bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surface‐enhanced Raman scattering studies on chemically transformed carbon nanotube thin films
Authors: Lefrant S. , Baltog I. , Baibarac M. 
Published: July 2005

AbstractWe review our experimental data obtained by Raman spectroscopy on single‐walled carbon nanotubes (SWNTs) using surface‐enhanced Raman scattering (SERS). We focused on the study of the dependence of the SERS spectra of SWNTs on both the rough metallic substrate type and the film thickness. In particular, we show that degradation of the nanotubes, mainly metallic, occurs for very thin films with the formation of graphitic, fullerene‐like or amorphous carbon particles. We show also that SWNTs reacting with H2SO4 form a salt of the hydrogensulfate type similar to that resulting from graphite–H2SO4 interaction. SWNTs exhibit a complicated spectroelectrochemical behavior in aqueous and non‐aqueous H2SO4 solutions that depends also on the sweep potential range. We demonstrate that the oxidation–reduction processes have a quasi‐reversible or irreversible character. Finally, SERS studies on compressed SWNTs in different host matrices, inorganic and organic, reveal nanotube breaking and that tube fragments may react or not with the host matrix used. Copyright © 2005 John Wiley & Sons, Ltd.
Genetic studies on several bean traits of Coffea canephora coffee in Cameroon
Authors: Cilas Christian , Bouharmont Pierre 
Published: July 2005

AbstractThe genetic parameters of several bean traits of coffee from the species Coffea canephora were estimated using two mating designs: a triangular diallel with 6 parents and a partial diallel with 18 parents. The traits studied were: normal bean weight, the percentage of peaberries, the length, width and thickness of the beans. These characteristics were studied along with yield. The yield data came from harvests obtained over 14 years divided into an initial cycle of 6 years, a second cycle of 5 years after cutting back and a third cycle of 3 years after topping. The general combining abilities (GCA) were the principal sources of significant variation for the traits studied. Transmission of these traits was therefore mostly additive. Yield over 14 years was the most heritable trait. The rank correlations between the GCA of the bean traits and those of yield were not significant. The genetic correlations estimated in the partial diallel did not reveal any link between bean traits and yield. Only one genetic correlation between the peaberry rate and yield was significant. The peaberry rate was linked to fertility, which thus appeared to be a genetic component of yield. Index‐based selection combining an increase in yield with improved bean traits could therefore be carried out without any particular difficulty. Copyright © 2005 Society of Chemical Industry
Multidetector row computed tomography for diagnosing intraductal extension of breast carcinoma
Authors: Fujita Takeo , Doihara Hiroyoshi , Takabatake Daisuke , Takahashi Hirotoshi , Yoshitomi Seiji , Ishibe Yoichi , Ogasawara Yutaka , Shimizu Nobuyoshi 
Published: July 2005

AbstractObjectivesSeveral reports supported the association of higher ipsilateral breast tumor recurrence rates with positive or intermediate margins compared with negative pathologic margins. Precise evaluation of intraductal component and adequate surgical margin are important factors affecting the tumor recurrence after breast conserving surgery. Numerous studies have reported the utility of magnetic resonance imaging for diagnosing developing intraductal extension of breast cancer, but few have investigated multidetector‐row computed tomography (MD‐CT). The present study evaluated the clinical utility of MD‐CT for detecting intraductal extension of breast carcinoma, and analyzed clinical parameters affecting the detection of intraductal extension under MD‐CT.MethodsSubjects comprised 44 patients grouped into three categories according to degree of intraductal extension of the main tumor under MD‐CT (Intraductal spread grade 1∼3: IDS 1∼3). Tumors were also categorized histopathologically (p‐IDS 0∼3), and CT‐pathological correlations were examined retrospectively. Clinical parameters were evaluated to determine the affect on detection of intraductal components.ResultsMD‐CT detected 44 breast lesions (100%). Sensitivity for detection of intraductal component was 81.2%, specificity was 67.8%, and accuracy was 72.7%. Regarding extent of intraductal components, significant correlations were found between histopathological and MD‐CT findings. A strong correlation was found in postmenopausal women between T2 tumor and high histological grade.ConclusionsMD‐CT findings of intraductal extension from breast carcinoma correlate with histological degree of intraductal extension, and MD‐CT may be useful for preoperative assessment of breast‐conserving surgery, particularly for postmenopausal women with histological high nuclear grade and T2 tumor. J. Surg. Oncol. 2005;91:10–16. © 2005 Wiley‐Liss, Inc.
First Aldehyde‐Functionalized Poly(2‐oxazoline)s for Chemoselective Ligation
Authors: Taubmann Christian , Luxenhofer Robert , Cesana Sonia , Jordan Rainer 
Published: July 2005

AbstractSummary: A protected aldehyde‐functionalized 2‐oxazoline, 2‐[3‐(1,3)‐dioxolan‐2‐ylpropyl]‐2‐oxazoline (DPOx), was synthesized from commercially available compounds in high yields. The polymerization of DPOx with different initiators proceeds via a living ionic mechanism; thus, the polymers were of low polydispersity and the degree of polymerization could be precisely adjusted. Copolymerization with 2‐methyl‐2‐oxazoline gave water‐soluble statistical copolymers. Hydrolysis of the homo‐ and copolymers resulted in well‐defined, aldehyde‐bearing poly(2‐oxazoline)s. The aldehyde side functions reacted quantitatively with an amino‐oxy compound to form the corresponding oxime.
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Fracture behaviors of silane‐cured metallocene‐catalyzed polyethylene thermoplastic vulcanizate
Authors: Lai S.‐M. , Wu T.‐H. 
Published: July 2005

AbstractSilane moisture‐cured metallocene‐catalyzed polyethylene (mPE) blend to form a novel thermoplastic vulcanizate (TPV) has been prepared. Metallocene polyethylenes with two different levels of comonomer contents were grafted with various amounts of vinyltriethoxy silane. As a result, tensile strength varies slightly with increasing the levels of silane concentrations, at all test temperatures. Tear strength generally decreases with reduced energy dissipation, at higher degrees of cure. “Threshold” fracture energy is roughly proportional to the reciprocal square root of Young's modulus. By relating tensile strength to tear strength, it was found that the corrected average depth of flaw is in the range of 29.3 ± 7.2 μm, which successfully confirms the extension of Rivlin and Thomas's theory for conventional elastomers to TPVs under an elaborate treatment, due to the limitation of the theory. Cutting strength of mPE TPVs gives an intermediate value when compared with that of crystalline plastics and conventional elastomers, which further signifies the importance of crystalline yielding even in the nanofracture zone of deformation. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2207–2218, 2005
Insecticidal and fungicidal activity of new synthesized chitosan derivatives
Authors: Rabea Entsar I , Badawy Mohamed EI , Rogge Tina M , Stevens Christian V , Höfte Monica , Steurbaut Walter , Smagghe Guy 
Published: July 2005

AbstractChitosan, the N‐deacetylated derivative of chitin, is a potential biopolysaccharide owing to its specific structure and properties. In this paper, we report on the synthesis of 24 new chitosan derivatives, N‐alkyl chitosans (NAC) and N‐benzyl chitosans (NBC), that are soluble in dilute aqueous acetic acid. The different derivatives were synthesized by reductive amination and analyzed by 1H NMR spectroscopy. A high degree of substitution (DS) was obtained with N‐(butyl)chitosan (DS 0.36) at a 1:1 mole ratio for NAC derivatives and N‐(2,4‐dichlorobenzyl)chitosan (DS 0.52) for NBC derivatives. Their insecticidal and fungicidal activities were tested against larvae of the cotton leafworm Spodoptera littoralis (Boisduval) (Lepidoptera: Noctuidae), the grey mould Botrytis cinerea Pers (Leotiales: Sclerotiniaceae) and the rice leaf blast Pyricularia grisea Cavara (Teleomorph: Magnaporthe grisea (Hebert) Barr). The oral feeding bioassay indicated that all the derivatives had significant insecticidal activity at 5 g kg−1 in artificial diet. The most active was N‐(2‐chloro‐6‐fluorobenzyl)chitosan, which caused 100% mortality at 0.625 g kg−1, with an estimated LC50 of 0.32 g kg−1. Treated larvae ceased feeding after 2–3 days; the mechanism of action remains unknown. In a radial hyphal growth bioassay with both plant pathogens, all derivatives showed a higher fungicidal action than chitosan. N‐Dodecylchitosan, N‐(p‐isopropylbenzyl)chitosan and N‐(2,6‐dichlorobenzyl)chitosan were the most active against B cinerea, with EC50 values of 0.57, 0.57 and 0.52 g litre−1, respectively. Against P grisea, N‐(m‐nitrobenzyl)chitosan was the most active, with 77% inhibition at 5 g litre−1. The effect of different substitutions is discussed in relation to insecticidal and fungicidal activity. Copyright © 2005 Society of Chemical Industry
Understanding strongly correlated many‐body systems with quantum Monte Carlo simulations
Authors: Lavalle Catia , Rigol Marcos , Muramatsu Alejandro 
Published: July 2005

AbstractOur understanding of the physical properties of quantum many‐particle systems relies normally on the identification of elementary excitations that can be considered as weakly interacting building blocks of the whole system. In systems characterized by the presence of strong interactions between the elementary components, like high‐temperature superconductors and related materials or like ultra‐cold atoms in optical lattices, well known theoretical techniques like mean‐field or perturbation theories fail. On the contrary, quantum Monte Carlo simulations allow to handle such systems in a “numerically exact” way. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Field‐induced effects in the S = 1 two‐dimensional Heisenberg antiferromagnet
Authors: Gouvêa M. E. , Pires A. S. T. 
Published: July 2005

AbstractWe use the self‐consistent harmonic approximation to study the spin S = 1 Heisenberg antiferromagnet on a two‐dimensional lattice in a uniform applied magnetic field. The magnetic field destroys the 𝒪(3) symmetry and an XY‐like behavior, with a Berezinskii–Kosterlitz–Thouless (BKT) transition, is expected. We obtain the field dependence of the transition temperature for fields varying in a wide range. There has been experimental evidence that, for low dimensional spin systems, a gap can be induced by the applied magnetic field. We also investigate the behavior of this field‐induced gap. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nonlinear optical properties of ionic NLO chromophores: An attempt to bridge the gap between computation and experiment
Authors: Sainudeen Zuhail , Ray Paresh Chandra 
Published: July 2005

AbstractWe present a quantum chemical analysis of the molecular structure and first hyperpolarizabilities of a series of stilbazolium ions and compare their results with corresponding neutral molecules. The molecular geometries are obtained via B3LYP/6‐31G** optimization, including the self‐consistent reaction field/polarizable continuum model (SCRF/PCM) approach. The static first hyperpolarizabilities (β0) are calculated using the ab initio coupled perturbed Hartree–Fock (CPHF) method, while the dynamic first hyperpolarizability (β) is investigated using the ZINDO/correction vector (CV) method, including solvent effects. The effects of donor–acceptor properties, solvent polarity, the dispersion effect, and aggregation on the first hyperpolarizibility are methodically evaluated with an attempt toward developing the engineering guidelines for the enhancement of the molecular optical nonlinearities of charged chromophores. We compare our theoretical results with the experimental values wherever available in the literature and evaluate the results in detail about the agreements and disagreements between theoretical and experimental findings. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Density functional theory study of the origin of IR and Raman band shifts in H‐bond complexes of triethylamine with water
Authors: Zhanpeisov N. U. , Ohta K. , Kajimoto S. , Hobley J. , Hatanaka K. , Fukumura H. 
Published: July 2005

AbstractThe present article discusses the results of density functional calculations obtained using B3LYP functional and the standard 6‐31G* basis sets for mono‐, di‐, and triethylamines (MEA, DEA, and TEA, respectively) and their H‐bonded complexes with water molecules. In particular, the origin of the observed experimentally clear red shift for methylene νCHmode due to the nanosecond laser T‐jump in TEA/H2O system is validated theoretically by explicit consideration of related infrared (IR) and Raman peaks appeared at the CH absorbance region. All theoretical calculations were performed with full geometry optimizations without imposing any constraints, and followed by direct harmonic frequency calculations. The effects of nonspecific and specific solvations were accounted for using simple Onsager model and explicit water molecules. It was shown that the former continuum model does not strongly perturb the observed spectral changes in the CH region because of shallow potential energy surface for the interacting subsystems. Both the structural changes in geometry and electron redistribution as a result of H‐bonding were found to be main factors to explain the observed experimental spectral changes in IR and Raman spectra. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Time‐dependent density functional theory (TD‐DFT) study of the excited state proton transfer in hypoxanthine
Authors: Shukla M. K. , Leszczynski Jerzy 
Published: July 2005

AbstractTheoretical investigations on the ground‐ and excited‐state proton transfer in the isolated and monohydrated forms of hypoxanthine have been performed. Ground‐ and transition‐state geometries were optimized at the Hartree–Fock (HF)/6‐311++G(d,p) and B3LYP/6‐311++G(d,p) levels. The geometries of tautomers including the transition states were also optimized in the lowest singlet ππ* excited state at the CIS/6‐311++G(d,p) level. The time‐dependent density function theory augmented with B3LYP functional (TD‐B3LYP) and the 6‐311++G(d,p) basis set were used to compute vertical transition energies using the B3LYP geometries. The TD‐B3LYP/6‐311++G(d,p) calculations were also performed using the CIS/6‐311++G(d,p) geometries to predict the adiabatic transition energies of tautomers and the excited‐state proton transfer barrier heights. The effect of aqueous environments was considered using the polarizable continuum model (PCM). The harmonic vibrational frequency calculations were performed to ascertain the nature of potential energy surfaces. It was found that proton transfer is characterized by a high barrier height both in the gas phase and in aqueous solution. The explicit inclusion of a water molecule in the proton transfer path reduces the barrier height drastically. The excited‐state barrier height was found to be increased as compared with that in the ground state. The transition states corresponding to the proton transfer from the keto to the enol form for the monohydrated forms were found to have a zwitterionic structure. The zwitterionic nature of the hydrated transition‐state structure is increased in the excited state. The transition‐state geometries are more easily expressed in the form of H3O+…HX− for the monohydrated complex of the molecule. The excited‐state geometries, including that of transition states, were found to be largely nonplanar. The nonplanar fragment was localized mostly in the six‐membered ring. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Molecular modeling study of binding to the catalytic site of PDE4 enzymes by a novel class of inhibitors
Authors: Lawrenz Morgan E. , Salter E. A. , Wierzbicki Andrzej , Thompson W. J. 
Published: July 2005

AbstractCyclic nucleotide phosphodiesterases (PDEs) comprise a superfamily of enzymes that hydrolyze the second messengers adenosine and guanosine 3′,5′‐cyclic monophosphate (cAMP and cGMP) to their noncyclic nucleotides (5′‐AMP and 5′‐GMP). Selective inhibitors of all 11 gene families of PDEs are being sought based on the different biochemical properties of the different isoforms, including their substrate specificities. The PDE4 gene family consists of cAMP‐specific isoforms; selective PDE4 inhibitors such as rolipram have been developed, and related agents are used clinically as anti‐inflammatory agents for asthma and COPD. The known crystal structures of PDE4 bound with rolipram and IBMX have allowed us to define plausible binding orientations for a novel class of benzylpyridazinone‐based PDE4 inhibitors represented by EMD 94360 and EMD 95832 that are structurally distinct from rolipram. Molecular mechanics modeling with autodocking is used to explore energetically favorable binding orientations within the PDE4 catalytic site. We present two putative orientations for EMD 94360/95832 inhibitor binding. Our estimated interaction energies for rolipram, IBMX, EMD 94360, and EMD 95832 are consistent with the experimental data for their IC50 values. Key binding residues and interactions in these orientations are identified and compared with known binding motifs proposed for rolipram. The experimentally observed improved strength of inhibition exhibited by this novel class of PDE4 inhibitors is explained by the molecular modeling reported here. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Do-it-yourself type theory
Authors: Backhouse Roland , Chisholm Paul , Malcolm Grant , Saaman Erik 
Published: July 2005

Abstract
This paper provides a tutorial introduction to a constructive theory of types based on, but incorporating some extensions to, that originally developed by Per Martin-Löf. The emphasis is on the relevance of the theory to the construction of computer programs and, in particular, on the formal relationship between program and data structure. Topics discussed include the principle of propositions as types, free types, congruence types, types with information loss and mutually recursive types. Several examples of program development within the theory are also discussed in detail.
VVSL: A language for structured VDM specifications
Authors: Middelburg C. A. 
Published: July 2005

Abstract
VVSL is a VDM specification language of the “British School” with modularisation constructs allowing sharing of hidden state variables and parameterisation constructs for structuring specifications, and with constructs for expressing temporal aspects of the concurrent execution of operations which interfere via state variables. The modularisation and parameterisation constructs have been inspired by the “kernel” design language COLD-K from the ESPRIT project 432: METEOR, and the constructs for expressing temporal aspects by various temporal logics based on linear and discrete time. VVSL is provided with a well-defined semantics by defining a translation to COLD-K extended with constructs which are required for translation of the VVSL constructs for expressing temporal aspects.
In this paper, the syntax for the modularisation and parameterisation constructs of VVSL is outlined. Their meaning is informally described by giving an intuitive explanation and by outlining the translation to COLD-K. It is explained in some detail how sharing of hidden state variables is modelled. Examples of the use of the modularisation and parameterisation constructs are also given. These examples are based on a formal definition of the relational data model. With respect to the constructs for expressing temporal aspects, the ideas underlying the use of temporal formulae in VVSL are briefly outlined and a simple example is given.
Event fairness and non-interleaving concurrency
Authors: Kwiatkowska Marta Z. 
Published: July 2005

Abstract
Event fairness suitable for non-interleaving concurrency is proposed. Fairness is viewed with respect to concurrency, rather than non-determinism, in the sense that no concurrent component of the system should be delayed indefinitely. Shields' asynchronous transition systems and Mazurkiewicz's traces have been used; the model gives rise to a partial order. A class of generalised notions of (weak, strong and unconditional) event fairness relative to progress requirements is derived. The weakest fairness notion in this class is shown to coincide with maximality with respect to the partial order over traces.
Process simulation and refinement
Authors: Jifeng He 
Published: July 2005

Abstract
In this paper we deal with the problem of (nondeterministic and parallel) process refinement. The basic notion of refinement is defined via the improved failure semantics of CSP [BHR84, BrR85, Hoa85, Ros88]. The concept of simulation of Communicating Systems introduced in [Mil80, Par81] is generalised and proved to be sound for the correctness of refinement. A Galois connection is presented to show that up-simulation and down-simulation together provide a complete proof method. The paper also suggests that simulation can be employed to derive an implementation from a specification.
A functional programming approach to the specification and verification of concurrent systems
Authors: Dybjer Peter , Sander Herbert P. 
Published: July 2005

Abstract

Networks of communicating processes can be viewed as networks of stream transformers and programmed in a lazy functional language. Thus the correctness of concurrent systems can be reduced to the correctness of functional programs. In this paper such correctness is proved formally in the
μ
-calculus extended with recursion equations for functional programs. The
μ
-calculus is chosen since it allows the definition of properties by least fixed points (induction) as well as by greatest fixed points (coinduction), and since greatest fixed points are useful for formalising properties, such as fairness, of infinitely proceeding programs. Moreover, non-deterministic processes are represented as incompletely specified deterministic processes, that is, as properties of stream transformers. This method is illustrated by proving the correctness of the alternating bit protocol.
Refinement concepts formalised in higher order logic
Authors: Back R. J. R. , von Wright J. 
Published: July 2005

Abstract
A theory of commands with weakest precondition semantics is formalised using the HOL proof assistant system. The concept of refinement between commands is formalised, a number of refinement rules are proved and it is shown how the formalisation can be used for proving refinements of actual program texts correct.
The fixed point theory of unbounded non-determinism
Authors: Barrett Geoff 
Published: July 2005

AbstractThis paper presents a fixed point theorem for the infinite traces model of CSP. Unlike any other model of CSP, there is no complete partial order over the infinite traces model whose fixed point theory agrees with the operational semantics (A. W. Roscoe, Oxford University Computing Laboratory Technical Monograph PRG-67, 1988). This arises from the introduction of unbounded non-determinism. However, the subset of pre-deterministic processes, that is those which describe the behaviour of a process on some run of its implementation, do form a subset for which the usual order is complete. By requiring that each CSP operator has a monotonic implementation which preserves pre-determinism, it is possible to show that all CSP operators have a least fixed point. In effect, it is the requirement that all operators have a methodical implementation.