bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mixed Titanium–Hafnium Chloridometallate Complexes
Authors: Robé Emmanuel , Maria Sébastien , Richard Philippe , Poli Rinaldo 
Published: April 2007

AbstractThe addition of either NEt3BzCl or [Ph3PNPPh3]Cl (1 equiv. chloride per metal) to a 1:1 mixture of HfCl4 and TiCl3 in SOCl2 results in Ti oxidation and leads to the corresponding salts of the [TiHfCl10]2– ion. A solution IR investigation in the ν(M–Cl) region indicates that this ion is in equilibrium with the homodimetallic [Ti2Cl10]2– and [Hf2Cl10]2– ions. An X‐ray study of the NEt3Bz+ salt reveals an edge‐sharing bioctahedral dianion sitting on a crystallographic inversion centre. The crystal is a solid solution of different species with compositional disorder at the metal site, each metal position having the occupancy Ti0.685Hf0.315. The M–M and M–Cl distances have intermediate values between those of the homodimetallic analogues. The results of DFT calculations rationalize the structural, energetic and M–Cl bonding differences. An electrochemical investigation, in comparison with that of [Ti2Cl10]2– and the parallel IR studies, provides further information on the solution equilibria. Adventitious hydrolysis during the crystallization of the [Ph3PNPPh3]+ salt affords crystals of [Ph3PNPPh3]2[Cl3Ti(μ‐O)HfCl5], whose dianion contains a tetrahedral TiIV centre and an octahedral HfIV centre bridged by an oxygen atom. A bond‐length analysis allows the description of this dianion as containing the hitherto unknown [Ti(O)Cl3]– complex, which acts as an oxygen‐based donor ligand to [HfCl5]–. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Synthesis, Coordination and Catalytic Utility of Novel Phosphanyl–ferrocenecarboxylic Ligands Combining Planar and Central Chirality
Authors: Lamač Martin , Císařová Ivana , Štěpnička Petr 
Published: April 2007

AbstractThe chiral ferrocene derivative (R,Rp)‐2‐[1‐(diphenylphosphanyl)ethyl]ferrocenecarboxylic acid (1) is prepared together with selected derivatives resulting from modification at the phosphane moiety [P‐oxide (5) and P‐sulfide (4)] and the carboxyl group {amides bearing benzyl (6) and (R)‐ or (S)‐1‐phenylethyl substituents [(R)‐7 and (S)‐7] at the amide nitrogen atom}. Acid 1 and amide 6 are studied as ligands in rhodium and palladium complexes. Bridge cleavage of the dimer [{Rh(μ‐Cl)Cl(η5‐C5Me5)}2] with 1 gives [RhCl2(η5‐C5Me5)(1‐κP)] (9) containing P‐monodentate 1, which undergoes smooth conversion to the (phosphanylalkyl)ferrocenecarboxylato complex [RhCl(η5‐C5Me5){Fe(η5‐C5H5)(η5‐C5H3‐1‐CH(Me)PPh2‐2‐COO‐κ2O,P}] (10) upon treatment with silica gel or alumina. Yet another O,P‐chelate complex,[Rh{Fe(η5‐C5H5)(η5‐C5H3‐1‐CH(Me)PPh2‐2‐COO‐κ2O,P}(CO)(PCy3)] (11; Cy = cyclohexyl) is obtained directly by an acid‐base reaction between the acetylacetonato complex [Rh(acac)(CO)(PCy3)] and 1. Amide 6 reacts with [{Pd(μ‐Cl)(η3‐C3H5)}2] to give the expected phosphane complex [PdCl(η3‐C3H5)(6‐κP)] (12), while the replacement of the cyclooctadiene (cod) ligand in [PdCl(Me)(cod)] affords the chelate complex [PdCl(Me)(6‐κ2O,P)] (13). All compounds are characterised by spectroscopic methods and the solid‐state structures of 5, 9, 11, 13, (R,Sp)‐2‐[1‐(diphenylphosphoryl)ethyl]‐1‐[N‐(R)‐(1‐phenylethyl)carbamoyl]ferrocene [(R)‐8; phosphane oxide from (R)‐7], and the synthetic precursors (R,Sp)‐1‐bromo‐2‐[1‐(diphenylphosphanyl)ethyl]ferrocene (2) and (R,Sp)‐1‐bromo‐2‐[1‐(diphenylthiophosphoryl)ethyl]ferrocene (3) determined by single‐crystal X‐ray diffraction. The catalytic properties of 1 and the amides are probed in enanatioselective rhodium‐catalysed hydrogenation and palladium‐catalysed asymmetric allylic alkylation. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Acute cognitive effects of standardised Ginkgo biloba extract complexed with phosphatidylserine
Authors: Kennedy D. O. , Haskell C. F. , Mauri P. L. , Scholey A. B. 
Published: April 2007

AbstractRecent data suggest that the complexation of standardised Ginkgo biloba extract (GBE) with soy‐derived phospholipids enhances the bio‐availablity of GBE's active components. The current study therefore aimed to assess the comparative cognitive and mood effects of a low dose of GBE and products complexing the same extract with either phosphatidylserine or phosphatidylcholine.The study utilised a placebo‐controlled, multi‐dose, double‐blind, balanced‐crossover design. Twenty‐eight healthy young participants received 120 mg GBE, 120 mg GBE complexed with phosphatidylserine (Virtiva™), 120 mg GBE complexed with phosphatidylcholine and a matching placebo, on separate days 7 days apart. Cognitive performance was assessed using the Cognitive Drug Research (CDR) computerised test battery and Serial Subtraction tasks immediately prior to dosing and at 1, 2.5, 4 and 6 h thereafter. The primary outcome measures were the four aspects of cognitive performance, which have previously been derived by factor analysis of CDR subtests. Levels of terpenoids (bilobalide, ginkgolide A and ginkgolide B) were concomitantly assessed in plasma samples taken pre‐dose and at 3 and 6.5 h post‐dose.In keeping with previous research utilising the same methodology, 120 mg of GBE was not associated with markedly improved performance on the primary outcomes. However, administration of GBE complexed with phosphatidylserine resulted both in improved secondary memory performance and significantly increased speed of memory task performance across all of the post‐dose testing sessions. Enhancement following GBE complexed with phosphatidylcholine was restricted to a modest improvement in secondary memory performance which was restricted to one post‐dose time point. All three treatments were associated with improved calmness. There were no significant differences in post‐dose levels of terpenoids between the Ginkgo containing treatments, although this latter finding may be attributable to methodological factors.Complexation with phosphatidylserine appears to potentiate the cognitive effects associated with a low dose of GBE. Further research is required to identify whether this effect is due to the complexation of the extracts, their mere combination, or the separate psychopharmacological actions of the two extracts. Copyright © 2007 John Wiley & Sons, Ltd.
Aid and competition in procurement auctions: a case of highway projects
Authors: Iimi Atsushi 
Published: April 2007

AbstractAuctions have been recognised as an important tool for improving economic efficiency. Aid‐related procurement systems are no exception to this. Strengthening competition at procurement auctions lowers contract prices and mitigates the heavy indebtedness of developing countries. Auctions are also instrumental in developing local business and fostering good governance. Using data on procurement auctions for Asian Development Bank‐assisted highway projects in China, the equilibrium bid function is estimated. The data indicate that two factors may exert different influences on the equilibrium bid. A common expectation that economies of scale in road construction could lower the average cost of constructing relatively long roads encourages firms to bid aggressively, independently of the degree of auction competition. On the other hand, a pro‐competitive effect would be observed only as the number of bidders exceeds eight. Copyright © 2007 John Wiley & Sons, Ltd.
The poverty transition: when, how and what next?
Authors: Mahadevan Renuka 
Published: April 2007

AbstractThis paper draws attention to an aspect of poverty reduction in rapidly developing economies that have enjoyed a sustained period of economic growth accompanied by a decline in absolute poverty. The paper sets out to show the following: First, growth that leaves income distribution unchanged necessarily involves the poor in its early stages. Second, as income grows and absolute poverty declines, and in the absence of distributional changes, the gap between absolute and relative poverty diminishes until it disappears at an identifiable transition point, after which the relationship between the two poverty types is reversed. Although this is examined in the specific context of the Malaysian economy, the analysis has much wider application and implications for poverty alleviation in particular, and policy development in general, as the latter will involve a more difficult balancing of growth and equity than in the past. Copyright © 2007 John Wiley & Sons, Ltd.
Synthesis of 14C‐labeled piperidines and application to synthesis of [14C]SCH 351125, a CCR5 receptor antagonist
Authors: Ren Sumei , McNamara Paul , Royster Pernilla , Lee Jae , Saluja Surinderjit S. , Koharski David , Hendershot Sharon , Truong Van 
Published: April 2007

Abstract1‐Benzyl‐4‐hydroxy[2‐14C]piperidine, a useful intermediate in labeled compound synthesis, was prepared from [14C]formaldehyde in high yield. The distribution pattern of 14C in the product is consistent with a mechanism involving reversible iminium ion formation and rapid equilibration of the iminium ion through a cationic aza‐Cope rearrangement. These steps precede the rate‐determining intramolecular cyclization step. SCH 351125 is a potent, selective CCR5 receptor antagonist with potential as a treatment for HIV infection. [14C]SCH 351125, required for metabolism studies, was prepared from 1‐benzyl‐4‐hydroxy[2‐14C]piperidine in six steps. [14C]SCH 351125 is a mixture of four atropisomers. Preparation of [14C]SCH 351125 besylate salt of the desired atropisomer pair is also described. Copyright © 2007 John Wiley & Sons, Ltd.
Snow cover variability in Poland in relation to the macro‐ and mesoscale atmospheric circulation in the twentieth century
Authors: Falarz Małgorzata 
Published: April 2007

AbstractThe main aim of the study is to investigate the atmospheric circulation impact on snow cover duration (SCD) and maximum seasonal depth of snow cover (MDS) in Poland in the twentieth century. The most important is to answer four questions: (1) which of the two, macro‐ or mesoscale atmospheric circulation, dominates in influencing the snow cover variability and changes in Poland area? (2) which of the two, meridional (S–N/N–S) or zonal (W–E/E–W) advection, dominates in influencing the snow cover variability and changes? (3) are the atmospheric circulation–snow cover relationships stable with time or did they change in circulation epochs? (4) does any strong relation exist between the snow cover in Poland and the atmospheric circulation enabling the possibility to forecast the nival conditions for the next winter season?The principal results of the study are as follows: (1) the macroscale circulation connected to atmospheric patterns over the Atlantic Ocean impacts stronger on the SCD variability in Poland than the circulation patterns located directly over the Poland area; (2) during the period 1966/67–1995/96 the zonal circulation dominated over the meridional one in influencing the SCD variability and change (the exceptions were areas with the most intensive foehn effect); (3) the decreasing trend of the dependence strength of the SCD on the meridional circulation with respect to the increasing tendency for zonal circulation‐SCD impact was observed in the twentieth century; (4) the meridional circulation dominated over the zonal one in influencing the SCD till the 1930s of the twentieth century only (5) the snow cover in Poland is positively correlated with the North Atlantic Oscillation (NAO) in October prior to the winter season.The instability of the snow cover dependence on the atmospheric circulation in the twentieth century corresponds roughly to the circulation epochs and periods of intensity changes of the zonal/meridional advection over Europe. Copyright © 2007 Royal Meteorological Society
A Degradable Hyperbranched Poly(ester amine) Based on Poloxamer Diacrylate and Polyethylenimine as a Gene Carrier
Authors: Kim Tae Hee , Cook Seung Eun , Arote Rohidas B. , Cho Myung‐Haing , Nah Jae Woon , Choi Yun Jaie , Cho Chong Su 
Published: April 2007

AbstractPolyethylenimine (PEI) is a well‐known cationic polymer which has high transfection efficiency due to its buffering effect. However, nondegradability, cytotoxicity, aggregation, and short‐circulation time in vivo still need to be overcome for a successful gene delivery. Degradable, hyperbranched poly(ester amine)s (PEAs) based on poloxamer diacrylate and low molecular weight branched PEI, were successfully synthesized and evaluated as a nonviral gene carrier. The PEAs were obtained in significant yields through Michael type addition reaction of diacrylate monomers and low molecular weight branched PEI. Analysis of degradation products by the reduction in molecular weight demonstrated that PEAs degrade in a controlled fashion. The PEA showed good DNA binding ability and the sizes of complexes under physiological condition were below 150 nm, implicating its potential for intracellular delivery. It showed lower cytotoxicity in three different cell lines (A549, 293T, and HepG2) compared with PEI 25K. PEAs showed much higher transfection efficiencies in three cell lines compared with PEI 25K and PEI 1.8K, and revealed little serum dependency in A549 cell line when the content of poloxamer in the PEA was increased up to 30%.magnified image
Synthesis and Erosion Properties of PEG‐Containing Polyanhydrides
Authors: Hou Sijian , McCauley Laurie K. , Ma Peter X. 
Published: April 2007

AbstractTo tailor the erosion rate of polyanhydrides while retaining their surface erosion characteristics, new three‐component polyanhydrides of sebacic acid, 1,3‐bis(p‐carboxyphenoxy)propane and poly(ethylene glycol) were synthesized. The hydrophilicity of the polymer increased and its mechanical strength decreased with increasing PEG content. Correspondingly, the erosion rate increases with increasing PEG content, whereas it decreases with increasing specimen thickness. This indicates that the incorporation of poly(ethylene glycol) into traditional two‐component polyanhydrides retains their surface erosion properties while making the erosion rate tunable. The new polyanhydrides hold potential for drug delivery applications.magnified image
Evaluation of Modified CMC and CMC‐PVA as Miscible Polymer Blend Membranes for Hepatocytes
Authors: Koç Aysel , Durkut Serap , Elçin A. Eser , Tan Erdal , Elçin Y. Murat 
Published: April 2007

AbstractCMC and CMC‐PVA were blended either with type I collagen, BSA or CS to obtain biocompatible membranes for evaluation as potential hepatocyte culture substrates. Pure and modified forms of CMC showed distinct surface, mechanical, and cell attachment properties. While the hydrophilicity decreased, the mechanical stability and the porosity of CMC membranes increased after blending. Serum proteins were adsorbed by all types of membranes. Among eight membranes tested, collagen‐modified CMC was found to be a suitable membrane material for hepatocyte culture, in terms of mechanical and cell interaction properties.magnified image
Human Hepatocyte Morphology and Functions in a Multibore Fiber Bioreactor
Authors: De Bartolo Loredana , Morelli Sabrina , Rende Maria , Campana Carla , Salerno Simona , Quintiero Nino , Drioli Enrico 
Published: April 2007

AbstractThe viability and liver specific functions of human hepatocytes in a multibore fiber bioreactor are reported. Human hepatocytes were cultured in the intraluminal compartment of the bioreactor. Human hepatocytes on the membranes maintained their round shape and showed focal adhesions as sites of interaction with the membrane surface. Cells in the bioreactor expressed liver specific functions, including synthetic and detoxification activity up to 14 d of culture. The results demonstrate that human hepatocytes cultured in the multibore fiber bioreactor are able to sustain the same in vivo liver functions in vitro.magnified image
The Interaction of Cationic Polymers and Their Bisphosphonate Derivatives with Hydroxyapatite
Authors: Zhang Sufeng , Wright Jennifer E. I. , Özber Natali , Uludağ Hasan 
Published: April 2007

AbstractConjugating proteins with bisphosphonates (BPs), a class of molecules with exceptional affinity to hydroxyapatite (HA), is a feasible means to impart bone affinity to protein‐based therapeutic agents. To increase the targeting effectiveness while minimizing protein modification, a polymeric linker containing multiple copies of BPs could be constructed for protein conjugation and targeting to bone. Towards this goal, poly(L‐lysine) (PLL) and poly(ethylenimine) (PEI) were utilized as the polymeric backbones to incorporate a BP, namely 2‐(3‐mercaptopropylsulfanyl)‐ethyl‐1,1‐bisphosphonic acid (thiolBP), by using N‐hydroxysuccinimidyl polyethylene glycol maleimide and succinimidyl‐4‐(N‐maleimidomethyl)‐cyclohexane‐1‐carboxylate, respectively. In vitro and in vivo mineral affinity of the polymer‐BP conjugates were determined in comparison with the unmodified polymers. The in vitro results indicated strong binding of the cationic polymers to HA in their unmodified form. BP conjugation did not enhance the inherent mineral affinity of the polymers; in contrast, certain modifications negatively affected the polymers' binding to the HA. In vivo results from a subcutaneous implant model in rats also showed no significant difference in mineral affinity of the BP modified and unmodified PEI. We conclude that thiolBP conjugation to the cationic polymers PLL and PEI was not beneficial for increasing the mineral affinity of the polymeric molecules. The strong interaction between the cationic polymers and HA may make the polymers suitable for imparting mineral affinity to bone‐acting therapeutics.magnified image
Interface Interactions of Osteoblasts with Structured Titanium and the Correlation between Physicochemical Characteristics and Cell Biological Parameters
Authors: Nebe J. G. Barbara , Luethen Frank , Lange Regina , Beck Ulrich 
Published: April 2007

AbstractCellular behavior at the interface of an implant is influenced by the material's topography. However, little is known about the correlation between the biological parameters and the physicochemical characteristics of the biomaterial. We therefore modified pure titanium surfaces by polishing, machining, blasting with glass spheres, blasting with corundum particles, and vacuum plasma spraying to give progressively higher surface roughness. The material surface was characterized by SEM, surface profiling, and electrochemical methods. We revealed a correlation for integrin expression and formation, adhesion, spreading, proliferation, and bone sialo protein expression with the physicochemical parameters of the titanium surfaces.magnified image
Chondroitin‐4‐Sulfate: A Bioactive Macromolecule to Foster Vascular Healing around Stent‐Grafts after Endovascular Aneurysm Repair
Authors: Charbonneau Cindy , Gautrot Julien E. , Hébert Marie‐Josée , Zhu X. X. , Lerouge Sophie 
Published: April 2007

AbstractDeficient healing after endovascular aneurysm repair with a stent‐graft is thought to be related to pro‐apoptotic environment in abdominal aortic aneurysms and inertness of graft materials. We developed a bioactive coating containing chondroitin‐4‐sulfate and assessed its potential to improve cell adhesion, viability and resistance to apoptosis on PET surfaces. Coatings of collagen type I and CS were prepared and characterized by DMMB, FT‐IR, DSC, SEM and contact angle goniometry. Preliminary cell culture experiments with vascular smooth muscle cells showed increased adhesion and viability in serum‐free medium on CS‐coated surfaces compared to control PET films.magnified image
Pole Approximation and Spectral Concentration
Authors: Demuth M. 
Published: April 2007

AbstractAn asymptotic error estimation of the pole approximation is given by means of spectral concentration in the onedimensional Friedrichs' model.Übersicht. Mit Hilfe der Spektralkonzentration wird für ein eindimensionales Friedrichs‐Modell die Güte der Polapproximation asymptotisch abgeschätzt.
Des catégories respectivement équivalentes à celles des espaces affines et des modules
Authors: Batbedat André 
Published: April 2007

AbstractNous rnontrons que la catégorie des espaces affines (avec anneau variable) est équivalente à une catégorie d'anneaux et plus naturellement à une catégorie de préanneaux. On examine quelques cas particuliers, précise certains applications et présente des généralisations. Ces résultats s'adaptent facilement aux modules.
Diagnose von Schlafstörungen und Tagesschläfrigkeit: Wenn der Schlaf nicht mehr erholsam ist – Ursachen und Folgen
Authors: Popp Roland , Geisler Peter 
Published: April 2007

AbstractSchlafstörungen haben sowohl eine Störung der physiologischen Erholungsfunktion des Schlafes in der Nacht als auch negative Auswirkungen auf die Befindlichkeit und Leistungsfähigkeit am Tag zur Folge. Ein wesentliches Leitsymptom in der Diagnostik ist die Tagesschläfrigkeit.Mit der kardiorespiratorischen Polysomnographie kann der Schlafablauf objektiviert werden. Zugleich können die häufigsten Ursachen für einen nicht erholsamen Schlaf erkannt werden. Mit unterschiedlichen Verfahren kann Schläfrigkeit auf subjektiver, physiologischer und verhaltensbasierter Ebene identifiziert und quantifiziert werden.Schlafstörungen werden üblicherweise unterschieden nach Dyssomnien (zirkadiane Rhythmusstörungen, Insomnien und Hypersomnien), Parasomnien und Schlafstörungen bei körperlich/psychiatrischen Erkrankungen.
Pharmakologie der Benzodiazepine: Allosterische Aktivatoren an GABAA‐Rezeptoren
Authors: Bönisch Heinz 
Published: April 2007

AbstractBenzodiazepine und die chemisch nicht verwandten Benzodiazepin‐Analoga wie Zolpidem sind alle Agonisten an der allosterischen Bindungsstelle des GABAA‐Rezeptors. Ihre durch Flumazenil antagonisierbaren Effekte beruhen auf einer Verstärkung der Wirkung von GABA im ZNS, die über den GABAA‐Chloridkanalrezeptor vermittelt wird. Die Benzodiazepin‐Analoga binden, im Unterschied zu den klassischen Benzodiazepinen, nicht an die α2‐Untereinheit des Rezeptors; sie wirken daher praktisch nicht anxiolytisch und muskelrelaxierend. Sie sollen auch ein geringeres Abhängigkeitspotential als Benzodiazepine besitzen. Neben kurz wirksamen Benzodiazepinen sind sie Mittel der Wahl bei der Behandlung von Schlafstörungen.
Melatonin, Melatonin‐Rezeptor‐Agonisten und Tryptophan als Schlafmittel. Natürlicher Schlaf?
Authors: Steinhilber Dieter 
Published: April 2007

AbstractMelatonin und Melatoninrezeptor‐Agonisten stellen ein interessantes Konzept zur Behandlung von Schlafstörungen dar. Melatoninrezeptor‐Agonisten verkürzen die Einschlafzeit und können die Gesamtschlafzeit verlängern. Die Schlafarchitektur wird durch Melatoningabe offensichtlich nicht verändert. Melatonin übt keinen klassischen hypnotischen Effekt wie Benzodiazepine oder H1‐Antihistaminika aus, sondern fungiert als Hormon, welches die zirkadiane Phase je nach Einnahmezeitpunkt verschiebt. Ob Melatonin direkte hypnotische Effekte besitzt, ist umstritten, es scheint jedoch die Einschlafbereitschaft zu erhöhen. Bisher ergaben sich weder im Tierversuch noch in klinischen Studien Hinweise auf ein Abhängigkeits‐ oder Missbrauchspotenzial. Melatonin ist in Europa nicht als Arzneimittel zugelassen. In den USA wird Melatonin als Nahrungsergänzungsmittel vertrieben. Der MT‐Rezeptoragonist Ramelteon ist den USA bereits zugelassen, in Europa befindet er sich in Phase III der klinischen Prüfung.
Die Früchte der Postgenom‐Analyse: Identifizierung von Risikogenen für Morbus Crohn und Typ‐2‐Diabetes
Authors: Winckler Thomas 
Published: April 2007

AbstractIn zwei großen Genomstudien wurden Mutationen in Genen entdeckt, die an der Prädisposition bzw. Pathogenese von Morbus Crohn und Typ‐2‐Diabetes beteiligt sind.