bluuebunny/crossref_metadata_2025 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

Objective

Human 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.

Methods

Dissociated 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.

Results

The 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.

Conclusion

These 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

We 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

Yeast 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

Fuzzy 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

The 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

In 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

Multimode 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

The 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

Using 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

A 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

Fluorescent 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

An 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

The 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

The 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

The 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.
Study of the Influence of Different Diphenol Compounds on Soil Microbial Activity by Microcalorimetry
Authors: Chen Huilun , Yao Jun , Wang Fei , Gyula Zaray
Published: November 2009

Microcalorimetry was applied to follow the toxic effects caused by different diphenol compounds on microbial activity of Chinese fir soil. The activity of the microorganisms in soil was stimulated by adding 0.3 mL of a nutrient solution containing 2.5 mg of glucose and 2.5 mg of ammonium sulfate and the measurements were performed under a 35% controlled humidity at 28°C. Power‐time curves recorded on a microcalorimeter were followed by increasing the amount of diphenol compounds, which affected directly the total thermal effects evolved by the microorganisms. The curves showed a synergism on total thermal effect obtained by the addition of 2000 mg·kg−1 of resorcinol, causing a consumption of resorcinol by the microorganisms as a new source of nutrients. Above this dose, the total thermal effect decreased exponentially. However, the addition of catechol and hydroquinone caused the total thermal effects to decrease directly. It was concluded that the increase in the diphenol concentration strongly affected the microbial life in this ecosystem. Microcalorimetry appears as a suitable technique to carry out both qualitative and quantitative comparative studies of microbial activity in soil.
Estimation of Critical Temperature of Thermal Explosion for Nitrosubstituted Azetidines Using Non‐isothermal DSC
Authors: Hu Rongzu , Zhao Fengqi , Gao Hongxu , Zhang Jiaoqiang , Zhang Hai , Zhang Haixia
Published: November 2009

Based on reasonable hypothesis, two general expressions and their six derived formulae for estimating the critical temperature (Tb) of thermal explosion for energetic materials (EM) were derived from the Semenov's thermal explosion theory and eight non‐isothermal kinetic equations. We can easily obtain the values of the initial temperature (T0i) at which DSC curve deviates from the baseline of the non‐isothermal DSC curve of EM, the onset temperature (Tei), the exothermic decomposition reaction kinetic parameters and the values of T00 and Te0 from the equation T0i or ei=T00 or e0+a1βi+a2βi2+···+aL−2βiL−2, i=1, 2, ;···, L and then calculate the values of Tb by the six derived formulae. The Tb values for seven nitrosubstituted azetidines, 3,3‐dinitroazetidinium nitrate (1), 3,3‐dinitroazetidinium picrate (2), 3,3‐dinitroazetidinium‐3‐nitro‐1,2,4‐triazol‐5‐onate (3), 1,3‐bis(3′,3′‐dinitroazetidine group)‐2,2‐dinitropropane (4), 1‐(2′,2′,2′‐trinitroethyl)‐3,3‐dinitroazetidine (5), 3,3‐dinitroazetidinium perchlorate (6) and 1‐(3′,3′‐dinitroazetidineyl)‐2,2‐dinitropropane (7), obtained with the six derived formulae are agreeable to each other, whose differences are within 1.5%. The results indicate that the heat‐resistance stability of the seven nitrosubstituted azetidines decreases in the order 6>7>5>4>3>2>1.
Comparison of Immobilization Modes in pH‐Sensitive Phase Separation Immunoassay
Authors: Lin Peng , Guo Songlin , Wang Yilei , Wang Weigang , Chen Jinming , Jia Xiwei , Wang Guodong
Published: November 2009

Three immobilization modes of antigen to the polymers in the pH‐sensitive phase separation immunoassay were investigated and compared. The results showed that the immobilization mode in the presence of N‐ethyl‐N′‐(3‐dimethylaminopropyl)carbodiimide hydrochloride (EDCI) rendered the most desirable results. The immobilization efficiencies and immunological reaction activities of immobilized antigen of this mode were improved over the other two modes. The novel immobilization mode by EDCI was used in the pH‐sensitive phase separation immunoassay for rabbit IgG (Ag). In the competitive immunoassay, immobilized Ag and the standard Ag (or sample) competed for binding to a horseradish peroxidase labeled antibody at 37°C in a homogeneous format. After changing the pH to separate the polymer‐immune complex, the complex precipitate was re‐dissolved and determined by coupling with the color reaction of hydrogen peroxide and o‐phenylenediamine. The linear range of this determination was between 100–1400 ng/mL. Compared to the traditional enzyme‐linked immunosorbent assays (ELISA) using the same reactants, the proposed method was quiet fast (the time decreased from 100−120 to 30 min) and showed similar sensitivity, i.e., 6.0 ng/mL.
Reactivity‐based One‐pot Synthesis of Immunosuppressive Glycolipids from the Caribbean Sponge Plakortis simplex
Authors: Lü Guokai , Wang Peng , Liu Qingchao , Zhang Zaihong , Zhang Wei , Li Yingxia
Published: November 2009

The first synthesis of three natural glycolipid simplexides 1a–1c, which were isolated from the marine sponge Plakortis simplex and claimed to inhibit T cell proliferation, has been concisely accomplished by a reactivity‐based one‐pot synthetic strategy under the use of p‐toluenethioglycoside (STol) donors.
Biomimetic Nucleation and Morphology Control of CaCO3 in PAAm Hydrogels Synthesized from Lyotropic Liquid Crystalline Templates
Authors: Du Zhuwei , Lu Cuixiang , Li Haoran , Li Dingjie
Published: November 2009

Hydrogels have been thought to be the material which can provide appealing replacements of biological organisms. Pores of hydrogels synthesized from lyotropic liquid crystalline (LLC) templates were smaller in size and more uniform than those of traditional hydrogels. LLC poly‐acrylamide (PAAm) hydrogels were used as the growth media of CaCO3. After copolymerized with acrylic acid and 2‐acrylamido‐2‐methylpropanesulfonic acid (AMPS), LLC hydrogels were modified with COOH and SO3H, respectively. The effect of functional groups on the biomimetic mineralization of CaCO3 was studied. Most of crystals from traditional hydrogels are rhombohedral and could not form aggregates. Only a few could aggregate and have a particular morphology with irregular orientation of subcrystal. Compared with crystals separated from traditional hydrogels, crystals growing in the LLC hydrogels were much more regulated and could form aggregates with particular morphology and regular orientation, that is, face (104) of rhombohedral subcrystals parallel to the surface of the macrocrystals. Modification of COOH and SO3H groups made CaCO3 subcrystal align more tightly. COOH had minor influences on the crystal orientation and small modification to the aggregate morphology. SO3H groups could change the crystal orientation and morphology effectively. The aggregates are pseudo‐spherical and the face perpendicularity to the face (104) parallels to the surface of the aggregates.
Preparation of P4VP‐g‐PSt Copolymer Microspheres with Controllable Size by Atom Transfer Radical Polymerization Synthesized Poly(4‐vinylpyridine) Macromonomer
Authors: Hu Na , Ni Zhongbin , Chu Hong , Liu Xiaoya , Chen Mingqing
Published: November 2009

Poly(4‐vinylpyridine) macromonomer (St‐P4VP) with a styryl end group was synthesized by atom transfer radical polymerization (ATRP) of 4‐vinylpyridine using p‐(chloromethyl)styrene (CMSt) as functional initiator, CuCl as catalyst and tris[2‐(dimethylamino)ethyl]amine (Me6TREN) as ligand in 2‐propanol. The structure of St‐P4VP macromonomer was identified by proton nuclear magnetic resonance (1H NMR). The result of gel permeation chromatography (GPC) illustrated that the number‐average molecular weight of St‐P4VP could be controlled by adjusting polymerization conditions. Poly(4‐vinylpyridine) grafted polystyrene microspheres (P4VP‐g‐PSt) were then prepared by dispersion copolymerization of styrene with St‐P4VP macromonomers. The effects of polymerization reaction parameters such as medium polarity, concentration of St‐P4VP macromonomer and polymerization temperature on the sizes and size distribution of P4VP‐g‐PSt microspheres were investigated. The results of transmission electron microscopy (TEM), scanning electron microscopy (SEM) and laser light scattering (LLS) indicated that mono‐dispersed P4VP‐g‐PSt microspheres with average diameters of 100–200 nm could be obtained when the molar ratio of St to St‐P4VP was 0.25:100 in ethanol/water mixed solvents (V/V=80:20) at 60°C. Such kind of graft copolymer microspheres was expected to be applied to many fields such as drug delivery system and protein adsorption/separation system due to their particular structure.
Novel Soluble Polyimide Containing 4‐tert‐Butyltoluene Moiety: Synthesis and Characterization
Authors: Wang Chenyi , Li Guang , Jiang Jianming
Published: November 2009

Based on the synthesis of a rigid aromatic diamine, α,α‐bis(4‐aminophenyl)‐4‐(t‐butyl)toluene (1), a novel polyimide (PI) 3 was prepared from this diamine monomer and 4,4′‐oxydiphthalic dianhydride via a one‐step high‐temperature polycondensation. FT‐IR, 1H NMR and elemental analysis were used to investigate the chemical structures of 1 and 3. The results confirmed that they agreed with the proposed structures for both 1 and 3 completely. The obtained PI 3 showed excellent solubility in most common solvents such as N‐methyl‐2‐pyrrolidinone, N,N‐dimethylacetamide, N,N‐dimethylformamide, chloroform, dichloromethane and tetrahydrofuran. The resulting strong and flexible film exhibited high thermal stability with the glass transition temperature at 317°C and the temperature at 10% weight loss beyond 519°C in both air and nitrogen atmospheres. Moreover, the film also showed high optical transparency, low dielectric constant (3.13 at 1 MHz), low water absorption (0.40%) and hydrophobic character.
PAA‐g‐PVAc Amphiphilic Graft Copolymer Synthesized by Atom Transfer Radical Polymerization
Authors: Zhang Xiaohuan , Wang Beidi , Yang Dong , Zhang Xiaohong , Yuan Li , Tang Qianqian , Hu Jianhua
Published: November 2009

A new amphiphilic graft copolymer containing hydrophilic poly(acrylic acid) backbone and hydrophobic poly(vinyl acetate) side chains was synthesized via sequential atom transfer radical polymerization (ATRP) followed by selective hydrolysis of poly(methoxymethyl acrylate) backbone. Grafting‐from strategy was employed to synthesize PMOMA‐g‐PVAc graft copolymer (Mw/Mn=1.64) via ATRP. The final PAA‐g‐PVAc amphiphilic graft copolymer was obtained by selective acidic hydrolysis of PMOMA backbone in acidic environment without affecting the side chains. The critical micelle concentrations (cmc) in aqueous media were determined by a fluorescence probe technique. The micelle morphologies were found to be spheres.
Synthesis, Crystal Structure, Theoretical Calculation and Thermal Behavior of DNAZ·NTO
Authors: Li Zhaona , Ma Haixia , Yan Biao , Guan Yulei , Song Jirong
Published: November 2009

DNAZ·NTO was prepared by mixing 3,3‐dinitroazetidine (DNAZ) and 3‐nitro‐1,2,4‐triazol‐5‐one (NTO) in ethanol solution. Single crystals suitable for X‐ray measurement were obtained, which belong to monoclinic, space group P21/n with unit cell parameters of a=1.4970(4) nm, b=0.6325(2) nm, c=2.2347(7) nm, β=96.55(1) °, V=2.1022(11) nm3 , Dc=1.752 g·cm−3, F(000) =1136 and Z=8. Based on the analysis of the molecule structure, the theoretical investigation of the title compound was carried out at B3LYP/6‐311++G** levels, and the natural atomic charge and natural bond orbital analysis were performed. The interaction between the cation and anion was also discussed. The thermal behavior of DNAZ·NTO was carried out by DSC and TG/DTG techniques. The apparent activation energy (Ea) and pre‐exponential constant (A) of the main exothermic decomposition reaction were obtained.
Preparation of Barium Titanate Nanopowder through Thermal Decomposition of Peroxide Precursor and Its Formation Mechanism
Authors: Peng Yangxi , Peng Qiyuan , Liu Shijun
Published: November 2009

H2TiO3 was dissolved in the mixture of hydrogen formed peroxide and ammonia under the pH range of 8–10 with a transparent yellow solution formed. When an equivalent mole of Ba2+ solution was added into the yellow solution, the precipitate produced was the peroxide precursor of barium titanate. The cubic nanopowder of barium titanate was obtained when the precipitate was washed, stoved, and then calcined at 600°C for 1 h. The peroxide precursor of barium titanate and barium titanate nanopowder prepared were characterized to be BaTi(H2O2)2O3 by TGA‐DTA, XRD, TEM, SEM, and XREDS. The peroxide precursor of barium titanate was determined to be BaTi(H2O2)2O3. The particle size of the barium titanate nanopowder, the calcined product of BaTi(H2O2)2O3, was in the range of 20–40 nm. A formation mechanism of the barium titanate nanopowder through thermal decomposition of its peroxide precursor was proposed and then validated.
Novel Imatinib Derivatives with Altered Specificity between Bcr–Abl and FMS, KIT, and PDGF Receptors
Authors: Skobridis Konstantinos , Kinigopoulou Maria , Theodorou Vassiliki , Giannousi Emilia , Russell Alison , Chauhan Rakhee , Sala Roberta , Brownlow Nicola , Kiriakidis Serafim , Domin Jan , Tzakos Andreas G. , Dibb Nick J.
Published: November 2009

Imatinib is a clinically important ATP analogue inhibitor that targets the tyrosine kinase domain of the intracellular Abl kinase and the PDGF receptor family. Imatinib has revolutionised the treatment of chronic myeloid leukaemia, which is caused by the oncogene Bcr–Abl and certain solid tumours that harbor oncogenic mutations of the PDGF receptor family. As a leading kinase inhibitor, imatinib also provides an excellent model system to investigate how changes in drug design impact biological activity, which is an important consideration for rational drug design. Herein we report a new series of imatinib derivatives that in general have greater activity against the family of PDGF receptors and poorer activity against Abl, as a result of modifications of the phenyl andN‐methylpiperazine rings. These new compounds provide a platform for further drug development against the therapeutically important PDGF receptor family and they also provide insight into the engineering of drugs with altered biological activity.
Aggressive fibromatosis in children and adolescents
Authors: Meazza Cristina , Bisogno Gianni , Gronchi Alessandro , Fiore Marco , Cecchetto Giovanni , Alaggio Rita , Milano Giuseppe M. , Casanova Michela , Carli Modesto , Ferrari Andrea
Published: November 2009

BACKGROUND:

Aggressive fibromatosis (AF) is a rare tumor of intermediate malignancy that has a strong potential for local invasiveness and recurrence. To date, there are no general recommendations for the clinical management of pediatric AF.

METHODS:

The authors retrospectively analyzed 94 patients aged ≤21 years, including 23 patients who underwent complete surgery (Group I), 42 patients who underwent incomplete surgery with microscopic residual tumor (Group II), and 29 patients who underwent either biopsy or macroscopically incomplete surgery (Group III).

RESULTS:

The 5‐year event‐free survival (EFS) and overall survival rates were 44% and 99%, respectively. Local recurrences developed in 22% of patients in Group I, in 76% of patients in Group II, and in 76% of patients in Group III. Two of 7 patients with abdominal disease died of tumor progression, whereas none of the patients with extra‐abdominal AF died of their disease. Systemic treatment was given to 15 patients as first‐line treatment and to 34 patients at time the time they developed recurrent disease: The response rate was 47% in the former patients and 50% in the latter patients. Objective responses were observed in 11 of 19 patients who received combined methotrexate plus vinblastine/vinorelbine, in 7 of 15 patients who received alkylating‐agent chemotherapy, and in 4 of 11 patients who received other therapies (tamoxifen, sulindac, interferon alfa).

CONCLUSIONS:

The current analysis suggested that the clinical course of AF in children may resemble that of AF in adults. Local recurrences did not affect the chance of responding to systemic therapy or the survival rate. The completeness of initial resection was the main factor that influenced EFS, whereas disease control after marginal resection was much the same as that achieved after intralesional surgery/biopsy. Good responses to systemic treatments, and particularly to low‐dose chemotherapy, were observed as reported previously in adults. Cancer 2010. © 2010 American Cancer Society.
A black‐white comparison of the quality of stage‐specific colon cancer treatment
Authors: Berry Jamillah , Caplan Lee , Davis Sharon , Minor Patrick , Counts‐Spriggs Margaret , Glover Roni , Ogunlade Vickie , Bumpers Kevin , Kauh John , Brawley Otis W. , Flowers Christopher
Published: November 2009

BACKGROUND:

Several studies have attributed racial disparities in cancer incidence and mortality to variances in socioeconomic status and health insurance coverage. However, an Institute of Medicine report found that blacks received lower quality care than whites after controlling for health insurance, income, and disease severity.

METHODS:

To examine the effects of race on colorectal cancer outcomes within a single setting, the authors performed a retrospective cohort study that analyzed the cancer registry, billing, and medical records of 365 university hospital patients (175 blacks and 190 whites) diagnosed with stage II‐IV colon cancer between 2000 and 2005. Racial differences in the quality (effectiveness and timeliness) of stage‐specific colon cancer treatment (colectomy and chemotherapy) were examined after adjusting for socioeconomic status, health insurance coverage, sex, age, and marital status.

RESULTS:

Blacks and whites had similar sociodemographic characteristics, tumor stage and site, quality of care, and health outcomes. Age and diagnostic stage were predictors of quality of care and mortality. Although few patients (5.8%) were uninsured, they were more likely to present at advanced stages (61.9% at stage IV) and die (76.2%) than privately insured and publicly insured patients (p = .002).

CONCLUSIONS:

In a population without racial differences in socioeconomic status or insurance coverage, patients receive the same quality of care, regardless of racial distinction, and have similar health outcomes. Age, diagnostic stage, and health insurance coverage remained independently associated with mortality. Future studies of disparities in colon cancer treatment should examine sociocultural barriers to accessing appropriate care in various healthcare settings. Cancer 2010. © 2009 American Cancer Society.
Variations in gastric cancer care
Authors: Al‐Refaie Waddah B. , Gay Greer , Virnig Beth A. , Tseng Jennifer F. , Stewart Andrew , Vickers Selwyn M. , Tuttle Todd. M. , Feig Barry W.
Published: November 2009

BACKGROUND:

Race is associated with patterns of presentation and survival outcomes of gastric cancer in the United States. However, the impact of race on the receipt of guideline‐recommended care is not well characterized. By using current recommendations, the authors examined the association between race and guideline‐recommended treatments and identified factors that are predictive of variations in gastric cancer care.

METHODS:

By using the National Cancer Database for 1998 through 2005, 106,002 patients with gastric adenocarcinoma were identified. Multivariate analysis techniques were used to examine the association between race, the receipt of guideline‐recommended care, and survival after adjusting for covariates.

RESULTS:

Although African‐American and Hispanic patients were more likely to undergo adequate lymphadenectomy (≥15 lymph nodes) and to receive care at comprehensive cancer centers and high‐volume facilities (for all, P ≤ .001), they were less likely to receive adjuvant multimodality therapy for American Joint Committee on Cancer stage IB through IV, lymph node‐negative (M0) disease. Up to 60% of all patients who underwent gastrectomy failed to receive adequate lymphadenectomy and adjuvant multimodality therapy. The delivery of multimodality therapy varied significantly by stage and lymph node evaluation (P ≤ .001). These findings persisted on our multivariate analyses, indicating that African‐American and Hispanic patients received adequate lymph node evaluation (P ≤ .001), whereas they were associated with receiving no adjuvant multimodality therapy (P ≤ .025).

CONCLUSIONS:

There were significant variations in treatment for gastric cancer among ethnic groups in the United States. It was noteworthy that, although nonwhite race was associated with improved surgical care, gastric cancer care remained suboptimal overall. Cancer programs need to identify procedures to maximize the delivery of adequate gastric cancer care to all patients. Cancer 2010. © 2010 American Cancer Society.
Ending prematurely a weight loss programme: the impact of child and family characteristics
Authors: Braet C. , Jeannin R. , Mels S. , Moens E. , Van Winckel M.
Published: November 2009

The present study evaluates the pre‐treatment child and family characteristics as well as the parental motives and experienced barriers when ending prematurely a weight loss programme for their obese child, in accordance with the ‘barriers‐to‐treatment model’ and subsequent research on dimensions underlying treatment termination decision. Treatment seeking youngsters (n = 72) with a mean of 10.46 years (SD = 2.56) were followed over a 1‐year period. Dropout, child and family characteristics were measured both during assessment and treatment. The ‘barriers‐to‐treatment’ data were collected at the 1‐year follow‐up via mail (response rate = 65%; n = 47). Results showed that dropout could be successfully predicted at intake by age, psychopathology in the child and motivation of the parents. Results indicated further that there are few differences in total barriers score between completers and non‐completers. Item content analysis revealed two themes that were more often reported by non‐completers (appointment arrangements and perceived relevance of treatment). The hypothesis that non‐completers (compared to completers) experienced more barriers that burden their willingness to continue a weight loss programme could not be confirmed. Besides demographic characteristics, specifically motivation of the parents at intake seems an important area for future research. Copyright © 2009 John Wiley & Sons, Ltd.

Key Practitioner Message:

• Families non‐completing a treatment suffer from a greater burden due to psychological problems in their child.

• Regarding the decision to start a treatment, specifically pre‐treatment, motivation and expectations of parents will play a crucial role.

• 47% of the families ended prematurely while their children still suffer from overwight, fueling our assumption that dropping out in treatment is a serious problem and comprises a substantial group of people not studied yet in detail.

• The hypothesis that non‐completers (compared to completers) experienced more barriers that burden their willingness to continue a weight loss program could not be confirmed.
HSG‐ad hocnetwork: A novel hierarchical star graphad hocnetwork with self‐organization and routing discovery free
Authors: Su Tung‐Shih , Jeng Wei‐Lun , Huang Jeng‐Yi , Hsieh Wen‐Shyong
Published: November 2009

Inad hocwireless networks, most data are delivered by multi‐hop routing (hop by hop). This approach may cause long delay and a high routing overhead regardless of which routing protocol is used. To mitigate this inherent characteristic, this work presents a novelad hocnetwork structure that adopts dual‐card‐mode, self‐organization with specific IP naming and channel assignment to form a hierarchical star graphad hocnetwork (HSG‐ad hoc). This network not only expedites data transmission but also eliminates the route discovery procedure during data transmission. Therefore, the overall network reliability and stability are significantly improved. Simulation results show that the proposed approach achieves substantial improvements over DSDV, AODV, and DSR in terms of average end‐to‐end delay, throughput, and packet delivery ratio. Copyright © 2009 John Wiley & Sons, Ltd.
Neue Regelungen für Traggerüste
Authors: Schult Andreas
Published: November 2009

1. Grundlagen der bauaufsichtlichen Behandlung von Gerüsten

2. Traggerüste

3. Nationale Regelungen

4. Europäische Regelungen

5. Anwendungsbeispiele

6. Auswirkungen auf die Praxis
Growth and elongation within and along the axon
Authors: Lamoureux Phillip , Heidemann Steven R. , Martzke Nathan R. , Miller Kyle E.
Published: November 2009

Mechanical tension is a particularly effective stimulus for axonal elongation, but little is known about how it leads to the formation of new axon. To better understand this process, we examined the movement of axonal branch points, beads bound to the axon, and docked mitochondria while monitoring axonal width. We found these markers moved in a pattern that suggests elongation occurs by viscoelastic stretching and volume addition along the axon. To test the coupling between “lengthening” and “growth,” we measured axonal width while forcing axons to grow and then pause by controlling the tension applied to the growth cone or to the cell body. We found axons thinned during high rates of elongation and thickened when the growth cones were stationary. These findings suggest that forces cause lengthening because they stretch the axon and that growth occurs, in a loosely coupled step, by volume addition along the axon. © 2009 Wiley Periodicals, Inc. Develop Neurobiol, 2010