bluuebunny/crossref_metadata_2025_split huggingface dataset:
Induction of chondrogenesis from human embryonic stem cells without embryoid body formation by bone morphogenetic protein 7 and transforming growth factor β1
Authors: Nakagawa Toshiyuki , Lee Sang Yang , Reddi A. Hari 
Published: November 2009

AbstractObjectiveHuman embryonic stem cells (ESCs) provide an unlimited supply of pluripotent cells for articular cartilage tissue engineering and regenerative medicine applications. Articular cartilage is an avascular tissue with precise polarity and organization comprising 3 distinct functional zones: surface, middle, and deep. To date, attempts at differentiating human ESCs into articular chondrocytes have been unsuccessful. The majority of studies have focused on chondrogenic (but not specifically articular cartilage) differentiation. Furthermore, previous investigations of induction of chondrogenesis by human ESCs required embryoid body formation; however, embryoid body formation often results in heterogeneous differentiation. The present study was undertaken to determine the in vitro chondrogenic potential of bone morphogenetic protein 7 (BMP‐7) and transforming growth factor β1 (TGFβ1)–induced human ESC differentiation toward the articular cartilage phenotype.MethodsDissociated single human ESCs were cultured and passaged on a gelatin‐coated flask. The human ESCs were cultured as an aggregate in a pellet culture system for 14 days in basal chondrogenic medium (CM), CM with TGFβ1, CM with BMP‐7, or CM with both TGFβ1 and BMP‐7.ResultsThe size and wet weight of the cartilage pellets and glycosaminoglycan levels increased, with the smallest, intermediate, and greatest increases, respectively, observed with CM plus TGFβ1 treatment, CM plus BMP‐7 treatment, and CM plus TGFβ1 and BMP‐7 treatment (compared with CM treatment alone). The largest size and highest weight of the pellet was in the group in which TGFβ1 and BMP‐7 were added to the medium. However, expression of the genes for cartilage‐specific aggrecan and type II collagen II, as assessed by determination of messenger RNA levels, was highest in the BMP‐7–treated group. Superficial zone protein (SZP)/lubricin, a marker of the superficial zone articular chondrocyte, was not detectable under identical culture conditions.ConclusionThese results demonstrate an efficient and reproducible model system of human ESC‐induced chondrogenesis, using a novel direct plating method in which intervening embryoid body formation does not occur. Further work is needed for optimization of conditions to obtain the articular cartilage phenotype that includes the superficial zone marker as demonstrated by SZP/lubricin synthesis.
A note on transfer function model specification with noisy closed‐loop input data
Authors: Ledolter Johannes 
Published: November 2009

AbstractWe assume that the input in a transfer function noise model is determined by a proportional‐integral‐derivative controller that is subject to noise. We show how such a noisy feedback in the input series affects the standard Box–Jenkins method of specifying the transfer function model. Our findings have important implications for the analyst who uses the traditional Box–Jenkins approach. The analyst will be led to estimate an incorrect transfer function model if feedback (exact or noisy) is present. Copyright © 2009 John Wiley & Sons, Ltd.
Cell surface display of highly pathogenic avian influenza virus hemagglutinin on the surface of Pichia pastoris cells using α‐agglutinin for production of oral vaccines
Authors: Wasilenko Jamie L. , Sarmento Luciana , Spatz Stephen , Pantin‐Jackwood Mary 
Published: November 2009

AbstractYeast is an ideal organism to express viral antigens because yeast glycosylate proteins more similarly to mammals than bacteria. Expression of proteins in yeast is relatively fast and inexpensive. In addition to the convenience of production, for purposes of vaccination, yeast has been shown to have natural adjuvant activity making the expressed proteins more immunogenic when administered along with yeast cell wall components. Development of genetic systems to display foreign proteins on the surface of yeast via fusion to glycosylphosphatidylinositol‐anchored (GPI) proteins has further simplified the purification of recombinant proteins by not requiring harsh treatments for cellular lysis or protein purification. We have expressed the hemagglutinin protein from a highly pathogenic avian influenza (HPAI) virus [A/Egret/HK/757.2/02], subtype H5N1, on the surface of the yeast strain Pichia pastoris, as an anchored C‐terminal fusion with the Saccharomyces cerevisiae GPI‐anchored cell wall protein, α‐agglutinin. Surface expression of the hemagglutinin fusion protein was demonstrated by immunofluorescence microscopy. Functionally, the fusion protein retained hemagglutinin agglutinating activity, and oral vaccination with the yeast resulted in production of virus neutralizing antibodies. This study represents the first steps in the generation of a yeast‐based vaccine for protection against highly pathogenic strains of avian influenza. Published 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2010
A fuzzy system for evaluating students' project in engineering education
Authors: Baba A. Fevzi , Cin F. Melis , Bakanay Didem 
Published: November 2009

AbstractFuzzy group decision support system is an approach developed to assess the performance of engineering education students. This approach provides multiple perspectives of different people and prevents subjectivity in the evaluation process. It also enables students to take active roles in the assessment. Hence, unbiased evaluation is aimed to be promoted. The developed software for the specific purpose of this study is user‐friendly and has multi‐criteria decision dimension. The pedagogical implication and aspect of the study have also been displayed in the case study part. The results of the study reveal that fuzzy logic has been influential in increasing the quality of education facilities, motivation, reliability, consistency, and objectivity of the assessment. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 20: 287–294, 2012
NBD‐Based Green Fluorescent Ligands for Typing of Thymine‐Related SNPs by Using an Abasic Site‐Containing Probe DNA
Authors: Thiagarajan Viruthachalam , Rajendran Arivazhagan , Satake Hiroyuki , Nishizawa Seiichi , Teramae Norio 
Published: November 2009

AbstractThe binding behavior of green fluorescent ligands, derivatives of 7‐nitrobenzo‐2‐oxa‐1,3‐diazole (NBD), with DNA duplexes containing an abasic (AP) site is studied by thermal denaturation and fluorescence experiments. Among NBD derivatives, N1‐(7‐nitrobenzo[c][1,2,5]oxadiazol‐4‐yl)propane‐1,3‐diamine (NBD‐NH2) is found to bind selectively to the thymine base opposite an AP site in a DNA duplex with a binding affinity of 1.52×106 M−1. From molecular modeling studies, it is suggested that the NBD moiety binds to thymine at the AP site and a protonated amino group tethered to the NBD moiety interacts with the guanine base flanking the AP site. Green fluorescent NBD‐NH2 is successfully applied for simultaneous G>T genotyping of PCR amplification products in a single cuvette in combination with a blue fluorescent ligand, 2‐amino‐6,7‐dimethyl‐4‐hydroxypteridine (diMe‐pteridine).
Determination of Optimum Conditions and the Kinetics of Methanol Oxidation
Authors: Ulukardesler A. H. , Atalay S. , Atalay F. S. 
Published: November 2009

AbstractIn this study, the catalytic oxidation of methanol to formaldehyde was investigated in a laboratory‐scale fixed‐bed catalytic reactor, under a large number of different conditions. Iron‐molybdate catalysts supported by silica or alumina with a molybdenium/iron (Mo/Fe) ratio of 1.5, 3 and 5 were studied for the gas phase reaction. In order to obtain the optimum conditions, six different temperatures in the range of 250–375 °C and three different space times of 50.63, 33.75 and 20.25 g/(mol/h) were investigated. After determining the optimum conditions for this reaction, experiments aimed at understanding the reaction kinetics, were carried out. These experiments were performed on the catalyst favoring the formation of formaldehyde, which has a (Mo/Fe) ratio of 5 on a silica support. Seven reaction models derived by the mechanisms cited in the literature were tested to elucidate the kinetics of the reaction and the surface reaction controlling model was found to be the most suitable reaction mechanism.
Multimode process monitoring based on Bayesian method
Authors: Ge Zhiqiang , Song Zhihuan 
Published: November 2009

AbstractMultimode process monitoring has recently attracted much attention both in academy and industry. Conventional methods assume that either the process data are Gaussian in each operation mode, or some process knowledge should be incorporated, thus making the methods supervised. In this paper, a new unsupervised method is developed for multimode process monitoring, which is based on Bayesian inference and two‐step independent component analysis–principal component analysis (ICA–PCA) feature extraction strategy. ICA–PCA is first introduced for feature extraction and dimension reduction. By transferring the traditional monitoring statistic to fault probability in each operation mode, monitoring results in different operation modes can be easily combined by the Bayesian inference. Another contribution of the present paper is the development of a new fault identification method. Through analyses of the posterior probability and the joint probability for the monitored data sample, the correct operation mode or fault scenario can be identified. Three case studies are demonstrated to evaluate the feasibility and efficiency of the proposed method. Copyright © 2009 John Wiley & Sons, Ltd.
The Role of Transferrin in Actinide(IV) Uptake: Comparison with Iron(III)
Authors: Jeanson Aurélie , Ferrand M. , Funke Harald , Hennig Christoph , Moisy Philippe , Solari Pier Lorenzo , Vidaud Claude , Den Auwer Christophe 
Published: November 2009

AbstractThe impact of actinides on living organisms has been the subject of numerous studies since the 1950s. From a general point of view, these studies show that actinides are chemical poisons as well as radiological hazards. Actinides in plasma are assumed to be mainly complexed to transferrin, the iron carrier protein. This paper casts light on the uptake of actinides(IV) (thorium, neptunium, plutonium) by transferrin, focusing on the pH dependence of the interaction and on a molecular description of the cation binding site in the protein. Their behavior is compared with that of iron(III), the endogenous transferrin cation, from a structural point of view. Complementary spectroscopic techniques (UV/Vis spectrophotometry, microfiltration coupled with γ spectrometry, and X‐ray absorption fine structure) have been combined in order to propose a structural model for the actinide‐binding site in transferrin. Comparison of our results with data available on holotransferrin suggests some similarities between the behavior of FeIII and NpIV/PuIV/ NpIV is not complexed at pH <7, whereas at pH ≈7.4 complexation can be regarded as quantitative. This pH effect is consistent with the in vivo transferrin “cycle”. PuIV also appears to be quantitatively bound by apotransferrin at around pH ∼7.5, whereas ThIV was never complexed under our experimental conditions. EXAFS data at the actinide edge have allowed a structural model of the actinide binding site to be elaborated: at least one tyrosine residue could participate in the actinide coordination sphere (two for iron), forming a mixed hydroxo–transferrin complex in which actinides are bound with transferrin both through An–tyrosine and through AnOH bonds. A description of interatomic distances is provided.
Computationally Designed Families of Flat, Tubular, and Cage Molecules Assembled with “Starbenzene” Building Blocks through Hydrogen‐Bridge Bonds
Authors: Wu Yan‐Bo , Jiang Jin‐Liang , Zhang Ren‐Wu , Wang Zhi‐Xiang 
Published: November 2009

AbstractUsing density functional calculations, we demonstrate that the planarity of the nonclassical planar tetracoordinate carbon (ptC) arrangement can be utilized to construct new families of flat, tubular, and cage molecules which are geometrically akin to graphenes, carbon nanotubes, and fullerenes but have fundamentally different chemical bonds. These molecules are assembled with a single type of hexagonal blocks called starbenzene (D6h C6Be6H6) through hydrogen‐bridge bonds that have an average bonding energy of 25.4–33.1 kcal mol−1. Starbenzene is an aromatic molecule with six π electrons, but its carbon atoms prefer ptC arrangements rather than the planar trigonal sp2 arrangements like those in benzene. Various stability assessments indicate their excellent stabilities for experimental realization. For example, one starbenzene unit in an infinite two‐dimensional molecular sheet lies on average 154.1 kcal mol−1 below three isolated linear C2Be2H2 (global minimum) monomers. This value is close to the energy lowering of 157.4 kcal mol−1 of benzene relative to three acetylene molecules. The ptC bonding in starbenzene can be extended to give new series of starlike monocyclic aromatic molecules (D4h C4Be4H42−, D5h C5Be5H5−, D6h C6Be6H6, D7h C7Be7H7+, D8h C8Be8H82−, and D9h C9Be9H9−), known as starenes. The starene isomers with classical trigonal carbon sp2 bonding are all less stable than the corresponding starlike starenes. Similarly, lithiated C5Be5H5 can be assembled into a C60‐like molecule. The chemical bonding involved in the title molecules includes aromaticity, ptC arrangements, hydrogen‐bridge bonds, ionic bonds, and covalent bonds, which, along with their unique geometric features, may result in new applications.
Synthesis and Application of Modular Phosphine–Phosphoramidite Ligands in Asymmetric Hydroformylation: Structure–Selectivity Relationship
Authors: Zhang Xiaowei , Cao Bonan , Yan Yongjun , Yu Shichao , Ji Baoming , Zhang Xumu 
Published: November 2009

AbstractA series of hybrid phosphine–phosphoramidite ligands has been designed and synthesized in moderate yields from chiral BINOL (1,1′‐bi‐2‐naphthol) or NOBIN (2‐amino‐2′‐hydroxy‐1,1′‐binaphthyl). They have achieved highly regio‐ and enantioselectivities in Rh‐catalyzed asymmetric hydroformylations of styrene derivatives (branched/linear ratio up to 56.6, ee up to 99 %), vinyl acetate derivatives (up to 98 % ee), and allyl cyanide (up to 96 % ee). Systematic variation of ligand structure showed that the steric factor on the phsophoramidite moiety determined the performance of the ligand. With the increased hindrance, the branched/linear ratio rose, while the ee value dropped in the hydroformylation of styrene. However, the N‐substituents did not influence the selectivities much.
Red‐Emitting Rhodamine Dyes for Fluorescence Microscopy and Nanoscopy
Authors: Kolmakov Kirill , Belov Vladimir N. , Bierwagen Jakob , Ringemann Christian , Müller Veronika , Eggeling Christian , Hell Stefan W. 
Published: November 2009

AbstractFluorescent markers emitting in the red are extremely valuable in biological microscopy since they minimize cellular autofluorescence and increase flexibility in multicolor experiments. Novel rhodamine dyes excitable with 630 nm laser light and emitting at around 660 nm have been developed. The new rhodamines are very photostable and have high fluorescence quantum yields of up to 80 %, long excited state lifetimes of 3.4 ns, and comparatively low intersystem‐crossing rates. They perform very well both in conventional and in subdiffraction‐resolution microscopy such as STED (stimulated emission depletion) and GSDIM (ground‐state depletion with individual molecular return), as well as in single‐molecule‐based experiments such as fluorescence correlation spectroscopy (FCS). Syntheses of lipophilic and hydrophilic derivatives starting from the same chromophore‐containing scaffold are described. Introduction of two sulfo groups provides high solubility in water and a considerable rise in fluorescence quantum yield. The attachment of amino or thiol reactive groups allows the dyes to be used as fluorescent markers in biology. Dyes deuterated at certain positions have narrow and symmetrical molecular mass distribution patterns, and are proposed as new tags in MS or LC‐MS for identification and quantification of various substance classes (e.g., amines and thiols) in complex mixtures. High‐resolution GSDIM images and live‐cell STED‐FCS experiments on labeled microtubules and lipids prove the versatility of the novel probes for modern fluorescence microscopy and nanoscopy.
Propargyl Amine Synthesis Catalysed by Gold and Copper Thin Films by Using Microwave‐Assisted Continuous‐Flow Organic Synthesis (MACOS)
Authors: Shore Gjergji , Yoo Woo‐Jin , Li Chao‐Jun , Organ Michael G. 
Published: November 2009

AbstractAn effective multi‐component reaction (MCR) protocol has been developed for the construction of propargyl amines from aldehydes, amines and terminal alkynes by using microwave‐assisted continuous‐flow organic synthesis (MACOS). The process is catalysed by thin films of either copper or gold that achieve temperatures in excess of 900 °C when irradiated with low levels of microwave power. The process works equally well for premixed solutions of the three starting materials, or as three separate streams, which improves the combinatorial efficiency of the method. The process tolerates a wide variety of functional groups and heterocycles, and conversion over these diverse substrates ranges from 70–90 %.
β‐Diketiminate‐Stabilized Magnesium(I) Dimers and Magnesium(II) Hydride Complexes: Synthesis, Characterization, Adduct Formation, and Reactivity Studies
Authors: Bonyhady Simon J. , Jones Cameron , Nembenna Sharanappa , Stasch Andreas , Edwards Alison J. , McIntyre Garry J. 
Published: November 2009

AbstractThe preparation and characterization of a series of magnesium(II) iodide complexes incorporating β‐diketiminate ligands of varying steric bulk and denticity, namely, [(ArNCMe)2CH]− (Ar=phenyl, (PhNacnac), mesityl (MesNacnac), or 2,6‐diisopropylphenyl (Dipp, DippNacnac)), [(DippNCtBu)2CH]− (tBuNacnac), and [(DippNCMe)(Me2NCH2CH2NCMe)CH]− (DmedaNacnac) are reported. The complexes [(PhNacnac)MgI(OEt2)], [(MesNacnac)MgI(OEt2)], [(DmedaNacnac)MgI(OEt2)], [(MesNacnac)MgI(thf)], [(DippNacnac)MgI(thf)], [(tBuNacnac)MgI], and [(tBuNacnac)MgI(DMAP)] (DMAP=4‐dimethylaminopyridine) were shown to be monomeric by X‐ray crystallography. In addition, the related β‐diketiminato beryllium and calcium iodide complexes, [(MesNacnac)BeI] and [{(DippNacnac)CaI(OEt2)}2] were prepared and crystallographically characterized. The reductions of all metal(II) iodide complexes by using various reagents were attempted. In two cases these reactions led to the magnesium(I) dimers, [(MesNacnac)MgMg(MesNacnac)] and [(tBuNacnac)MgMg(tBuNacnac)]. The reduction of a 1:1 mixture of [(DippNacnac)MgI(OEt2)] and [(MesNacnac)MgI(OEt2)] with potassium gave a low yield of the crystallographically characterized complex [(DippNacnac)Mg(μ‐H)(μ‐I)Mg(MesNacnac)]. All attempts to form beryllium(I) or calcium(I) dimers by reductions of [(MesNacnac)BeI], [{(DippNacnac)CaI(OEt2)}2], or [{(tBuNacnac)CaI(thf)}2] have so far been unsuccessful. The further reactivity of the magnesium(I) complexes [(MesNacnac)MgMg(MesNacnac)] and [(tBuNacnac)MgMg(tBuNacnac)] towards a variety of Lewis bases and unsaturated organic substrates was explored. These studies led to the complexes [(MesNacnac)Mg(L)Mg(L)(MesNacnac)] (L=THF or DMAP), [(MesNacnac)Mg(μ‐AdN6Ad)Mg(MesNacnac)] (Ad=1‐adamantyl), [(tBuNacnac)Mg(μ‐AdN6Ad)Mg(tBuNacnac)], and [(MesNacnac)Mg(μ‐tBu2N2C2O2)Mg(MesNacnac)] and revealed that, in general, the reactivity of the magnesium(I) dimers is inversely proportional to their steric bulk. The preparation and characterization of [(tBuNacnac)Mg(μ‐H)2Mg(tBuNacnac)] has shown the compound to have different structural and physical properties to [(tBuNacnac)MgMg(tBuNacnac)]. Treatment of the former with DMAP has given [(tBuNacnac)Mg(H)(DMAP)], the X‐ray crystal structure of which disclosed it to be the first structurally authenticated terminal magnesium hydride complex. Although attempts to prepare [(MesNacnac)Mg(μ‐H)2Mg(MesNacnac)] were not successful, a neutron diffraction study of the corresponding magnesium(I) complex, [(MesNacnac)MgMg(MesNacnac)] confirmed that the compound is devoid of hydride ligands.
Calix[4]arene‐Based Rotaxane Host Systems for Anion Recognition
Authors: McConnell Anna J. , Serpell Christopher J. , Thompson Amber L. , Allan David R. , Beer Paul D. 
Published: November 2009

AbstractThe synthesis, structure and anion binding properties of the first calix[4]arene‐based [2]rotaxane anion host systems are described. Rotaxanes 9⋅Cl and 12⋅Cl, consisting of a calix[4]arene functionalised macrocycle wheel and different pyridinium axle components, are prepared via adaption of an anion templated synthetic strategy to investigate the effect of preorganisation of the interlocked host’s binding cavity on anion binding. Rotaxane 12⋅Cl contains a conformationally flexible pyridinium axle, whereas rotaxane 9⋅Cl incorporates a more preorganised pyridinium axle component. The X‐ray crystal structure of 9⋅Cl and solution phase 1H NMR spectroscopy demonstrate the successful interlocking of the calix[4]arene macrocycle and pyridinium axle components in the rotaxane structures. Following removal of the chloride anion template, anion binding studies on the resulting rotaxanes 9⋅PF6 and 12⋅PF6 reveal the importance of preorganisation of the host binding cavity on anion binding. The more preorganised rotaxane 9⋅PF6 is the superior anion host system. The interlocked host cavity is selective for chloride in 1:1 CDCl3/CD3OD and remains selective for chloride and bromide in 10 % aqueous media over the more basic oxoanions. Rotaxane 12⋅PF6 with a relatively conformationally flexible binding cavity is a less effective and discriminating anion host system although the rotaxane still binds halide anions in preference to oxoanions.
Hyperpolarizabilities of Chelidamic Acid Complexes Mm(C7H3O5N)n (MCu, Ag): Theoretical Analysis
Authors: Zhang Xin , Zhou Guowei , Tan Kai , Zhou Guocong , Lin Menghai , Zhang Qianer 
Published: November 2009

AbstractThe frequency‐dependent hyperpolarizabilities of chelidamic acid complexes Mm(C7H3O5N)n (MCu, Ag) were investigated under the time dependent density functional theory (TDDFT) combined with the sum‐over‐states method (SOS). The relationship between molecular orbitals and nonlinear optical (NLO) properties has been explored. The results show that the charge transitions of π‐π* and 3dM‐π* are very important to the second‐order polarizabilities, and the largest component of dynamic β is 3.84×10−25 cm5·esu−1 at 0.74 eV for Ag2Cu2(C7H3O5N)4. The charge transition between π‐π* is also highly crucial to the third‐order polarizabilities, and the largest component of dynamic γ is −4.46×10−29 esu at 0.50 eV for Ag2Cu2(C7H3O5N)4. The central Cu ion, as electron bridge, extends the range of delocalization and leads to an interesting phenomenon of spiroconjugation.