bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dichroic, Dinuclear μ2‐(η2‐NO)‐Nitrosoaniline‐Bridged Complexes of Rhenium of the Type [{(CO)3Re(μ‐X)}2ONC6H4NR2] (X = Cl, Br, I; R = Me, Et)
Authors: Krinninger Christoph , Högg Christof , Nöth Heinrich , Gálvez Ruiz Juan Carlos , Mayer Peter , Burkacky Ondrej , Zumbusch Andreas , Lorenz Ingo‐Peter 
Published: September 2005

AbstractA series of unusual dinuclear μ2‐(η2‐NO)‐nitrosoaniline‐bridged complexes [{(CO)3Re(μ‐X)}2ONC6H4NR2] (X = Cl, Br, I; R = Me, Et) with dichroic properties have been synthesised by reaction of pentacarbonylhalogenorhenium(I) [(CO)5ReX] (X = Cl, Br, I) with the corresponding nitrosoaniline derivatives R2NC6H4NO (R = Me, Et). The deeply coloured solutions in CH2Cl2 show broad UV/Vis absorptions from 595 to 620 nm depending on the halogen bridges and N substituents. Single crystals of all six compounds exhibit a pronounced linear dichroism. The molecular structures have been determined by single‐crystal X‐ray analyses. All the compounds contain two face‐shared octahedra, with two halogens and one NO ligand as bridges. The NO ligand coordinates in a nonsymmetrical η2‐like fashion with N or O coordination to each Re centre. Therefore, the C‐nitroso group and the planar NC2 moiety of NR2 both lie almost exactly within the symmetry plane of the dinuclear complexes. These complexes belong to the novel and simple class of neutral dinuclear C‐nitroso complexes that include the rare, non‐assisted μ2‐(η2‐NO) ligand function and have only single halogen atoms in bridging positions.
Solid‐Phase Synthesis of Lipidated Peptides
Authors: Lumbierres Maria , Palomo Jose M. , Kragol Goran , Roehrs Sonja , Müller Oliver , Waldmann Herbert 
Published: September 2005

AbstractA new flexible and efficient methodology for the solid‐phase synthesis of lipidated peptides has been developed. The approach is based on the use of previously synthesized building blocks and overcomes the limitations of previously reported methods, since long doubly lipidated peptides can be synthesized by using this route. Furthermore, it was thus possible to prepare a large number of N‐ and H‐Ras peptides bearing a wide range of reporter and/or linking groups—efficient tools for the investigation of biological processes. In terms of efficiency and flexibility this solid‐phase method is superior to the solution‐phase synthesis. It gives pure peptides in multimilligram amounts within a much shorter time and with superior overall yield.
Synthesis and Luminescence Properties of Ag2S and PbS Clusters in Zeolite A
Authors: Leiggener Claudia , Calzaferri Gion 
Published: September 2005

AbstractZeolite A provides a suitable environment to host Ag2S and PbS clusters, so that spectroscopic investigations on very small particles are possible. The Ag2S monomer is colorless and shows photoluminescence at 490 nm with a lifetime of 300 μs, while the absorption and luminescence of Ag4S2 and larger clusters are red‐shifted. The properties of these Ag2S/zeolite A materials depend on the co‐cations. Results for Li+, Na+, K+, Rb+, Cs+, Mg2+, Ca2+, and Sr2+ are reported. Excitation energy transfer between Ag2S and Ag4S2 has been studied in materials containing Ca2+ co‐cations. PbS particles can be prepared by the same method as Ag2S in the cavities of zeolite A. The PbS monomers obtained are yellow and show photoluminescence at 570 nm, with a lifetime of 700 ns.
Molecular Junctions Composed of Oligothiophene Dithiol‐Bridged Gold Nanoparticles Exhibiting Photoresponsive Properties
Authors: Huang Wei , Masuda Gou , Maeda Seisuke , Tanaka Hirofumi , Ogawa Takuji 
Published: September 2005

AbstractThree oligothiophene dithiols with different numbers of thiophene rings (3, 6 or 9) have been synthesized and characterized. The X‐ray single crystal structures of terthiophene 2 and sexithiophene 5 are reported herein to show the exact molecular lengths, and to explain the difference between their UV‐visible spectra arising from the different packing modes. These dithiols with different chain lengths were then treated with 2‐dodecanethiol‐protected active gold nanoparticles (Au‐NPs) by means of in situ thiol‐to‐thiol ligand exchange in the presence of 1 μm gap Au electrodes. Thus the molecular junctions composed of self‐assembled films were prepared, in which oligothiophene dithiol‐bridged Au‐NPs were attached to two electrodes by means of AuS bonded contacts. The morphologies and current–voltage (I–V) characteristics of these films were studied by SEM and AFM approaches, which suggested that the thickness of the films (3–4 layers) varied within the size of one isolated Au‐NP and typical distance‐dependent semiconductor properties could be observed. Temperature dependent I–V measurements for these molecular junctions were performed in which the films served as active elements in the temperature range 6–300 K; classical Arrhenius plots and subsequent linear fits were carried out to give the activation energies (ΔE) of devices. Furthermore, preliminary studies on the photoresponsive properties of these devices were explored at 80, 160, and 300 K, respectively. Physical and photochemical mechanisms were used to explain the possible photocurrent generation processes. To the best of our knowledge, this is the first report in which oligothiophene dithiols act as bridging units to link Au‐NPs, and also the first report about functionalized Au‐NPs exhibiting photoresponse properties in the solid state.
Asymmetric Conjugate Reduction of α,β‐Unsaturated Ketones and Esters with Chiral Rhodium(2,6‐bisoxazolinylphenyl) Catalysts
Authors: Kanazawa Yoshinori , Tsuchiya Yasunori , Kobayashi Kazuki , Shiomi Takushi , Itoh Jun‐ichi , Kikuchi Makoto , Yamamoto Yoshihiko , Nishiyama Hisao 
Published: September 2005

AbstractNew asymmetric conjugate reduction of β,β‐disubstituted α,β‐unsaturated ketones and esters was accomplished with alkoxylhydrosilanes in the presence of chiral rhodium(2,6‐bisoxazolinylphenyl) complexes in high yields and high enantioselectivity. (E)‐4‐Phenyl‐3‐penten‐2‐one and (E)‐4‐phenyl‐4‐isopropyl‐3‐penten‐2‐one were readily reduced at 60 °C in 95 % ee and 98 % ee, respectively, by 1 mol % of catalyst loading. (EtO)2MeSiH proved to be the best hydrogen donor of choice. tert‐Butyl (E)‐β‐methylcinnamate and β‐isopropylcinnamate could also be reduced to the corresponding dihydrocinnamate derivatives up to 98 % ee.
Atropisomeric property of 1‐(2,6‐difluorobenzyl)‐3‐[(2R)‐amino‐2‐phenethyl]‐5‐(2‐fluoro‐3‐methoxyphenyl)‐6‐methyluracil
Authors: Tucci Fabio C. , Hu Tao , Mesleh Michael F. , Bokser Allan , Allsopp Eric , Gross Timothy D. , Guo Zhiqiang , Zhu Yun‐Fei , Struthers R. Scott , Ling Nicholas , Chen Chen 
Published: September 2005

Abstract1‐(2,6‐Difluorobenzyl)‐3‐[(2R)‐amino‐2‐phenethyl]‐5‐(2‐fluoro‐3‐methoxyphenyl)‐6‐methyluracil (6), a potent and orally active antagonist of the human gonadotropin‐releasing hormone receptor, exists as a pair of atropisomers in solution, which was detected by NMR spectroscopy, and separable by HPLC. In addition to a (R)‐configured benzylamine, there is a second stereogenic element due to the presence of a chiral axis between the substituted 5‐phenyl group and the uracil core. The rate constant of the interconversion (k = 5.07 × 10−5 s−1) of these two atropisomers was determined by proton NMR analysis of a diastereoisomer‐enriched sample in aqueous solution at 25°C, and the corresponding Gibbs free energy ΔG# of rotation barrier (97.4 kJ mol−1) was calculated using the Eyring equation. The diastereoisomer half‐life at physiological temperature (37°C) in aqueous media was estimated to be about 46 min. © 2005 Wiley‐Liss, Inc. Chirality 17:559–564, 2005.
Optical resolution by crystallization from melt using enantiomer derivatives as resolving agents: Nonlinear behavior of resolving agent mixtures
Authors: Schindler József , Egressy Márton , Bálint József , Hell Zoltán , Fogassy Elemér 
Published: September 2005

AbstractSubstituted racemic 1‐phenylethylamine derivatives were reacted in molten phase with chiral N‐substituted 1‐phenylethylamine dicarboxylic acid derivatives (4–9), and their mixtures (e.g., 4+6, 7+8, etc.) in different ratios, and the crystalline quasi‐racemic diastereomers so formed were separated. Nonlinear behavior of the mixtures of resolving agents having related structure and considerable positive and negative chiral–chiral interactions were observed. © 2005 Wiley‐Liss, Inc. Chirality 17:565–569, 2005.
Evaluation of chiral discrimination of highly negatively charged enantiomers by quaternary ammonium β‐cyclodextrin using 1H NMR
Authors: Liu Qinfeng , Viranga Tillekeratne L.M. , Kim Yong‐Wah , Kirchhoff Jon R. , Hudson Richard A. 
Published: September 2005

AbstractThe positively charged quaternary ammonium cyclodextrin, QA‐β‐CD, was previously used as a chiral selector to achieve baseline resolution of two of the dianionic enantiomers of disodium 3‐(p‐isothiocyanatophenoxy)‐3‐(p‐isothiocyanatophenyl)propane‐1,2‐disulfate by capillary electrophoresis. The basis of the chiral discrimination between QA‐β‐CD and the enantiomers was investigated by 1H NMR spectroscopy. COSY and NOESY spectra were used to infer the role that molecular interactions and the stereocenters have upon association of QA‐β‐CD with the enantiomers. A parallel two‐step complexation model is used to rationalize the NMR and the chiral discrimination observed during separation of the enantiomers. © 2005 Wiley‐Liss, Inc. Chirality 17:570–576, 2005.
Computational study of conformational and chiroptical properties of (2R,3S,4R)‐(+)‐3,3′,4,4′,7‐flavanpentol
Authors: Cappelli Chiara , Bronco Simona , Monti Susanna 
Published: September 2005

AbstractConformational analysis of (2R,3S,4R)‐(+)‐3,3′,4,4′,7‐flavanpentol, a flavonoid compound displaying both antioxidant and pro‐oxidant properties, is performed by molecular mechanics and density functional theory calculations both in the gas phase and in methanol solution by using the Polarizable Continuum Model. Nine different conformations are identified. Absorption (UV) and circular dichroism (CD) spectra and optical rotations are calculated by means of time dependent density functional theory (TDDFT) and compared with experiments. The effects of a complex environment formed by water and proline‐rich peptide molecules on the conformational characteristics of (2R,3S,4R)‐(+)‐3,3′,4,4′,7‐flavanpentol and therefore on its UV and CD spectra are investigated by atomistic molecular dynamics simulations. © 2005 Wiley‐Liss, Inc. Chirality 17:577–589, 2005.
Role of cyclic AMP response element binding protein in human leukemias
Authors: Shankar Deepa B. , Cheng Jerry C. , Sakamoto Kathleen M. 
Published: September 2005

AbstractAcute myeloid leukemia (AML) in adults has a 20% 5‐year disease‐free survival despite treatment with aggressive cytotoxic chemotherapy. Previous work from our laboratory demonstrated that the majority of patients with acute lymphoid and myeloid leukemia overexpress CREB in the bone marrow. CREB overexpression is associated with poor initial outcome of clinical disease in AML patients. CREB is a transcription factor that functions in glucose homeostasis, growth‐factor‐dependent cell survival, and memory. Signaling by hematopoietic growth factors, such as GM‐CSF, results in activation of CREB and up‐regulation of CREB target genes. To study its role in hematopoiesis, we overexpressed CREB in leukemia cell lines and in mice. CREB overexpression resulted in increased survival and proliferation of myeloid cells and blast‐transformation of bone marrow progenitor cells from transgenic mice expressing CREB in the myeloid lineage. CREB transgenic mice also develop myeloproliferative disease after 1 year. Thus, CREB acts as a protooncogene to regulate hematopoiesis and contributes to the leukemia phenotype. Our results suggest that CREB‐dependent pathways may serve as targets for directed therapies in leukemia in the future. Cancer 2005. © 2005 American Cancer Society.
Anaplastic large cell lymphoma treated with a leukemia‐like therapy
Authors: Rosolen Angelo , Pillon Marta , Garaventa Alberto , Burnelli Roberta , d'Amore Emanuele S. , Giuliano Maria , Comis Margherita , Cesaro Simone , Tettoni Katia , Luisa Moleti Maria , Tamaro Paolo , Visintin Gianluca , Zanesco Luigi 
Published: October 2005

AbstractBACKGROUNDChildhood anaplastic large cell lymphoma (ALCL) is a well defined entity with a rather poor prognosis. Different approaches have been adopted in the treatment of ALCL in various cooperative trials, including short high‐dose intensive therapy and leukemia‐like protocols. In the early 1990s, the Italian Association of Pediatric Hematology and Oncology (AIEOP) initiated a multicenter trial for the treatment of ALCL based on a modified LSA2‐L2 protocol.METHODSThirty‐four consecutive eligible children with newly diagnosed ALCL were enrolled in the AIEOP LNH‐92 protocol. Treatment was comprised of an induction of remission phase, followed by consolidation and maintenance for a total duration of 24 months, independently of disease stage.RESULTSThirty of 34 patients (88%) achieved complete disease remission and 8 patients experienced disease recurrence. With a median follow‐up of 8.4 years, the probabilities of survival and event‐free survival were 85% (range, 79–91%) and 65% (range, 57–73%), respectively. Therapy was well tolerated and hematologic toxicity was the most frequent toxicity.CONCLUSIONSThe leukemia‐like protocol AIEOP LNH‐92 was found to be an effective treatment for childhood ALCL. Its long duration may be beneficial to specific patient subgroups, but optimal treatment duration in ALCL remains to be elucidated. Cancer 2005. © 2005 American Cancer Society.
Projection patterns of gustatory neurons in the suboesophageal ganglion and tritocerebrum of mosquitoes
Authors: Ignell Rickard , Hansson Bill S. 
Published: September 2005

AbstractMosquitoes are heavily dependent on gustatory information when feeding. Following the recent elucidation of the molecular basis of gustation in the malaria mosquito, we present a detailed study of primary central projections of gustatory receptor neurons into the brain in the malaria (Anopheles gambiae) and yellow fever (Aedes aegypti) mosquito. In the brain we provide a detailed map of the areas targeted and describe a number of intrinsic neural elements connecting primary taste areas to higher brain levels. The morphological features described are discussed and compared to earlier reports in other insects as, e.g., the fruitfly, Drosophila. J. Comp. Neurol. 492:214–233, 2005. © 2005 Wiley‐Liss, Inc.
Prefrontal cortex in the rat: Projections to subcortical autonomic, motor, and limbic centers
Authors: Gabbott Paul L.A. , Warner Tracy A. , Jays Paul R.L. , Salway Phillip , Busby Sarah J. 
Published: September 2005

AbstractThis paper describes the quantitative areal and laminar distribution of identified neuron populations projecting from areas of prefrontal cortex (PFC) to subcortical autonomic, motor, and limbic sites in the rat. Injections of the retrograde pathway tracer wheat germ agglutinin conjugated with horseradish peroxidase (WGA‐HRP) were made into dorsal/ventral striatum (DS/VS), basolateral amygdala (BLA), mediodorsal thalamus (MD), lateral hypothalamus (LH), mediolateral septum, dorsolateral periaqueductal gray, dorsal raphe, ventral tegmental area, parabrachial nucleus, nucleus tractus solitarius, rostral/caudal ventrolateral medulla, or thoracic spinal cord (SC). High‐resolution flat‐map density distributions of retrogradely labelled neurons indicated that specific PFC regions were differentially involved in the projections studied, with medial (m)PFC divided into dorsal and ventral sectors. The percentages that WGA‐HRP retrogradely labelled neurons composed of the projection neurons in individual layers of infralimbic (IL; area 25) prelimbic (PL; area 32), and dorsal anterior cingulate (ACd; area 24b) cortices were calculated. Among layer 5 pyramidal cells, approximately 27.4% in IL/PL/ACd cortices projected to LH, 22.9% in IL/ventral PL to VS, 18.3% in ACd/dorsal PL to DS, and 8.1% in areas IL/PL to BLA; and 37% of layer 6 pyramidal cells in IL/PL/ACd projected to MD. Data for other projection pathways are given. Multiple dual retrograde fluorescent tracing studies indicated that moderate populations (<9%) of layer 5 mPFC neurons projected to LH/VS, LH/SC, or VS/BLA. The data provide new quantitative information concerning the density and distribution of neurons involved in identified projection pathways from defined areas of the rat PFC to specific subcortical targets involved in dynamic goal‐directed behavior. J. Comp. Neurol. 492:145–177, 2005. © 2005 Wiley‐Liss, Inc.
Direct time integration of rigid body motion with discrete‐impulse midpoint approximation: explicit Newmark algorithms
Authors: Krysl P. 
Published: October 2005

AbstractWe address time integration of computational mechanical models where the evaluation of the forcing is expensive (molecular dynamics, for example), and hence we investigate integrators that are explicit in the forcing evaluations. The point of departure is the midpoint rule, either in the classical form for the vector space setting, or the Lie form for the rotation group. By introducing discrete, concentrated impulses we approximate the forcing imparted to the system over the time step, and thus we formulate two adjoint explicit first‐order integrators. These may be composed to yield a second‐order integrator which inherits the good properties of the first‐order integrators, in our case symplecticity and momentum conservation. Thus, we get the classical Newmark algorithm for translational motion (vector space dynamics), or the rotation‐group counterpart of the vector space integrator, which we call the explicit midpoint Lie Newmark algorithm. Enunciation of the parallels between these two algorithms is the main accomplishment of this contribution. Copyright © 2005 John Wiley & Sons, Ltd.
New tools for visualization and analysis of morphogenesis in spherical embryos
Authors: Tyszka J. Michael , Ewald Andrew J. , Wallingford John B. , Fraser Scott E. 
Published: September 2005

AbstractMany classical models of development, including amphibians, fish, and echinoderms, have embryos that are approximately spherical and contain concentric cell layers during early development. Neighbor relationships in such curved cell layers are not conveniently assayed or measured by conventional physical or optical sectioning techniques. To answer these challenges, we have constructed computational methods that correct for spherical distortion in 2D images and that allow extraction of concentric cell layers from 3D digital images. These methods for quantitative analysis and visualization of early development in spherical embryos are introduced by using them for the quantitative analysis of 2D and 3D images of gastrula stage Xenopus laevis. Developmental Dynamics 234:974–983, 2005. © 2005 Wiley‐Liss, Inc.
Transient natural convection of low‐Prandtl‐number fluids in a differentially heated cavity
Authors: Mohamad A. A. , Viskanta R. 
Published: October 2005

AbstractThe transient convective motion in a two‐dimensional square cavity driven by a temperature gradient is analysed. The cavity is filled with a low‐Prandtl‐number fluid and the vertical walls are maintained at constant but different temperatures, while the horizontal boundaries are adiabatic. A control volume approach with a staggered grid is employed to formulate the finite difference equations. Numerically accurate solutions are obtained for Prandtl numbers of 0·001, 0·005 and 0·01 and for Grashof numbers up to 1 × 107. It was found that the flow field exhibits periodic oscillation at the critical Grashof numbers, which are dependent on the Prandtl number. As the Prandtl number is decreased, the critical Grashof number and the frequency of oscillation decrease. Prior to the oscillatory flow, steady state solutions with an oscillatory transient period were predicted. In addition to the main circulation, four weak circulations were predicted at the corners of the cavity.
A new approach to potential flow around axisymmetric bodies
Authors: Yücel Nuri̇ , Altaç Zekeri̇ya 
Published: October 2005

AbstractA new method is introduced to solve potential flow problems around axisymmetric bodies. The approach relies on expressing the infinite series expansion of the Laplace equation solution in terms of a finite sum which preserves the Laplace solution for the potential function under a Neumann‐type boundary condition. Then the coefficients of the finite sum are calculated in a least squares approximation sense using the Gram‐Schmidt orthonormalization method. Sample benchmark problems are presented and discussed in some detail. The solutions are accurate and converged faster when a rather small number of terms were used. The method is simple and can be easily programmed.
Numerical methods for water‐wave radiation problems
Authors: Liapis Stergios 
Published: October 2005

AbstractA boundary integral equation method is used to compute the forces acting on bodies oscillating at or near the free surface of a fluid. This method relies on the use of a Green function representing the potential of a unit pulsating source beneath the free surface. A peculiarity of the boundary integral equation method in the presence of a free surface is that it breaks down at certain characteristic frequencies also known as ‘irregular frequencies’. The objectives of the present study are to develop simple and efficient algorithms for the numerical evaluation of the Green function as well as a method for removing the irregular frequencies. In particular, systematic expansions for the Green function have been developed. These algorithms are very efficient and remarkably simple to implement numerically. In order to remove the irregular frequencies, the boundary integral equation is supplemented by the first N null‐field equations. As a result the first N irregular frequencies are eliminated. This method introduces a very small additional computational cost and is general enough so that it can be applied to any free surface problem.
Unsteady supersonic flow over an oscillatory aerofoil using a second‐order TVD scheme
Authors: Kim Jae‐Soo 
Published: October 2005

AbstractThe unsteady flow over an oscillatory NACA0012 aerofoil has been simulated by the calculation with Euler equations. The equations are discretized by an implicit Euler in time, and a second‐order space‐accurate TVD scheme based on flux vector splitting with van Leer's limiter. Modified eigenvalues are proposed to overcome the slope discontinuities of split eigenvalues at Mach = 0·0 and ± 1·0, and to generate a bow shock in front of the aerofoil. A moving grid system around the aerofoil is generated by Sorenson's boundary fitted co‐ordinates for each time step. The calculations have been done for two angles of attack θ = 5·0° sin (ωt) and θ = 3·0° + 3·0° sin (ωt) for the free‐stream Mach numbers 2·0 and 3·0. The results show that pressure and Mach cells flow along characteristic lines. To examine unsteady effects, the responses of wall pressure and normal force coefficients are analysed by a Fourier series expansion.
An integrated modelling system for coastal area dynamics
Authors: Klevanny K. A. , Matveyev G. V. , Voltzinger N. E. 
Published: October 2005

AbstractTwo‐dimensional initial‐boundary value problems are considered for the shallow water equations and the equation of advection and dispersion of pollutants. The problems are solved in curvilinear boundary fitted co‐ordinates. The transformed equations are integrated on a regular grid by the semi‐implicit and implicit finite difference methods. Based on the numerical method, the integrated modelling system Cardinal for coastal area dynamics and pollution processes is developed for application on personal computers. Examples of computations are given.