bluuebunny/crossref_metadata_2025_split huggingface dataset:
Uptake and biotransformation of 2,4,6‐trinitrotoluene (TNT) by microplantlet suspension culture of the marine red macroalga Portieria hornemannii
Authors: Cruz‐Uribe Octavio , Rorrer Gregory L. 
Published: September 2005

AbstractMicroplantlets of the marine red macroalga Portieria hornemannii efficiently removed the explosive compound 2,4,6‐trinitrotoluene (TNT) from seawater. Photosynthetic, axenic microplantlets (1.2 g FW/L) were challenged with enriched seawater medium containing dissolved TNT at concentrations of 1.0, 10, and 50 mg/L. At 22°C and initial TNT concentrations of 10 mg/L or less, TNT removal from seawater was 100% within 72 h, and the first‐order rate constant for TNT removal ranged from 0.025 to 0.037 L/gFW h under both illuminated conditions (153 µE/m2s, 14:10 LD photoperiod) and dark conditions. Two immediate products of TNT biotransformation, 2‐amino‐4,6‐dinitrotoluene and 4‐amino‐2,6‐dintrotoluene, were identified in the liquid culture medium, with a maximum material balance recovery of 29 mole%. Only trace levels of these products and residual TNT were found within the fresh cell biomass. Removal of TNT by P. hornemannii microplantlets at initial concentrations of 1.0 or 10 mg/L did not affect the respiration rate. At an initial TNT concentration of 10 mg/L, net photosynthesis decreased towards zero, commensurate with the removal of dissolved TNT from seawater, whereas at an initial TNT concentration of 1.0 mg/L, the net photosynthesis rate was not affected. © 2005 Wiley Periodicals, Inc.
Initial transcriptome and proteome analyses of low culture temperature‐induced expression in CHO cells producing erythropoietin
Authors: Baik Jong Youn , Lee Moon Sue , An So Ra , Yoon Sung Kwan , Joo Eun Jin , Kim Young Hwan , Park Hong Woo , Lee Gyun Min 
Published: September 2005

AbstractLow culture temperature is known to enhance the specific productivity of Chinese hamster ovary (CHO) cells expressing erythropoietin (EPO) (LGE10‐9‐27). Genomic and proteomic approaches were taken to better understand the intracellular responses of these CHO cells resulting from use of low culture temperature (33°C). For transcriptome analysis, commercially available rat and mouse cDNA microarrays were used. The data obtained from the rat and mouse cDNA chips were only somewhat informative in understanding the gene expression profile of CHO cells because of their different sequence homologies with CHO transcriptomes. Overall, transcriptome analysis revealed that low culture temperature could lead to changes in gene expression in various cellular processes such as metabolism, transport, and signaling pathways. Proteome analysis was carried out using 2‐D PAGE. Based on spot intensity, 60 high intensity protein spots, from a total of more than 800, were chosen for MS analysis. Forty of the 60 protein spots, which represent 26 different kinds of proteins, were identified by MALDI‐TOF‐MS and validated by MS/MS. Compared to the reference temperature (37°C), the expression levels of seven proteins (PDI, vimentin, NDK B, ERp57, RIKEN cDNA, phosphoglycerate kinase, and heat shock cognate 71 kDa protein) were increased over twofold at 33°C and those of two proteins (HSP90‐beta and EF2) were decreased over twofold at 33°C. Taken together, the results demonstrate the potential of combined analysis of transcriptome and proteome analyses as a tool for the systematic comprehension of cellular mechanisms in CHO cells. © 2005 Wiley Periodicals, Inc.
Pulsed Gradient Spin Echo (PGSE) Diffusion Measurements as a Tool for the Elucidation of a New Type of Hydrogen‐Bonded Bicapsular Aggregate
Authors: Alajarín Mateo , Pastor Aurelia , Orenes Raúl‐Angel , Martínez‐Viviente Eloísa , Pregosin Paul S. 
Published: September 2005

AbstractCompounds formed by linking two tris(ureidobenzyl)amine modules with a hexamethylene tether are described. These compounds self‐assemble to form bicapsular aggregates featuring two rings of six hydrogen‐bonded ureas. 1H and 1H/1H ROESY NMR spectroscopy, together with pulsed gradient spin echo (PGSE) NMR diffusion measurements, have been used to characterize the dimers in solution. The results have been compared with energy‐minimized structures. The new compounds are kinetically stable on the NMR timescale, and their thermodynamic stabilities are comparable to other capsular aggregates derived from tris(ureidobenzyl)amines.
Tunable Charge Delocalization in Dinickel Quinonoid Complexes
Authors: Siri Olivier , Taquet Jean‐philippe , Collin Jean‐Paul , Rohmer Marie‐Madeleine , Bénard Marc , Braunstein Pierre 
Published: September 2005

AbstractWhen a 2,5‐diamino‐1,4‐benzoquinonediimine C6H2(NR)2(NHR)2(2) is used as a bridging ligand, new dinickel(II) complexes [(acac)Ni{μ‐C6H2(${^{\underline{.....}}}$NPh)4}Ni(acac)] (3 a: R=Ph) and [(acac)Ni{μ‐C6H2(${^{\underline{.....}}}$NCH2tBu)4}Ni(acac)] (3 b: R=CH2tBu) are obtained; upon one‐electron oxidation of these complexes delocalized mixed‐valence compounds are formed. An X‐ray diffraction study on3 breveals equalization of the bond lengths within each of the ligand 6π systems and a lack of conjugation between them. The oxidized state in3 b+involves both the bridging quinonoid ligand and the metal centers, with a major contribution coming from the bridging ligand. Electrochemical and spectroscopic methods were used to study the influence of the N‐substituents of the tetranitrogen donor ligands2. In this combined experimental and theoretical (DFT) study, it is also shown that the electronic structure within the dinickel system can be altered by addition of a coordinating ligand such as pyridine. The latter favors the high‐spin configuration with semi‐occupied metal‐centered orbitals, leading to a metal–metal interaction in the mixed‐valence NiII–NiIII3 b+system.
Structural, Electronic, and Bonding Properties of Zeolite Sn‐Beta: A Periodic Density Functional Theory Study
Authors: Shetty Sharan , Pal Sourav , Kanhere Dilip G. , Goursot Annick 
Published: September 2005

AbstractThe structural, electronic, and the bonding properties of the zeolite Sn‐beta (Sn‐BEA) have been investigated by using the periodic density functional theory. Each of the nine different T‐sites in BEA were substituted by Sn atoms and all the nine geometries were completely optimized by using the plane‐wave basis set in conjunction with the ultra‐soft pseudopotential. On the basis of the structural and the electronic properties, it has been demonstrated that the substitution of Sn atoms in the BEA framework is an endothermic process and hence the incorporation of Sn in the BEA is limited. The lowest unoccupied molecular orbitals (LUMO) energies have been used to characterize the Lewis acidity of each T‐site. On the basis of the relative cohesive energy and the LUMO energy, the T2 site is shown to be the most favorable site for the substitution Sn atoms in the BEA framework.
Self‐Assembly of Dialkyltin Moieties and Mercaptobenzoic Acid into Macrocyclic Complexes with Hydrophobic “Pseudo‐Cage” or Double‐Cavity Structures: Supramolecular Infrastructures Involving Intermolecular CH⋅⋅⋅S Weak Hydrogen Bonds and π–π Interactions
Authors: Ma Chunlin , Zhang Qingfu , Zhang Rufen , Wang Daqi 
Published: September 2005

AbstractFour novel organotin complexes of two types—[R2Sn(o‐SC6H4CO2)]6(R=Me,1⋅H2O;nBu,2) and {[R2Sn(m‐CO2C6H4S)R2Sn(m‐SC6H4CO2)SnR2]O}2(R=Me,3;nBu,4)—have been prepared by treatment ofo‐ orm‐mercaptobenzoic acid and the corresponding R2SnCl2(R=Me,nBu) with sodium ethoxide in ethanol (95 %). All the complexes were characterized by elemental analysis, FT‐IR and NMR (1H,13C,119Sn) spectroscopy, TGA, and X‐ray crystallography diffraction analysis. The molecular structure analyses reveal that both1and2are hexanuclear macrocycles with hydrophobic “pseudo‐cage” structures, while3and4are hexanuclear macrocycles with double‐cavity structures. Furthermore, the supramolecular structure analyses show that looser and more intriguing supramolecular infrastructures were also found in complexes1–4, which exist either as one‐dimensional chains of rings or as two‐dimensional networks assembled from the organometallic subunits through intermolecular CH⋅⋅⋅S weak hydrogen bonds (WHBs) and π–π interactions.
Photoinduced Oxygen Transfer and Double‐Linkage Isomerism in a cis‐(NO)(NO2) Transition‐Metal Complex by Photocrystallography, FT‐IR Spectroscopy and DFT Calculations
Authors: Kovalevsky Andrey Yu , King Graham , Bagley Kimberly A. , Coppens Philip 
Published: September 2005

AbstractPhotocrystallographic experiments show that laser exposure of crystals of [Ru(bpy)2(NO)(NO2)](PF6)2 at 90 K produces a double isonitrosyl–nitrito linkage isomer and provide the detailed geometry of the metastable species generated. The analysis indicates that the isomerization is accomplished through an intramolecular redox reaction involving oxygen transfer from the nitro to the nitrosyl group. At 200 K only a single (nitrito) linkage isomer is formed with a U‐shaped conformation of the nitrito group rather than the Z conformation observed at 90 K. A mechanism for the isomerization is proposed based on the crystallographic results and FTIR data collected at low temperatures during the isomerization process. The study presents the first structural evidence for double linkage isomerization in transition‐metal complexes.
Synthesis of Nitrogen‐ and Oxygen‐Containing Macrocycles—Derivatives of Lithocholic Acid
Authors: Averin Alexei D. , Ranyuk Elena R. , Lukashev Nikolai V. , Beletskaya Irina P. 
Published: September 2005

AbstractPalladium‐catalyzed amination of 3,24‐bis(3‐bromophenoxy)cholane (4) with various polyamines and polyoxadiamines 5 taken in 1:1 ratio was used for the synthesis of the macrocycles 6, which contain steroidal and polyamine moieties and were obtained in 38–65 % yields. The same reaction with excess polyamine (2.2–3 equiv) provided bis(polyamino) derivatives of 3,24‐diphenoxycholane 7 in excellent yields, whereas the diarylation of polyamines with two equivalents of 3,24‐bis(3‐bromophenoxy)cholane afforded their bis(steroidal) derivatives 8. Compounds 7 and 8 were employed in the syntheses of cyclodimers 9, which possess two steroidal and two polyamine fragments; the efficiency of two methods was compared.
Recognition‐Induced Polymersomes: Structure and Mechanism of Formation
Authors: Uzun Oktay , Xu Hao , Jeoung Eunhee , Thibault Raymond J. , Rotello Vincent M. 
Published: September 2005

AbstractRandom polystyrene copolymers grafted with complementary recognition elements were combined in chloroform producing vesicular aggregates, that is, recognition‐induced polymersomes (RIPs). Reflection interference contrast microscopy (RICM) in solution, coupled with optical microscopy (OM) and atomic force microscopy (AFM) on solid substrates, were used to determine the wall thickness of the RIPs. Rather than a conventional mono‐ or bilayer structure (∼10 or ∼20 nm, respectively) the RIP membrane was 43±7 nm thick. Structural arrangement of the polymer chains on the RIP wall were characterized by using angle‐resolved X‐ray photoelectron spectroscopy (AR‐XPS). The interior portion of the vesicle membrane was found to be more polar, containing more recognition units, than the exterior part. This gradient suggests that a rapid self‐sorting of polymers takes place during the formation of RIPs, providing the likely mechanism for vesicle self‐assembly.
Synthesis, Liquid‐Crystalline Properties, and Supramolecular Nanostructures of Dendronized Poly(isocyanide)s and Their Precursors
Authors: Tian Yanqing , Kamata Kaori , Yoshida Hirohisa , Iyoda Tomokazu 
Published: September 2005

AbstractA series of novel dendronized π‐conjugated poly(isocyanide)s were synthesized successfully by using a PdPt μ‐ethynediyl dinuclear complex ([ClPt{P(C2H5)3}2CCPt{P(C2H5)3}2Cl]) as the initiator. The polymerizations of the dendronized monomers follow first‐order kinetics, indicating that living polymerization takes place. The obtained polymers exhibit narrow polydispersities in the range of 1.03–1.20. Thermal properties of the poly(isocyanide)s as well as their isocyanide monomers and precursors with formamido (HCONH‐) moieties as apexes were investigated by using differential scanning calorimetry (DSC), polarized optical microscopy (POM) and wide‐angle X‐ray diffraction (WAXD). Both the peripheries and the apex groups of the dendrons affect the formation of supramolecular column and/or cubic phases of the precursors and monomers. The formamido precursor forms a liquid‐crystalline phase due to intermolecular hydrogen bonding. The isocyanide monomer lacks this hydrogen‐bonding ability and does not display an organized mesophase. All of the rigid poly(isocyanide)s with the monodendrons exhibit columnar liquid‐crystalline phases. Interestingly, cylindrical structures of a poly(isocyanide) were directly visualized by using transmission electron microscopy (TEM).
Investigations of molecular recognition aspects related to the enantiomer separation of 2‐methoxy‐2‐(1‐naphthyl)propionic acid using quinine carbamate as chiral selector: An NMR and FT‐IR spectroscopic as well as X‐ray crystallographic study†
Authors: Akasaka Kazuaki , Gyimesi‐Forrás Krisztina , Lämmerhofer Michael , Fujita Takuma , Watanabe Masataka , Harada Nobuyuki , Lindner Wolfgang 
Published: September 2005

AbstractThe chiral recognition mechanism of a cinchona alkaloid‐based chiral stationary phase (CSP) showing high enantiomer discrimination potential for 2‐methoxy‐2‐(1‐naphthyl)propionic acid (MαNP acid) was investigated. Conformational and structural analyses of the 1:1 complexes of 9‐O‐(tert‐butylcarbamoyl) quinine selector (SO) and MαNP acid (selectand, SA) were carried out employing NMR spectroscopy in solution, Fourier‐transform infrared (FT‐IR) spectroscopy, and solid‐state X‐ray diffraction analysis. Intramolecular NOEs of a soluble analogue of the CSP afforded the conformational states of the free and complexed form of the selector. The 1H‐NMR spectra revealed that the free form of the SO constitutes anti‐open as well as anti‐closed and/or syn‐closed conformers. Upon complexation with the (S)‐MαNP acid enantiomer to form the more stable diastereomeric associate, a conformational transition of the selector takes place, resulting in the synthesis of the anti‐open conformer nearly exclusively. FT‐IR spectra reveal that, besides the primary ion‐pairing interaction, stereoselective hydrogen bonding stabilizes the more stable complex via the amide hydrogen of the SO. X‐ray diffraction analysis of 9‐O‐(tert‐butylcarbamoyl)quinine and (S)‐MαNP acid complex further revealed the occurrence of a bidentate H‐bond‐mediated ionic interaction between SO and SA as well as the lack of π–π interaction in the 1:1 complex, and corroborated the conclusions derived from spectroscopic and chromatographic studies. © 2005 Wiley‐Liss, Inc. Chirality 17:544–555, 2005.
β‐cyclodextrin‐immobilized (4S)‐phenoxy‐(S)‐proline as a catalyst for direct asymmetric aldol reactions
Authors: Shen Zongxuan , Ma Jimei , Liu Yanhua , Jiao Chongjun , Li Ming , Zhang Yawen 
Published: September 2005

Abstractβ‐Cyclodextrin‐immobilized (4S)‐phenoxy‐(S)‐proline was prepared conveniently by simply heating the amino acid and β‐cyclodextrin in ethanol–water (1/1, v/v) and removal of the solvent. This proved to be an efficient catalyst for direct asymmetric aldol reactions, and the catalyst could be recycled four times without loss of enantioselectivity. © 2005 Wiley‐Liss, Inc. Chirality 17:556–558, 2005.
Inversely Polarized Phosphaalkenes as Phosphinidene‐ and Carbene‐Transfer Reagents
Authors: Weber Lothar , Lassahn Ulrich , Stammler Hans‐Georg , Neumann Beate 
Published: September 2005

AbstractThe reaction of the inversely polarized phosphaalkenes RP=C(NMe2)2[R =tBu (1a), Cy (1b), 1‐Ad (1c), Ph (1d), Mes (1e)] with an excess of diphenyl ketene inn‐pentane affords the zwitterionic adduct (Me2N)2C–C(O)=CPh2(2) and the 3,5‐dibenzhydrylidene‐1,4,2‐dioxaphospholanes4a–e. The reaction of1awith Ph2C=C=O in concentrated acetonitrile solution gives4aand 5‐benzhydrylidene‐2‐tert‐butyl‐4,4‐diphenyl‐1,2‐oxaphospholan‐3‐one (6a) as a by‐product. In contrast, treatment of Me3SiP=C(NMe2)2(1i) with the ketene leads to the formation of 2‐phospha‐1,3‐butadiene (5). The thermolabile phosphaalkene8decomposes into an imidazolylidene and (tBuP), the latter species spontaneously oligomerizes to (tBuP)n(n= 3, 4). Obviously, compounds1a–eserve as a convenient source of phosphinidenes and the carbene C(NMe2)2. A Wanzlick‐type equilibrium between these species, however, must be excluded according to exchange and cross‐coupling experiments. The molecular structures of2,4eand6awere determined by X‐ray structure analyses. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Synthesis and Thermal Denaturation Studies of Conformationally Restricted 3′‐C‐Ethynyl‐3′‐O,4′‐C‐methyleneribonucleotides
Authors: Hrdlicka Patrick J. , Kumar T. Santhosh , Wengel Jesper 
Published: September 2005

AbstractIncorporation of conformationally restricted 3′‐C‐ethynyl‐3′‐O,4′‐C‐methyleneribonucleotide X monomers into oligodeoxyribonucleotides results in large decreases in affinity towards complementary DNA, whereas significantly more stable duplexes are formed with RNA complements. RNA selectivity becomes more pronounced upon multiple incorporations of X monomers. Increased thermal stability is observed upon positioning of two X monomers in a +1 zipper interstrand motif. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Wood storage in a wide mountain river: case study of the Czarny Dunajec, Polish Carpathians
Authors: Wyżga Bartłomiej , Zawiejska Joanna 
Published: September 2005

AbstractStorage of large woody debris in the wide, mountain, Czarny Dunajec River, southern Poland, was investigated following two floods of June and July 2001 with a seven‐year frequency. Within a reach, to which wood was delivered only by bank erosion and transport from upstream, wood quantities were estimated for eighty‐nine, 100 m long, channel segments grouped into nine sections of similar morphology. Results from regression analysis indicated the quantity of stored wood to be directly related to the length of eroded, wooded banks and river width, and inversely related to unit stream power at the flood peak. The largest quantities of wood (up to 33 t ha−1) were stored in wide, multi‐thread river sections. Here, the relatively low transporting ability of the river facilitated deposition of transported wood while a considerable length of eroded channel and island banks resulted in a large number of trees delivered from the local riparian forest. In these sections, a few morphological and ecological situations led to the accumulation of especially large quantities of wood within a small river area. Very low amounts of wood were stored in narrow, single‐thread sections of regulated or bedrock channel. High stream power facilitated transport of wood through these sections while the high strength of the banks and low channel sinuosity prevented bank retreat and delivery of trees to the channel.Considerable differences in the character of deposited wood existed between wide, multi‐thread channel sections located at different distances below a narrow, 7 km long, channellized reach of the river. Wood deposited close to the downstream end of the channellized reach was highly disintegrated and structured into jams, whereas further downstream well preserved shrubs and trees prevailed. This apparently reflects differences in the distance of wood transport and shows that in a mountain river wider than the height of trees growing on its banks, wood can be transported long distances along relatively narrow, single‐thread reaches but is preferentially deposited in wide, multi‐thread reaches. Copyright © 2005 John Wiley & Sons, Ltd.
Till deposition by glacier submarginal, incremental thickening
Authors: Evans David J. A. , Hiemstra John F. 
Published: September 2005

AbstractMacro‐ and micro‐scale sedimentological analyses of recently deposited tills and complex push/squeeze moraines on the forelands of Icelandic glaciers and in a stacked till sequence at the former Younger Dryas margin of the Loch Lomond glacier lobe in Scotland are used to assess the depositional processes involved in glacier submarginal emplacement of sediment. Where subglacial meltwater is unable to flush out subglacial sediment or construct thick debris‐rich basal ice by cumulative freeze‐on processes, glacier submarginal processes are dictated by seasonal cycles of refreezing and melt‐out of tills advected from up‐ice by a combination of lodgement, deformation and ice keel and clast ploughing. Although individual till layers may display typical A and B horizon deformation characteristics, the spatially and temporally variable mosaic of subglacial processes will overprint sedimentary and structural signatures on till sequences to the extent that they would be almost impossible to classify genetically in the ancient sediment record. At the macro‐scale, Icelandic tills display moderately strong clast fabrics that conform to the ice flow directions documented by surface flutings; very strong fabrics typify unequivocally lodged clasts. Despite previous interpretations of these tills as subglacial deforming layers, micro‐morphological analysis reveals that shearing played only a partial role in the emplacement of till matrixes, and water escape and sediment flowage features are widespread. A model of submarginal incremental thickening is presented as an explanation of these data, involving till slab emplacement over several seasonal cycles. Each cycle involves: (1) late summer subglacial lodgement, bedrock and sediment plucking, subglacial deformation and ice keel ploughing; (2) early winter freeze‐on of subglacial sediment to the thin outer snout; (3) late winter readvance and failure along a decollement plane within the till, resulting in the carriage of till onto the proximal side of the previous year's push moraine; (4) early summer melt‐out of the till slab, initiating porewater migration, water escape and sediment flow and extrusion. Repeated reworking of the thin end of submarginal till wedges produces overprinted strain signatures and clast pavements. Copyright © 2005 John Wiley & Sons, Ltd.
Effect of dyke construction on water dynamics in the flooding savannahs of Venezuela
Authors: Smith J. K. , Chacón‐Moreno E. J. , Jongman R. H. G. , Wenting Ph. , Loedeman J. H. 
Published: September 2005

AbstractIn the flooded savannahs water is the main factor determining the ecosystem and its change. During flooding, the level of water and the duration of flooding are highly dependent on the relative height position of the ecosystem unit. To understand the spatial processes in the ecosystem one must know the water dynamics in the area. In order to quantify the water content during the year, a digital elevation model (DEM) is needed.Several areas in the Llanos de Orinoco have been dyked (modulos). A digital elevation model has been developed on a level of the dyked area of the modulo of Hato el Frio. Flooding has been studied at the regional level and a DEM has been developed for the modulo area. For the construction of the DEM various sources were explored for height information. Field measurements with GPS were necessary.After the high flooding period downstream of the dykes the area is totally dry. In the transition period between the dry and the wet season the distribution of water shows a clear influence of the dyke. In the natural situation the natural height differences create a complex system of sinks. The dyke construction has created a large artificial sink. Modulos form sinks by their banks preventing the outflow of the water. With the help of a DEM, inundation can be modelled with relatively little field research. Copyright © 2005 John Wiley & Sons, Ltd.