=88, 92, 96), metal carbide clusterfullerenes Sc2C2@C68, Sc2C2@C82, Sc2C2@C84, Ti2C2@C78, Y2C2@C82, Sc3C2@C80, as well as Sc3CH@C80and Sc4Ox@C80(x=2, 3), that is, 42 EMF molecules and ions in total. Analysis of the delocalization indices and bond critical point (BCP) indicators such asGbcp/ρbcp,Hbcp/ρbcp, and|Vbcp|/Gbcp, revealed that all types of bonding in EMFs exhibit a high degree of covalency, and the ionic model is reasonable only for the Ca‐based EMFs. Metal–metal bonds with negative values of the electron‐density Laplacian were found in Y2@C82, Y2@C79N, Sc4O2@C80, and anionic forms of La2@C80. A delocalized nature of the metal–cage bonding results in a topological instability of the electron density in EMFs with an unpredictable number of metal–cage bond paths and large elipticity values.
Synthesis of (−)‐Cubebol by Face‐Selective Platinum‐, Gold‐, or Copper‐Catalyzed Cycloisomerization: Evidence of Chirality Transfer and Mechanistic Insights
Authors: Fehr Charles , Winter Beat , Magpantay Iris 
Published: August 2009

AbstractWe describe in detail a direct, stereoselective synthesis of (−)‐cubebol based on a Pt‐, Au‐, or Cu‐catalyzed cycloisomerization in which control of the configuration of the propargylic center is essential for the facial selectivity. In addition, we show that cycloisomerization reactions of enantioenriched propargyl pivalates occur with substantial chirality transfer. We confirm a mechanism by means of cyclization followed by an [1,2]‐acyl migration for the Pt‐ and the Au‐catalyzed cycloisomerization. So far, no evidence supports that the Cu‐catalyzed cycloisomerization follows the same reaction course.
Assessment of factors that contribute to decreased quality of life in Gynecologic Oncology Group ovarian cancer trials
Authors: von Gruenigen Vivian E. , Huang Helen Q. , Gil Karen M. , Gibbons Heidi E. , Monk Bradley J. , Rose Peter G. , Armstrong Deborah K. , Cella David , Wenzel Lari 
Published: August 2009

AbstractBACKGROUND:The objective of this study was to assess which quality‐of‐life (QOL) line items on the Functional Assessment of Cancer Therapy‐Ovarian (FACT‐O) were associated with low QOL in women who were receiving chemotherapy for ovarian cancer.METHODS:Patients with stage III or IV ovarian cancer on Gynecologic Oncology Group Protocols 152 and 172 who underwent primary surgery followed by intravenous paclitaxel and cisplatin completed the FACT‐O. The FACT scale includes the 4 domains of physical, functional, social, and emotional well being (PWB, FWB, SWB, EWB, respectively). Women who had overall FACT‐O scores in the lowest quartile (Q1) were compared with women in the upper 3 quartiles (Q2‐Q4). The proportions of women in each group that selected the 2 worst categories for each item were compared. The level of significance was set at P < .005.RESULTS:Before Cycle 4, 361 patients (86.4%) provided valid QOL assessments. For PWB, a significantly greater proportion of women in Q1 versus Q2 through Q4 selected the 2 worst categories of several physical symptoms (nausea, pain, feeling ill, and being bothered by the side effects of treatment). For FWB, significant differences included being able to work, being content with the quality of their life, and sleeping well. For EWB, there were significant differences in feeling nervous and worrying about dying. There were virtually no differences between groups in SWB. Low interest in sex was reported by 56% to 88% of all patients (Q1‐Q4).CONCLUSIONS:A large proportion of women with FACT‐O scores in the lowest quartile reported problems that potentially were amenable to clinical interventions, such as symptom management and psychosocial support. Cancer 2009. © 2009 American Cancer Society.
The heterogeneous prognosis of patients with myelodysplastic syndrome and chromosome 5 abnormalities
Authors: Kantarjian Hagop , O'Brien Susan , Ravandi Farhad , Borthakur Gautam , Faderl Stefan , Bueso‐Ramos Carlos , Abruzzo Lynne , Pierce Sherry , Shan Jianqin , Issa Jean‐Pierre , Garcia‐Manero Guillermo 
Published: August 2009

AbstractBACKGROUND:To define the prognosis in myelodysplastic syndrome (MDS) and deletion 5q with or without other cytogenetic abnormalities.METHODS:Patients with MDS (<20% blasts) and evaluable cytogenetic studies (1966‐present) were reviewed. Outcome of patients with deletion 5q or with loss of chromosome 5 (monosomy 5) was analyzed.RESULTS:Of 2743 patients analyzed, 287 (10%) had deletion 5q and 216 (8%) had monosomy 5 abnormalities. The median survival was 9 months with deletion 5q, 6 months with monosomy 5, and 17 months without a chromosome 5 abnormality. Considering patients with deletion 5q, the median survival was 33 months with deletion 5q alone, 17 months with deletion 5q and 1 additional abnormality, but only 6 months to 12 months with deletion 5q and ≥2 abnormalities or chromosome 7 abnormality. Only 93 patients (3.4% of total) had lower risk MDS (international prognostic scoring system low or intermediate 1) and deletion 5q; their median survival was 29 months (2‐year survival 60%), and ranged from 13‐41 months depending on the presence or absence of additional chromosomal abnormalities. Among 198 patients with MDS with deletion 5q and <10% blasts (a subset now often offered lenalidomide), the median survival was 12 months. Monosomy 5 was significantly more frequently associated with advanced MDS and with other chromosomal abnormalities.CONCLUSIONS:This study provided baseline expectations of outcome in different MDS subsets and deletion 5q. Cancer 2009. © 2009 American Cancer Society.
Prognostic role of pregnancy occurring before or after treatment of early breast cancer patients aged <35 years
Authors: Largillier Rémy , Savignoni Alexia , Gligorov Joseph , Chollet Philippe , Guilhaume Marie‐Noëlle , Spielmann Marc , Luporsi Elisabeth , Asselain Bernard , Coudert Bruno , Namer Moïse ,   on behalf of the GET(N)A Group
Published: August 2009

AbstractBACKGROUND:Usual practices recommend waiting at least 2 years between diagnosis of early breast cancer (EBC) and pregnancy. Few data highlighted a harmful effect of an early pregnancy for low‐risk patients. The authors analyzed retrospectively data from women younger than 35 years who became pregnant before or after treatment of EBC.METHODS:Between 1990 and 1999, 908 consecutive EBC patients were analyzed. The primary endpoint was to compare overall survival (OS) between pregnant and nonpregnant patients. The secondary endpoint was to establish a score index laying down the risk of distant recurrence.RESULTS:Within the year before the diagnosis, 105 (11.6%) patients became pregnant and 118 (13%) were pregnant after treatment. In a multivariate model, a pregnancy before the diagnosis was not predictive of death but of local relapse. A pregnancy subsequent to breast cancer therapy resulted in a 77% decrease of death (P < .001). In good‐prognosis score index patients, the annual risk of relapse remained low. In patients having the higher score, recurrences occurred mainly during the first years after the treatment. Beyond 80 months, the annual risk of relapse seemed to be similar to those of lower‐risk subgroups.CONCLUSIONS:In women aged younger than 35 years, a pregnancy occurring before or after the diagnosis of breast cancer was not an independent prognostic factor of death. In the subset of patients having a high risk of relapse, it may be preferable to postpone a pregnancy beyond 5 years after the breast cancer therapy. Cancer 2009. © 2009 American Cancer Society.
A rigidity result for a perturbation of the geometrically linear three‐well problem
Authors: Capella Antonio , Otto Felix 
Published: August 2009

AbstractWe study a three‐dimensional model for alloys that undergo a cubic‐to‐tetragonal phase transition in the martensitic phase. Any pair of the three martensitic variants can form a stress‐free laminate. However, this laminate is only compatible on average with the remaining variant. The resulting local stresses favor a microstructure if all three variants are present (for instance, because of an externally imposed average strain).Next to the linearized elastic energy, the variational model features an interfacial energy between the three variants. This introduces a material length scale, which together with the sample size (which we mimic by periodic boundary conditions) gives rise to a nondimensional parameter η.We rigorously establish the scaling of the minimal energy e per volume in case of externally imposed volume fractions of the martensitic variants in η. More precisely, we show e ∼ η2/3. The upper bound construction is achieved by a few patches of branched laminates; the lower bound relies on suitable interpolation inequalities. This is in the spirit of a celebrated work by Kohn and Müller and relies on techniques developed for domain branching in micromagnetics.We also prove a rigidity result in the sense that if the energy per volume e of a configuration is much smaller than η2/3, the configuration is approximately a simple unbranched laminate. In particular, one of the three volume fractions has to be small. This is related to similar rigidity results by Dolzmann and Müller and by Kirchheim. © 2009 Wiley Periodicals, Inc.
Optimizing execution path of scientific workflow by gradual removal of QoS constraint violations in Reverse Order
Authors: Ren Kaijun , Chen Jinjun 
Published: August 2009

AbstractA service‐based scientific workflow can be exposed as a composite service that consists of a set of logically connected sub‐services. A critical issue in this area is how to achieve overall optimized end‐to‐end QoS requirements by effectively coordinating individual QoS constraints of single service. Unfortunately, this issue has not been well addressed. In this paper, we propose a Reverse Order‐based approach to gradually remove QoS Constraint violations for building an optimized path to execute a scientific workflow. With our approach, an initial execution path for a scientific workflow is first built by employing the local optimization policy without considering user‐defined end‐to‐end QoS constraints. Based on this path, global QoS computing models can be used to calculate the global QoS values for each quality attribute. Then, QoS constraint violations can be detected by comparing global QoS values with end‐to‐end user‐defined QoS constraints. For each violation, a Reverse Order‐based correction algorithm by gradually removing QoS constraint violations is proposed to recursively correct it by reselecting critical service execution instances. As a result, an optimized execution path can be rebuilt to meet overall end‐to‐end QoS requirements. Comparison and simulation further demonstrate the feasibility and performance of our approach. Copyright © 2009 John Wiley & Sons, Ltd.