bluuebunny/crossref_metadata_2025_split huggingface dataset:
Toward Carbohydrate Derivatives with a Markedly Acidic Centre: Structures and Reactions of Selenium(IV) Diolates
Authors: Klüfers Peter , Reichvilser Moritz M. 
Published: November 2007

AbstractCyclic selenites, of the general formula (DiolH–2)SeO, derived from the diols ethane‐1,2‐diol, propane‐1,2‐diol, cis‐cyclopentane‐1,2‐diol, cis‐cyclohexane‐1,2‐diol, trans‐cyclohexane‐1,2‐diol, 1,1′‐bicyclopentyl‐1,1′‐diol, 1,1′‐bicyclohexyl‐1,1′‐diol, propane‐1,3‐diol, 2,2‐dimethylpropane‐1,3‐diol, 1,1‐bis(hydroxymethyl)cyclopropane, 1,1‐bis(hydroxymethyl)cyclopentane, 1,4‐anhydroerythritol and the methyl glycosides of β‐D‐ribofuranose, β‐D‐ribopyranose, α‐D‐mannopyranose, β‐D‐xylopyranose have been prepared and characterised by multinuclear NMR spectroscopy and single‐crystal X‐ray diffraction. Even with the polyfunctional sugar derivatives, oxidation of substrates did not occur. It has been demonstrated that the title compounds are hydrolytically stable at low pH values. Experimental NMR spectroscopy and structural data are consistent with results of density functional calculations and bonding has been analysed by means of natural bond orbital (NBO) theory.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Formation and Characterization of Platinum and Palladium Complexes of Bis(trimethylsilylmethyl)tellane
Authors: Vigo Ludmila , Oilunkaniemi Raija , Laitinen Risto S. 
Published: November 2007

AbstractThe mononuclear (telluroether)platinum and ‐palladium complexes cis‐[PtCl2{Te(CH2SiMe3)2}2] (2c), trans‐[PtCl2{Te(CH2SiMe3)2}2] (2t), and trans‐[PdCl2{Te(CH2SiMe3)2}2] (3t) have been prepared from bis(trimethylsilylmethyl)tellane and bis(benzonitrile)dichloridoplatinum and ‐palladium and structurally characterized by single‐crystal X‐ray diffraction and NMR spectroscopy. The isomer distribution of the platinum complex depends on the initial molar ratio of the reactants. When [PtCl2(NCPh)2] was used in excess, 2c was the main product. Upon increasing the initial ligand/metal molar ratio, the relative amount of 2t increased. The stoichiometric reaction afforded approximately equal amounts of the cis and trans isomers. Further increase of the initial amount of the ligand yielded 2t. The mononuclear palladium complex was the trans isomer 3t, regardless of the initial molar ratio of the reactants. Small amounts of the dinuclear complex [Pt2Cl4{μ‐Te(CH2SiMe3)2}{Te(CH2SiMe3)2}2] (4) were also formed, when the initial ligand/metal molar ratio was low. Compound 4 shows a rare bridging telluroether ligand and two different platinum coordination environments, one exhibiting a cis‐Cl/cis‐TeR2 arrangement and the other a trans‐Cl/trans‐TeR2 arrangement. In case of palladium, the equimolar reaction afforded [Pd2(μ‐Cl)2Cl2{Te(CH2SiMe3)2}2] (5) in good yields. As the relative amount of the ligand was increased, also 3t was formed. When the ligand/metal ratio was >2:1, 3t was the only product. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Optical, Magnetic and Structural Properties of the Spin‐Crossover Complex [Fe(btr)2(NCS)2]·H2O in the Light‐Induced and Thermally Quenched Metastable States
Authors: Legrand Vincent , Pillet Sébastien , Carbonera Chiara , Souhassou Mohamed , Létard Jean‐François , Guionneau Philippe , Lecomte Claude 
Published: November 2007

Abstract[Fe(btr)2(NCS)2]·H2O [btr = 4,4′‐bis(1,2,4‐triazole)] is thearchetype of highly cooperative and low‐dimensional spin‐crossover complexes, which exhibit low‐spin (LS) to high‐spin (HS) light‐induced conversion at very low temperature. The structural reorganizations related to the light‐induced and thermally induced LS–HS transitions were characterized by single‐crystal X‐ray diffraction below the relaxation temperature (T = 15 K < TLIESST) and at 130 K within the thermal hysteresis loop. We show that the LIESST and thermal spin transitions lead to the same structural variations, namely an elongation of the Fe–N bonds by 0.18 Å (Fe–NNCS) and 0.20 Å (Fe–Nbtr), on going from LS to HS, together with a reorientation of the NCS group by nearly 13°. The atomic displacement amplitudes, derived from the crystal structures, indicate lattice vibration modes of larger amplitudes and correlatively lower vibration frequencies in the HS state. The deformation of the crystal lattice as a function of temperature and laser excitation was quantitatively analyzed in terms of the HS and LS thermal‐expansion (αHS and αLS) and spin‐transition spontaneous‐strain (ϵ) tensors. The eigendirections and eigenvalues of the α and ϵ tensors correlate well with the weak and strong interactions in the solid and are responsible for the high cooperativity and low‐dimensional behaviour. Magnetic and spectroscopic measurements were performed in all the different spin states and related to the structural findings. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Heterocycle‐Substituted Indenes as Precursors for Supported Zirconocene Catalysts
Authors: Aragón Sáez Pedro J. , Carrillo‐Hermosilla Fernando , Villaseñor Elena , Otero Antonio , Antiñolo Antonio , Rodríguez Ana M. 
Published: November 2007

AbstractThe indene ligands {1‐C9H7R} [R = C2H4(C4H7O2) (1), C2H4(C3H5O2) (2), CH2(C5H9O) (3)] were prepared by alkylation of indene and used to prepare the SiMe2‐bridged indenylcyclopentadiene ligands {Me2Si(3‐C9H6R)(C5Me4H)}[R = C2H4(C4H7O2) (4), CH2(C5H9O) (5)]. Bis(indenyl)‐and ansa‐indenylcyclopentadienyl zirconocenes [Zr{1‐η5‐C9H6R}2Cl2] {R = C2H4(C4H7O2) (6), C2H4(C3H5O2) (7), CH2(C5H9O) (8)} and [Zr{Me2Si(3‐η5‐C9H5R)(η5‐C5Me4)}Cl2] {R = C2H4(C4H7O2) (9), CH2(C5H9O) (10)} were prepared by the reaction of ZrCl4 with the appropriate mono‐ or dilithium salts of 1–5. The molecular structure of [Zr{Me2Si(3‐η5‐C9H5C2H4(C4H7O2))(η5‐C5Me4)}Cl2] (9) was determined by single‐crystal X‐ray diffraction studies. Indenylzirconium complexes 6–10 were immobilized on thf‐modified MgCl2, and these supported systems were used to polymerize ethylene in the presence of methylaluminoxane. The catalytic activity of these complexes in both homogeneous and supported polymerization reactions is discussed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
The First Linear Coordination Oligomer Linked by 4,4′‐Bipyridine
Authors: Wang Yutian , Englert Ulli 
Published: November 2007

AbstractA unique coordination oligomer derived from bridging 4,4′‐bipyridine (bipy) ligands was synthesized and characterized. Long linear [Ag4(bipy)5]4+ tetracations, shorter [Ag2(bipy)3]2+ dications and 4‐aminobenzoate anions represent the major constituents. When silver nitrate was added to solutions of this salt, polymerization in high yield occurred. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
(η5‐Cyclopentadienyl)(η4‐tetrasila‐ and η4‐trisilagermacyclobutadiene)cobalt: Sandwich Complexes Featuring Heavy Cyclobutadiene Ligands
Authors: Takanashi Kazunori , Lee Vladimir Ya. , Ichinohe Masaaki , Sekiguchi Akira 
Published: November 2007

Abstract(η5‐Cyclopentadienyl)(η4‐tetrasilacyclobutadiene)cobalt{[(η4‐R4Si4)CoCp], 2} and (η5‐cyclopentadienyl)(η4‐trisilagermacyclobutadiene)cobalt {[(η4‐R4Si3Ge)CoCp], 4} (R = SiMetBu2) were synthesized by reaction of the dipotassium salts of tetrasilacyclobutadiene dianion K+2·[R4Si4]2– (1) and trisilagermacyclobutadiene dianion K+2·[R4Si3Ge]2– (3) with [CpCoI2(PPh3)]. Alternatively, 4 was prepared by the reaction of 3 with [Cp2Co]+·[PF6]–. X‐ray crystallographic analysis of 2 confirmed its sandwich‐type structure, manifesting a nearly square‐planar Si4 ring and diagnostic perhaptocoordination of both ligands, η4‐tetrasilacyclobutadiene and η5‐cyclopentadienyl, to the Co atom. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Reconstruction of shape and its effect on flow in arterial conduits
Authors: Gambaruto A. M. , Peiró J. , Doorly Denis J. , Radaelli A. G. 
Published: November 2007

AbstractThe geometry of arterial conduits derived fromin vivoimage data is subject to acquisition and reconstruction errors. This results in a degree of uncertainty in defining the bounding geometry for a patient‐specific anatomical conduit. In applying computational fluid dynamics to model the flow in specific anatomical configurations, the effect of the uncertainty in boundary definition should be considered, particularly if the objective is to extract quantitative measures of the local haemodynamics.Taking an example of a bypass graft configuration, we examine the effects of image threshold, surface smoothing and semi‐idealization on the modelled geometry and the resulting flow. Procedures for reconstruction from medical images are outlined and applied with different parameter values within the image uncertainty range to create alternative models from the same data set.Methods to characterize the flow structure and wall shear stress (WSS) are introduced and used to provide quantitative comparison of the different haemodynamic environments associated with the varying model geometries. Comparable effects on the WSS distribution are found to occur with progressively increased surface smoothing and semi‐idealization of the geometry by elliptical section fitting. Significant differences in WSS correspond to different threshold choices. Copyright © 2007 John Wiley & Sons, Ltd.
Geological evolution and structural style of the Palaeozoic Tafilalt sub‐basin, eastern Anti‐Atlas (Morocco, North Africa)
Authors: Toto E. A. , Kaabouben F. , Zouhri L. , Belarbi M. , Benammi M. , Hafid M. , Boutib L. 
Published: November 2007

AbstractThe Tafilalt is one of a number of generally unexplored sub‐basins in the eastern Anti‐Atlas of Morocco, all of which probably underwent a similar tectono‐stratigraphic evolution during the Palaeozoic Era. Analysis of over 1000 km of 2‐D seismic reflection profiles, with the interpretation of ten regional seismic sections and five isopach and isobath maps, suggests a multi‐phase deformation history for the Palaeozoic‐aged Tafilalt sub‐basins. Extensional phases were probably initiated in the Cambrian, followed by uniform thermal subsidence up to at least the end of the Silurian. Major extension and subsidence did not begin prior to Middle/Upper Devonian times. Extensional movements on the major faults bounding the basin to the north and to the south took place in synchronisation with Upper Devonian sedimentation, which provides the thickest part of the sedimentary sequence in the basin. The onset of the compressional phase in Carboniferous times is indicated by reflectors in the Carboniferous sequence progressively onlapping onto the Upper Devonian sequence. This period of compression developed folds and faults in the Upper Palaeozoic‐aged strata, producing a structural style characteristic of thin‐skinned fold and thrust belts. The Late Palaeozoic units are detached over a regional décollement with a northward tectonic vergence. The folds have been formed by the process of fault‐propagation folding related to the thrust imbricates that ramp up‐section from the décollement. Copyright © 2007 John Wiley & Sons, Ltd.
Ultrastructure of Trypanosoma cruzi revisited by atomic force microscopy
Authors: Rocha Gustavo Miranda , Miranda Kildare , Weissmüller Gilberto , Bisch Paulo Mascarello , de Souza Wanderley 
Published: November 2007

AbstractMost advances in atomic force microscopy (AFM) have been accomplished in recent years. Previous attempts to use AFM to analyze the organization of pathogenic protozoa did not significantly contribute with new structural information. In this work, we introduce a new perspective to the study of the ultrastructure of the epimastigote form of Trypanosoma cruzi by AFM. Images were compared with those obtained using field emission scanning electron microscopy of critical point dried cells and transmission electron microscopy of negative stained detergent‐extracted and air‐dried cells. AFM images of epimastigote forms showed a flagellum furrow separating the axoneme from the paraflagellar rod (PFR) present from the emergence of the flagellar pocket to the tip of the flagellum. At high magnification, a row of periodically organized structures, which probably correspond to the link between the axoneme, the PFR and the flagellar membrane were seen along the furrow. In the origin of the flagellum, two basal bodies were identified. Beyond the basal bodies, small periodically arranged protrusions, positioned at 400 nm from the flagellar basis were seen. This structure was formed by nine substructures distributed around the flagellar circumference and may correspond to the flagellar necklace. Altogether, our results demonstrate the importance of the application of AFM in the structural characterization of the surface components and cytoskeleton on protozoan parasites. Microsc. Res. Tech., 2008. © 2007 Wiley‐Liss, Inc.
Mapping the intake of different elements in vegetal tissues by dual‐energy X‐ray imaging at DaΦne synchrotron light source
Authors: Reale L. , Kaiser J. , Reale A. , Lai A. , Flora F. , Balerna A. , Cinque G. , Fanelli M. , Ruggieri F. , Faenov A. , Pikuz T. , Tucci A. , Poma A. , Zuppella P. , Liška M. , Malina R. 
Published: November 2007

AbstractThis article reports on the first utilization of the soft X‐ray beamline at the DaΦne synchrotron light source for mapping the intake of different elements in plant tissues. As a test, the method of dual‐energy X‐ray microradiography was applied to the investigation of the natural sulfur content in dried leaf and root samples. Our ultimate goal was to monitor the pollutant lead and its intake, which was added in controlled doses to the hydroponic medium of laboratory‐controlled samples of vegetal species. The results obtained by the nondestructive X‐ray radiographic analysis are compared to the values of concentrations determined by a standard chemical analysis utilizing atomic absorption spectroscopy. From this comparison the validity of the X‐ray detection of heavy metals in biological samples has been confirmed. The superposition of the dual energy results on the simple planar radiography shows the representation of the pollutant intake directly on the sample structures. It should be pointed out that this method, developed here for plant root and leaves could be applied to any biological sample of interest, but the preparation and observation conditions necessitate different strategies according to the type of sample under analysis. Microsc. Res. Tech., 2008. © 2007 Wiley‐Liss, Inc.
Post‐embryonic development of the antennal sensilla inMelipona quadrifasciata anthidioides(Hymenoptera: Meliponini)
Authors: Azevedo Dihego de Oliveira , Matiello‐Guss Cirlei Pereira , Rönnau Milton , Zanuncio José Cola , Serrão José Eduardo 
Published: November 2007

AbstractThe sensilla are sensory organs formed by cuticular and cellular structures specialized in reception of chemical and physical stimuli from the environment and transmission to the insect's central nervous system. In function of the great concentration of sensilla, the antennae are the main organs for interaction between bees and with the environment. This work studied the presence of antennal sensilla in the different phases of pupal development of the stingless beeMelipona quadrifasciata anthidioidesby means of scanning electron microscopy and light microscopy. The results showed that antennal sensilla begin their development in the transition of the prepupae to the white‐eyed pupae and finish it in the pigmented‐body pupae phase. The antennal sensilla were exposed to the environment in the black‐eyed pupae when the old cuticle is completely digested, suggesting that only in the final pupal phases can these bees perceive the environmental stimuli. Microsc. Res. Tech., 2008. © 2007 Wiley‐Liss, Inc.
Ultrastructural study on the body surface of the acanthocephalan parasite Dentitruncus truttae in brown trout
Authors: Dezfuli Bahram S. , Lui Alice , Giari Luisa , Boldrini Paola , Giovinazzo Giancarlo 
Published: November 2007

AbstractScanning electron microscope (SEM) investigations on the holdfast elements, proboscis hooks, and trunk spines of Dentitruncus truttae (Acanthocephala, Palaeacanthocephala), an endoparasite of Salmo trutta (brown trout), provide more data about the surface of these taxonomic relevant structures. In both acanthocephalan sexes, the fully everted cylindrical proboscis possessed 18 longitudinal rows of hooks with 18 hooks per row (rarely 19–20). Hook length varied according to position on the proboscis; apical hooks were 40–52 μm long, middle hooks were 31.7–36.6 μm, and basal hooks were 38.1–40 μm. Starting from the anterior end of the metasoma, numerous cuticular spines (26.7–30 μm in length) were visible and their number progressively decreased posteriorly. SEM observations of D. truttae hooks and spines revealed the presence of many surface striations on each proboscis hook. These surface striations were absent from trunk spines. From the base of the hook, the striations ran parallel toward the point of convergence. Additionally, survey of longitudinal and transversal sections of the hook using transmission electron microscope confirmed that the hook surface was not smooth. SEM comparison with the hooks of several palaeacanthocephalan species, as well as with the hooks of species belonging to Eoacanthocephala and Polyacanthocephala, indicated that the striations are currently exclusive to D. truttae proboscis hooks. Microsc. Res. Tech., 2008. © 2007 Wiley‐Liss, Inc.
A morphometric analysis of tunnel valleys in the eastern North Sea based on 3D seismic data
Authors: Kristensen Thomas B. , Huuse Mads , Piotrowski Jan A. , Clausen Ole R. 
Published: November 2007

AbstractA 1250 km2 3D seismic volume is used to provide a detailed spatial and geometrical analysis of fifteen Pleistocene tunnel valleys in the Danish North Sea. All the valleys are buried; they are up to 39 km long, 3–4 km wide and up to 350 m deep. The valleys are part of a vast tunnel valley province covering an area of some 0.5 million km2 of the formerly glaciated lowland areas of North West Europe. The valleys consist of non‐branching, non‐anastomosing troughs; they exhibit strongly undulating bottom profiles with numerous sub‐basins and thresholds, and are characterised by adverse end slopes. Cross‐cutting relationships and theoretical considerations suggest the occurrence of seven major episodes of valley incision attributed to ice marginal oscillations within a few glacials. Calculations considering the valley end gradients and theoretical ice‐surface profiles suggest that the valleys were formed by pressurised subglacial meltwater erosion. Given a range of theoretical ice‐surface profiles, the adverse end slopes are well beyond the supercooling threshold, which suggests that the water was not in thermal equilibrium with the basal ice and that flow was concentrated in substantial conduits with sufficient mass and flux to maintain water temperature well above the freezing point. Copyright © 2007 John Wiley & Sons, Ltd.
Effects of particle size reduction of insoluble fibres by micron technology on various caecal and faecal indices
Authors: Huang Ya‐Ling , Sheu Fuu , Lee Mao‐Hsiang , Chau Chi‐Fai 
Published: November 2007

AbstractBACKGROUND: Previous findings demonstrated that particle size reduction of insoluble fibre materials (i.e. starfruit insoluble fibre‐rich fraction and cellulose) to micro‐sizes effectively enhanced their physicochemical properties, which provided clues to their physiological functions. The aim of the present study was to investigate the effects of particle size reduction of these insoluble fibres by micron technology on indices of bowel health.RESULTS: Feeding of the micronised fibres (9.68–14.3 µm), especially those prepared by high‐pressure micronisation, effectively (P < 0.05) improved various caecal and faecal indices, such as decreasing the caecal ammonia concentration (by 20.0–30.0%), increasing the faecal output (135–150%) and moisture content (143–157%) and lowering the activities of undesired β‐D‐glucosidase (by 39.2–43.6%) and β‐D‐glucuronidase (by 71.4–77.5%) in faeces of hamsters. Relationships between physicochemical properties and physiological functions of the micronised fibres were considered. The results also demonstrated that the type, processing and related particle size of insoluble fibres were important factors affecting their physicochemical properties and physiological functions.CONCLUSION: The consumption of micronised insoluble fibres at 5% level might exert a favourable effect on improving various caecal and faecal indices. The results of this study provide some hints on potential applications of micron technology in the food industry. Copyright © 2007 Society of Chemical Industry
Effect of O2 scavenger on the shelf‐life of catfish (Pangasius sutchi) steaks during chilled storage
Authors: Mohan Chitradurga O , Ravishankar Chandragiri N , Srinivasagopal Teralandur K 
Published: November 2007

AbstractBACKGROUND: Active packaging for preserving meat products, including seafoods, has been gaining importance in recent times. The present study was undertaken to assess the effectiveness of O2 scavenger, the most widely used active packaging technology, on the shelf‐life of catfish steaks in chilled storage conditions.RESULTS: O2 scavenger was effective in reducing the oxygen concentration inside the packaging to as low as 0.42% within 24 h. This reduction in oxygen in O2 scavenger packages showed positive effects on quality parameters compared to control air packs. Total volatile base nitrogen (TVB‐N), thiobarbituric acid value and peroxide value of catfish steaks packed in O2 scavenger was significantly different (P < 0.05) compared to air‐packed samples. Based on the sensory, microbiological and TVB‐N values, the control samples were acceptable only up to 10 days, compared to 20 days in O2 scavenger‐packed samples, extending the shelf‐life by 10 days.CONCLUSION:O2 scavenger reduced the oxygen concentration inside the package significantly within 24 h compared to control air packs. By using this technique, the use of a vacuum packing machine can be avoided. Further, O2 scavenger extended the product's shelf‐life up to 20 days, compared to 10 days in control packs. Copyright © 2007 Society of Chemical Industry
Influence of a severe reduction of the feeding level during the period immediately prior to free‐range fattening on performance and fat quality in Iberian pigs
Authors: Daza Argimiro , Lopez‐Bote Clemente J , Olivares Alvaro , Menoyo David , Ruiz Jorge 
Published: November 2007

AbstractBACKGROUND: Restricted feeding before fattening is a common procedure in the production of Iberian pigs, but little scientific information about its consequences on productive traits and characteristics of fat is available. This work studied the effect of a severe feeding restriction previous to the free‐range fattening on carcass and fat quality traits in Iberian pigs, considering two different feeding levels (high restriction: HR; versus maintenance level: M) before free‐range fattening.RESULTS: Animals from the M group showed longer and higher‐perimeter hams and tended (P < 0.10) to show higher slaughter and carcass weights, carcass inner length and loin and sirloin weights than HR ones. Animals from the HR group showed lower proportions of total saturated fatty acids (SFA) and higher total monounsaturated fatty acids in the backfat inner layer than those from the M group. Total polyunsaturated fatty acids in intramuscular neutral lipids were higher in HR pigs than in M ones, while stearic acid (C18:0) was lower. The average daily gain, fatty acid profile of the outer backfat layer and that of the hepatic polar and neutral lipids and the rheological features of backfat inner layer remained unaffected.CONCLUSION: A severe reduction of the feeding level previous to free‐range fattening does not produce compensatory growth, tends to diminish carcass quality and to slightly increase IMF content and improves the fatty acid profile of the inner backfat layer. Copyright © 2007 Society of Chemical Industry