bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of scleraxis and dermo‐1 genes in a regenerating limb of Xenopus laevis
Authors: Satoh Akira , Nakada Yasuaki , Suzuki Makoto , Tamura Koji , Ide Hiroyuki 
Published: February 2006

AbstractXenopus laevis larvae can regenerate an exact replica of the missing part of a limb after amputation at an early limb bud stage. However, this regenerative capacity gradually decreases during metamorphosis, and a froglet is only able to regenerate hypomorphic cartilage, resulting in a spike‐like structure (spike). It has been reported that the spike has tissue deformities, e.g., a muscleless structure. However, our previous study demonstrated that the muscleless feature of the spike can be improved. The existence of other kinds of tissue, such as tendon, has not been clarified. In this study, we focused on the tendon and dermis, and we isolated the scleraxis and dermo‐1 genes, which are known to be marker genes for the tendon and dermis, respectively. The expressions of these genes were investigated in both the developmental and regenerating processes of a Xenopus limb. Although muscle was needed to maintain scleraxis expression, scleraxis transcription was detectable in the muscleless spike. Additionally, although grafting of matured skin, including dermal tissue, inhibited limb regeneration, the expression of dermo‐1, a dermal marker gene, was detected from the early stage of the froglet blastema. These results indicate that tendon precursor cells and dermal cells exist in the regenerating froglet blastema. Our results support the idea that spike formation in postmetamorphic Xenopus limbs is epimorphic regeneration. Developmental Dynamics 235:1065–1073, 2006. © 2006 Wiley‐Liss, Inc.
Practical use of the International Olympic Committee Medical Commission position stand on the female athlete triad: A case example
Authors: Sherman Roberta Trattner , Thompson Ron A. 
Published: February 2006

AbstractThe female athlete triad consists of the interrelated problems of disordered eating, amenorrhea, and osteoporosis, and it is believed to affect female athletes in all sports and at all levels of competition.Objective:The current article highlights the Position Stand on the Female Athlete Triad of the International Olympic Committee's Medical Commission (IOCMC).Method:The literature related to disordered eating, energy availability, amenorrhea, and bone loss in athletes is briefly reviewed. A hypothetical case is presented to illustrate some of the common issues and problems encountered when working with athletes affected by the triad, such as the effect of weight on performance in “thin” sports, coach involvement, sport participation by symptomatic athletes, and treatment resistance/motivation.Results:Strategies recommended by the position stand for managing those issues and problems are presented regarding the referral, evaluation, and treatment phases of the management process.Conclusion:Implications of the position stand are discussed in terms of the IOCMC's endorsement of the athlete's health being primary to her performance. © 2006 by Wiley Periodicals, Inc., Int J Eat Disord, 2006
Spontaneous mutations in the human CMV HLA class I homologue UL18 affect its binding to the inhibitory receptor LIR‐1/ILT2/CD85j
Authors: Cerboni Cristina , Achour Adnane , Wärnmark Anette , Mousavi‐Jazi Mehrdad , Sandalova Tatyana , Hsu Mei‐Ling , Cosman David , Kärre Klas , Carbone Ennio 
Published: February 2006

AbstractHuman cytomegalovirus (HCMV) down‐regulates cell surface expression of HLA class I molecules (HLA‐I). UL18, an HCMV‐encoded HLA‐I homologue, has been proposed to protect virus‐infected cells against NK cell recognition by engaging the inhibitory receptor leukocyte Ig‐like receptor (LIR)‐1, which also binds a broad spectrum of HLA‐I alleles, including HLA‐G1. Because genetic and biological differences exist among HCMV strains, we characterized laboratory (AD169) and clinical (4636, 13B, 109B) strain‐derived UL18 proteins. Compared to the known AD169‐derived UL18, mutations were found in clinical strain‐derived UL18. They were clustered in the α3 domain (13B), previously shown to be critical for LIR‐1 binding, or in the α1 domain (4636). In cytotoxicity assays, pretreatment of LIR‐1+ NKL with soluble 4636‐UL18 completely abolished LIR‐1‐dependent protection from NK lysis, conferred by the expression of HLA‐G1 on target cells (721.221‐HLA‐G1+). Similarly, flow cytometry, Biacore and ELISA experiments showed 4636‐UL18 and 13B‐UL18 to have the strongest binding capacity to LIR‐1. Our results suggest the importance of two independent UL18 regions for LIR‐1 binding, one localized on the tip of the α3 domain, and another composed of two loops that emerge from the α1 domain. Strain variations in these domains may result in different UL18‐mediated effects on LIR‐1+ cells during the course of HCMV infection.
Interactions of Cationic Palladium(II)‐ and Platinum(II)‐η3‐Allyl Complexes with Fluoride: Is Asymmetric Allylic Fluorination a Viable Reaction?
Authors: Hintermann Lukas , Läng Florian , Maire Pascal , Togni Antonio 
Published: February 2006

AbstractThe complex cations [M(η3‐R2All)(PPFPz{3‐tBu})]+ (M = PdII, R2All = 1,3‐diphenylallyl, 1,3‐dicyclohexylallyl, indenyl; M = PtII, R2All = 1,3‐diphenylallyl; PPFPz‐{3‐tBu} = 3‐tert‐butyl‐1‐{1‐[2‐diphenylphosphanyl‐ferrocenyl]ethyl}‐1H‐pyrazole)have been prepared as salts with PF6– or SbF6–. They have been characterized by NMR spectroscopy in solution and by X‐ray crystallography in the solid state. Their reactions with sources of nucleophilic and “naked” fluoride have been investigated by multinuclear NMR spectroscopy. The PdII complexes did not undergo any nucleophilic substitution with concomitant release of allyl fluorides. The dicyclohexylallyl fragment was released as a 1,3‐diene by elimination, but with other allyl complexes nonspecific decomposition reactions predominated. The complex [Pt(η3‐1,3‐Ph2C3H3)(PPFPz{3‐tBu})]PF6 underwent an anion exchange with Me4NF to give [Pt(1,3‐Ph2C3H3)(PPFPz{3‐tBu})]F which existed as a mixture of interconverting allyl isomers in solution at ambient temperature. For the bromide salt, [Pt(η3‐1,3‐Ph2C3H3)(PPFPz{3‐tBu})]Br, allyl isomerization was slow at ambient temperature. Precursors of Pt0 reacted with bromo‐1,3‐diphenylprop‐2‐ene to give [Pt2(μ‐Br)2(η3‐1,3‐Ph2All)2] and precursors of Pd0 underwent oxidative additions with bromo‐ and fluoro‐1,3‐diphenyl‐2‐propene to give 1,3‐diphenylallyl complexes of PdII. Therefore, the nucleophilic attack of fluoride on the allyl fragment of PdII complexes is endergonic, and the high energy barrier of this step is difficult to overcome in a catalytic allylic fluorination reaction. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Mandelohydroxamic Acid as Ligand for Copper(II) 15‐Metallacrown‐5 Lanthanide(III) and Copper(II) 15‐Metallacrown‐5 Uranyl Complexes
Authors: Parac‐Vogt Tatjana N. , Pacco Antoine , Nockemann Peter , Yuan Yao‐Feng , Görller‐Walrand Christiane , Binnemans Koen 
Published: February 2006

AbstractThe formation of pentanuclear copper(II) complexes with the mandelohydroxamic ligand was studied in solution by electrospray ionization mass spectrometry (ESI‐MS), absorption spectrophotometry, circular dichroism and 1H NMR spectroscopy. The presence of lanthanide(III) or uranyl ions is essential for the self‐assembly of the 15‐metallacrown‐5 compounds. The negative mode ESI‐MS spectra of solutions containing copper(II), mandelohydroxamic acid and lanthanide(III) ions (Ln = La, Ce, Nd, Eu, Gd, Dy, Er, Tm, Lu, Y) or uranyl in the ratio 5:5:1 showed only the peaks that could be unambiguously assigned to the following intact molecular ions: {Ln(NO3)2[15‐MC‐5]2–}– and {Ln(NO3)[15‐MC‐5]3–}–, where MHA represents doubly deprotonated mandelohydroxamic acid. The NMR spectra of the pentanuclear species revealed only one set of peaks indicating a fivefold symmetry of the complex. The pentanuclear complexes synthesized with the enantiomerically pure R‐ or S‐forms of mandelohydroxamic acid ligand, showed circular dichroism spectra which were mirror images of each other. The pentanuclear complex made from the racemic form of the ligand showed no signals in the CD spectrum. The UV/Vis titration experiments revealed that the order in which the metal salts are added to the solution of the mandelohydroxamic acid ligand is crucial for the formation of metallacrown complexes. The addition of copper(II) to the solutions containing mandelohydroxamic acid and neodymium(III) in a 5:1 ratio lead to the formation of a pentanuclear complex in solution. In contrary, titration of lanthanide(III) salt to the solution containing copper(II) and mandelohydroxamic acid did not show any evidence for the formation of pentanuclear species. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Metalation Chemistry of meso‐Aryl‐Substituted Expanded Porphyrins
Authors: Shimizu Soji , Osuka Atsuhiro 
Published: February 2006

Abstractmeso‐Aryl‐substituted expanded porphyrins are structural analogues of meso‐aryl‐substituted porphyrins. They exhibit rich and novel coordination behaviors, including multi‐metal chelation due to the large cavities, spin–spin interaction arising from the proximity of metal centers, and large changes in their structural and electrochemical properties upon metalation. The recent discovery of a facile, one‐pot synthesis of a series of meso‐aryl‐substituted expanded porphyrins enables us to investigate their metal‐complexation chemistry. The aim of this Microreview is to highlight recent progress in the synthesis and characterization of metal complexes of meso‐aryl‐substituted expanded porphyrins. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Identification of some rancidity measures at the end of the shelf life of sunflower oil
Authors: Makhoul Hala , Ghaddar Tarek , Toufeili Imad 
Published: February 2006

AbstractSunflower oil was stored at 40 °C, and changes in peroxide value (PV), anisidine value (AnV), thiobarbituric acid (TBA) value, iodine value (IV), conjugated dienes (CD) and hexanal (Hex) levels were monitored. Changes in the odor of samples during storage were assessed sensorially. Apart from IV, which decreased as storage progressed, the other chemical rancidity measures increased. Sensory shelf life data were adequately described by the Weibull distribution, with the 95% confidence interval of the nominal shelf life of sunflower oil, at 40 °C, being 9.04–10.45 wk. The chemical rancidity measures at the end of the sensory shelf life were: PV of 338–352.8 meq peroxide/kg, CD of 1.20–1.24% conjugated dienoic acid, AnV of 21.45–45, TBA values of 23.4–37, and Hex content of 4.79 mg/kg, while IV exhibited a decrease of 8.5–10%. The chemical measures of rancidity marking the end of the sensory shelf life provide objective indices for monitoring the shelf life of sunflower oil.
Deuterium NMR study of the origin of hydrogen in fatty acids produced in vivo by chicken
Authors: Zhang Ben‐Li , Pionnier Sébastien , Buddrus Stephan 
Published: February 2006

AbstractThe origin of hydrogen in fatty acids produced in vivo by chicken was studied by using isotope tracing monitored by 2H NMR. Chickens were fed with deuterium‐labeled water, deuterium‐labeled glucose/fructose and trideuterated acetate. The site‐specific isotope distribution of the fatty acids produced in vivo by the chickens was analyzed after transformation into methyl esters. A connection was observed between the hydrogen atoms of the feeds and water and those of the different molecular positions of the fatty acids produced by chicken. Water hydrogen makes an important contribution to the formation of the lipids. The hydrogen of the enzyme‐bound acetyl or malonyl moiety in acyl‐CoA may be transferred from the C‐1, C‐2 or C‐6 of glucose or fructose and indirectly from water. The hydrogen introduced by the cofactor NADPH may be abstracted from C‐1 and C‐3 of glucose, through its regeneration in the pentose phosphate metabolism pathway, and contains hydrogen atoms of water. The exogenous acetate enters into the in vivo fatty acid biosynthesis pathway in an efficient way and can make an important contribution to the biosynthesis of the lipids.
Cyanodeoxy‐Glycosyl Derivatives as Substrates for Enzymatic Reactions
Authors: Carmona Ana T. , Fialová Pavla , Křen Vladimir , Ettrich Rudiger , Martínková Ludmila , Moreno‐Vargas Antonio J. , González Cristina , Robina Inmaculada 
Published: February 2006

AbstractSynthetic routes for the preparation of new sugar nitriles 8–10 derived from 2‐acetamido‐2‐deoxy‐β‐D‐glucopyranosides bearing a cyano group at the C‐5 or C‐6 position are presented. In an attempt to prepare the glycosyl azide 10 by treatment of tosylate 23 with KCN/DMF at 60 °C, an intramolecular 1,3‐dipolar cycloaddition reaction occurred to give the highly constrained nonisolable tetrazole 24, which was readily converted into the imino‐azido compound 25 through an azido‐tetrazole tautomerism. Compounds 8 and 10 werefound to be poorer substrates of fungal β‐N‐acetylhexosaminidases than compound 9 and none of these compounds was accepted as substrates of the nitrilase or nitrile hydratase. Docking of the nitriles 8–10 in the active site of the β‐N‐acetylhexosaminidase from Aspergillus oryzae gave interaction energies comparable with the natural substrate. Based on these data, which indicate strong binding of these compounds (8 > 9 > 10) to the active site, it has been proposed that some cyano derivatives may act as competitive inhibitors of β‐N‐acetylhexosaminidases. This hypothesis is consistent with enzyme inhibition experiments which showed strong inhibitory properties of compound 9 (KI = 0.37 mM) and in particular of compound 8 (KI = 7.6 μM). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Nitrogen Functionalities in Palladium‐Catalyzed Reactions on Solid Supports: A Case Study
Authors: Knepper Kerstin , Vanderheiden Sylvia , Bräse Stefan 
Published: February 2006

AbstractThree different Palladium‐catalyzed reactions (Heck, Suzuki, Sonogashira) were carried out on three different types of linkers on solid supports. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
syn‐ and anti‐Isomers of a O‐Methyloxime‐Substituted Tricyclic Ozonide
Authors: Griesbaum Karl , Frank Achim , McCullough Kevin J. 
Published: February 2006

AbstractThe ozonolysis of bicyclo[9.4.0]pentadec‐1(11)‐en‐12‐one (4) in pentane, followed by the treatment of the ozonolysisproduct with O‐methylhydroxylamine afforded the stable ozonides anti‐(8) and syn‐2‐O‐methyloxime‐16,17,18‐trioxatricyclo[10.3.2.1]octadecane (9). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Crucial Role of the Conjugate Base for Silyl Lewis Acid Induced Mukaiyama Aldol Reactions
Authors: Hiraiwa Yukihiro , Ishihara Kazuaki , Yamamoto Hisashi 
Published: February 2006

AbstractThe silyl Lewis acid induced Mukaiyama aldol reaction proceeds through each catalytic cycle under the influence of their conjugate bases; there is an especially significant difference between the low nucleophilic conjugate bases, –NTf2 and –CTf3, and the relatively high nucleophilic –OTf. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Lewis Acid Catalyzed Conjugate Addition and the Formation of Heterocycles using Michael Acceptors under Solvent‐Free Conditions
Authors: Mekonnen Alemayehu , Carlson Rolf 
Published: February 2006

AbstractConjugate addition and conjugate‐addition‐initiated ring closure (CAIRC) reactions of β‐dicarbonyl compounds with Michael acceptors have been studied using several Lewis acid catalysts under solvent‐free conditions. Excellent chemoselectivity was obtained when various Michael acceptors were treated with several β‐dicarbonyl compounds. On the other hand, 2‐bromo‐2‐cyclopentenone and 3‐bromo‐3‐vinyl methyl ketone furnished 2,3‐dihydrofurans instead of the 1,4‐adducts when treated with the same reagents.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Strategies for the Formation of Tetrahydropyran Rings in the Synthesis of Natural Products
Authors: Clarke Paul A. , Santos Soraia 
Published: February 2006

AbstractThis microreview surveys the literature over the last five years with regard to construction of functionalised tetrahydropyran (THP) rings in the context of the synthesis of natural products. The overview given is intended to provide a working knowledge of the area for those who are unfamiliar, and to refresh and remind those who do work in the area of the exciting developments in the field. While the construction of the THP rings in a number of natural products has been reviewed, we have attempted to highlight the different strategies by focusing on two natural products, namely phorboxazole and centrolobine as case studies. Over the last five years, these natural products have become a test bed for new methods for the construction of THP rings. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Synthesis of An Enantioenriched C2‐Symmetric Molecule by a Chiral‐Base‐Mediated Kinetic Resolution of an (Arene)tricarbonylchromium(0) Complex
Authors: Castaldi M. Paola , Gibson Susan E. , White Andrew J. P. 
Published: February 2006

AbstractTrimethylsilyl substituents have been used to control the conformational preferences of a 1,2‐disubstituted (arene)tricarbonylchromium(0) complex. The kinetic resolution of the mono‐methyl derivative (±)‐11 using a chiral base/iodomethane quench sequence led to the synthesis of the enantioenriched C2‐symmetric bis‐ether (+)‐13. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Highlighting the role of the chlorine substituents in the glycopeptide antibiotic balhimycin for chiral recognition in capillary electrophoresis
Authors: Jiang Zhengjin , Bertazzo Marcelo , Süssmuth Roderich D. , Yang Zhuohong , Smith Norman Williams , Schurig Volker 
Published: February 2006

AbstractThe vancomycin‐type glycopeptide antibiotic balhimycin (I) and its dehaloanalogue dechlorobalhimycin (III), which is characterized by the total substitution of the two chlorine atoms of I by hydrogen, were employed as chiral selectors for the enantioresolution of 11 racemic dansyl amino acids and six 2‐arylpropionic acid nonsteroidal anti‐inflammatory racemic drugs by CE. The observed enantioresolution capability of I for all test analytes is clearly higher than that observed for III. This result suggests that chlorine substituents of I played a major role in the enantioresolution of these test analytes. A dimerization‐based mechanism is proposed in order to explain this phenomenon. The two chlorine substituents of each monomer, which mutually penetrate into the cavity of the adjacent molecule of the dimer, are assumed to promote dimerization and as a consequence also enantioresolution.
Less common applications of monoliths: I. Microscale protein mapping with proteolytic enzymes immobilized on monolithic supports
Authors: Svec Frantisek 
Published: February 2006

AbstractThis review summarizes the recent contributions to the rapidly growing area of immobilized enzymes employing both silica and synthetic polymer‐based monoliths as supports. Focus is mainly on immobilized proteolytic enzyme reactors designed for studies in proteomics. Porous monoliths emerged first as a new class of stationary phases for HPLC in the early 1990s. Soon thereafter, they were also used as supports for immobilization of proteins and preparation of both stationary phases for bioaffinity chromatography and enzymatic reactors. Organic polymer‐based monoliths are typically prepared using a simple molding process carried out within the confines of a “mold” such as chromatographic column or capillary. Polymerization of a mixture comprising monomers, initiator, and porogenic solvent affords macroporous materials. In contrast, silica‐based monoliths are first formed as a rigid rod from tetraalkoxysilane in the presence of PEG and subsequently encased with a plastic tube. Both types of monolith feature large through‐pores that enable a rapid flow‐through. Since all the solutions must flow through the monolith, the convection considerably accelerates mass transfer within the monolith. As a result, reactors including enzyme immobilized on monolithic support exhibit much higher activity compared to the reactions in solution.
Spatial modelling using a new class of nonstationary covariance functions
Authors: Paciorek Christopher J. , Schervish Mark J. 
Published: February 2006

AbstractWe introduce a new class of nonstationary covariance functions for spatial modelling. Nonstationary covariance functions allow the model to adapt to spatial surfaces whose variability changes with location. The class includes a nonstationary version of the Matérn stationary covariance, in which the differentiability of the spatial surface is controlled by a parameter, freeing one from fixing the differentiability in advance. The class allows one to knit together local covariance parameters into a valid global nonstationary covariance, regardless of how the local covariance structure is estimated. We employ this new nonstationary covariance in a fully Bayesian model in which the unknown spatial process has a Gaussian process (GP) prior distribution with a nonstationary covariance function from the class. We model the nonstationary structure in a computationally efficient way that creates nearly stationary local behaviour and for which stationarity is a special case. We also suggest non‐Bayesian approaches to nonstationary kriging.To assess the method, we use real climate data to compare the Bayesian nonstationary GP model with a Bayesian stationary GP model, various standard spatial smoothing approaches, and nonstationary models that can adapt to function heterogeneity. The GP models outperform the competitors, but while the nonstationary GP gives qualitatively more sensible results, it shows little advantage over the stationary GP on held‐out data, illustrating the difficulty in fitting complicated spatial data. Copyright © 2006 John Wiley & Sons, Ltd.
Adaptive measurement‐based traffic engineering in small differentiated services domains
Authors: Krasser Sven , Owen Henry , Sokol Joachim , Grimminger Jochen , Huth Hans‐Peter 
Published: February 2006

AbstractIn this paper, we propose a framework for measurement‐based traffic engineering and connection admission control in small‐differentiated services domains. The domain investigated is a wired radio access network based on the Internet protocol (IP). This framework is evaluated by simulation using the popular network simulator ns‐2. The framework is adaptive to changes in the network load and supports multiple types of service. All traffic‐engineering decisions are made by edge routers (ERs) at the rim of the network domain. Multiple disjoint paths are configured between those ERs. Network state information is gathered in two different fashions. We evaluate a scheme based on the states of the queues on each alternative path and a scheme based on end‐to‐end probe packet transmission characteristics on each alternative path. Both schemes are compared to a shortest path first (SPF) routing approach. Copyright © 2006 AEIT