bluuebunny/crossref_metadata_2025 huggingface dataset:
Immunosurveillance is active in colorectal cancer as downregulation but not complete loss of MHC class I expression correlates with a poor prognosis
Authors: Watson Nicholas F.S. , Ramage Judith M. , Madjd Zahra , Spendlove Ian , Ellis Ian O. , Scholefield John H. , Durrant Lindy G.
Published: July 2005

Many colorectal tumors lose or downregulate cell surface expression of MHC class I molecules conferring resistance to T‐cell‐mediated attack. It has been suggested that this phenomenon is due to in vivo immune‐tumor interactions. However, evidence of the impact of MHC class I loss on outcomes from colorectal cancer is scarce. In our study of more than 450 colorectal cancers in tissue microarray format, we have shown that both high levels of MHC class I expression and absent MHC class I expression are associated with similar disease‐specific survival times, possibly due to natural killer cell‐mediated clearance of MHC class I‐negative tumor cells. However, tumors with low level expression of MHC class I were found to confer a significantly poorer prognosis, retaining independent significance on multivariate analysis. The existence of these poor prognosis tumors, which may avoid both NK‐ and T‐cell‐mediated immune surveillance, has important implications for the design of immunotherapeutic strategies in colorectal cancer. © 2005 Wiley‐Liss, Inc.
Episode sensitivity in association with process indicators in the Finnish breast cancer screening program
Authors: Sarkeala Tytti , Hakama Matti , Saarenmaa Irma , Hakulinen Timo , Forsman Hakan , Anttila Ahti
Published: July 2005

We assessed the episode sensitivity of the Finnish mammography program for women aged 50–59 (partly 60–64) years and explored associations between the episode sensitivity and the screening process indicators from 1991 to 1999. For the study period, data were available from 10 screening centers. Records of 721,000 screening visits were linked to the files of the nationwide Finnish Cancer Registry from 1991 to 2001 at an individual level. The rates of screen‐detected and interval breast cancers were calculated at the first and at the subsequent screens. The episode sensitivity was determined by contrasting the incidence of interval cancers with the expected population incidence rate without screening (incidence method) and as a proportion of interval cancers out of all cancers detected (detection method). At the subsequent screens, the episode sensitivity determined by the incidence method was 54% and by the detection method 65%. The sensitivity 0–11 and 12–23 months after the screening was 70% and 38%, respectively. The episode sensitivity decreased toward the end of the study period and increased with age. The center‐specific sensitivity increased 13% per 1% absolute increase in the recall rate. In general, our study provides further information on the effectiveness of screening programs. The sensitivity estimates were comparable with those from other European service screening programs. The variability in the episode sensitivity suggests potential for variations in the future screening outcome. © 2005 Wiley‐Liss, Inc.
Detailed analysis of single‐molecule surface‐enhanced resonance Raman scattering spectra of Rhodamine 6G obtained from isolated nano‐aggregates of colloidal silver
Authors: Šašić Slobodan , Itoh Tamitake , Ozaki Yukihiro
Published: July 2005

Surface‐enhanced resonant Raman scattering (SERRS) spectra of Rhodamine 6G (R6G) were acquired from single (aggregated) Ag colloidal particles that had been incubated with various amounts of R6G (0.1–125 nM). The spectra were investigated in detail and the evidence for a single‐molecule‐like response was found even for R6G:Ag particle ratios greatly exceeding equimolarity. After a thorough comparison with literature data, it is concluded that it is reasonable to expect a single‐molecule‐like response even for fairly ‘high’ R6G concentrations. A series of Raman images are shown and commented on with respect to bulk SERRS measurements. The problem of band assignment of single‐molecule spectra of biological species is addressed. Copyright © 2005 John Wiley & Sons, Ltd.
Resonant charge transfer on the nanoscale: studying doublet states of adsorbates by surface‐enhanced Raman scattering
Authors: Arenas J. F. , López‐Tocón I. , Castro J. L. , Centeno S. P. , López‐Ramírez M. R. , Otero J. C.
Published: July 2005

This paper summarizes a series of results where the main role of the charge‐transfer (CT) mechanism in the surface‐enhanced Raman scattering (SERS) of aromatic molecules is demonstrated. This mechanism consists on a photoinduced CT process between nanostructures of the metallic surface and the adsorbed molecules, giving rise to the transient formation of a radical anion of the adsorbate. A general methodology to detect the CT process in SERS is described. It is demonstrated that the SERS features are determined by the differences between the electronic properties of the neutral and the anionic molecular species. On the basis of these results, we propose to use SERS as a tool to characterize such doublet states. Copyright © 2005 John Wiley & Sons, Ltd.
An in situ reduction method for preparing novel surface‐enhanced Raman scattering substrates
Authors: Li Xiaoling , Wang Yanfei , Jia Huiying , Song Wei , Zhao Bing
Published: July 2005

Surface‐enhanced Raman scattering (SERS)‐active substrates with high enhancement were prepared by an in situ reduction method. First, NH2OH·HCl was added as complexing agent to AgNO3 solution, then NaI was dropped in to produce an AgI colloid. Second, the self‐assembly technique was used to transfer the AgI nanoparticles on to the solid substrate and then they were reduced in situ. The UV–visible spectra show that the absorption band is asymmetric, indicating that the Ag nanoparticle size distribution on the substrate is wide, which was further confirmed by atomic force microscopy (AFM) measurements. The SERS‐active substrates with different coverages can be formed in a layer‐by‐layer electrostatic assembly by exposing positively charged surfaces to colloid solutions containing oppositely charged AgI nanoparticles. The results of AFM and UV–visible spectroscopy show that the Ag nanoparticles grow with increase in the degree of coverage and that most of them remain isolated even at high coverage. Consequently, the surface optical properties are dominated by the absorption due to the isolated Ag nanoparticles. The new substrate presents high SERS enhancement and the SERS enhancement factor was estimated to be 109. By comparison with our previous work, the important effects of stabilizers on the formation and transfer of nanoparticles are confirmed. Copyright © 2005 John Wiley & Sons, Ltd.
SERS study of hydrogen peroxide electroreduction on a Pb‐modified Au electrode
Authors: Li Xiao , Gewirth Andrew A.
Published: July 2005

The mechanism of the electroreduction of H2O2 on a Pb‐modified Au surface was examined by surface‐enhanced Raman spectroscopy. The measurements show the presence of lead peroxide, PbOOH+, with the maximum intensity at potential just positive of underpotentially deposited Pb, and bimetallic dihydroxide, AuPb(OH)2, at potential just positive of that where peroxide is reduced and Pb islands maximally formed on the surface. All the modes for these two species decay rapidly and even disappear as the reduction current flows. Both species are absent in solutions not containing either Pb2+ or H2O2. The edge of Pb islands on the Au surface is thus shown to be the active site for this catalysis process. These results further underscore the important role of MOH species in the peroxide electroreduction reaction. Copyright © 2005 John Wiley & Sons, Ltd.
Surface‐enhanced Raman scattering for medical diagnostics and biological imaging
Authors: Vo‐Dinh Tuan , Yan Fei , Wabuyele Musundi B.
Published: July 2005

We present recent development and applications of a surface‐enhanced Raman scattering (SERS) technology for use in medical diagnostics and biological imaging. For medical diagnostics, we use Raman‐active dye‐labeled DNA gene probes and nanostructured metallic substrates as SERS‐active platforms. The surface‐enhanced Raman gene probes can be used to detect DNA biotargets (e.g. gene sequences, bacteria and viral DNA) via hybridization to DNA sequences complementary to these probes. The SERS gene probes eliminate the need for radioactive labels and have great potential to provide both sensitivity, selectivity and label multiplexing for DNA sequencing and clinical assays. We also describe a hyperspectral surface‐enhanced Raman imaging (HSERI) system that combines imaging capabilities with SERS detection to identify cellular components with high spatial and temporal resolution. The HSERI system's application to biological imaging is demonstrated using Raman dye‐labeled silver nanoparticles in cellular systems. Copyright © 2005 John Wiley & Sons, Ltd.
Surface‐enhanced resonance Raman scattering of rhodamine 6G on Pt nanoaggregates
Authors: Kim Nam Hoon , Kim Kwan
Published: July 2005

Platinum aggregates composed of ∼17 nm Pt nanoparticles were found recently to exhibit fairly strong surface‐enhanced Raman scattering (SERS) for adsorbed benzenethiol. In order to broaden its utility as a SERS substrate, the surface‐enhanced resonance Raman scattering (SERRS) effect of these Pt nanoaggregates on Si wafers was examined in this work using rhodamine 6G (R6G) as the probe molecule with 514.5, 568 and 632.8 nm excitation. The SERRS excitation profile appeared to be closely related to the molecular absorption of R6G, implying that the surface enhancement itself would not influence significantly the wavelength dependence of the Raman intensity of R6G on Pt nanoaggregates. The surface roughness was found nonetheless to affect in an obvious manner the enhancement factor (EF) of R6G, eventually showing a levelling off behaviour of SERR intensity with increasing surface roughness. By comparing this with the SERS of benzenethiol, the EF for R6G with 514.5 nm excitation was estimated to be 5 × 104. Copyright © 2005 John Wiley & Sons, Ltd.
Adaptive silver films for surface‐enhanced Raman spectroscopy of biomolecules
Authors: Drachev Vladimir P. , Thoreson Mark D. , Nashine Vishal , Khaliullin Eldar N. , Ben‐Amotz Dor , Davisson V. Jo , Shalaev Vladimir M.
Published: July 2005

The interaction of biological molecules with a typical substrate for surface‐enhanced Raman scattering (SERS) often leads to their structural and functional changes. In this paper we describe SERS substrates, called adaptive silver films (ASFs), in which the biomaterial and the substrate act in concert to produce excellent Raman enhancement through local restructuring of the metal surface while at the same time preserving the properties (such as conformational state and binding activity) of the analyte. These adaptive substrates show great promise for SERS spectroscopy of many different types of biomolecules, and we provide several current examples of their use. Copyright © 2005 John Wiley & Sons, Ltd.
Surface‐enhanced Raman sensors: early history and the development of sensors for quantitative biowarfare agent and glucose detection
Authors: Haynes Christy L. , Yonzon Chanda Ranjit , Zhang Xiaoyu , Van Duyne Richard P.
Published: July 2005

Surface‐enhanced Raman spectroscopy (SERS) is a powerful technique for the sensitive and selective detection of low‐concentration analytes. This paper includes a discussion of the early history of SERS, the concepts that must be appreciated to optimize the intensity of SERS and the development of SERS‐based sensors. In order to achieve the lowest limits of detection, both the relationship between surface nanostructure and laser excitation wavelength, as well as the analyte/surface binding chemistry, must be carefully optimized. This work exploits the highly tunable nature of nanoparticle optical properties to establish the first set of optimization conditions. The SERS enhancement factor, EFSERS, is optimized when the energy of the localized surface plasmon resonance (LSPR) lies between the energy of the excitation wavelength and the energy of the vibrational band of interest. With the narrow LSPRs used in this work, it is straightforward to achieve EFSERS ∼ 108. These optimization conditions were exploited to develop SERS‐based sensors for two important target molecules: a Bacillus anthracis biomarker and glucose in a serum protein mixture. Using these optimized film‐over‐nanosphere surfaces, an inexpensive, portable Raman spectrometer was used successfully to detect the infectious dose of Bacillus subtilis spores with only a 5‐s data collection. The biomarker used to detect the Bacillus subtilis spores binds irreversibly to SERS substrates, whereas other important biomolecules, such as glucose, do not have any measurable binding affinity to a bare silver surface. To overcome this difficulty, a biocompatible partition layer was self‐assembled on the SERS substrate before exposure to the analyte solution. Using the partition layer approach to concentrate glucose near the SERS‐active substrate, physiological glucose concentrations can be detected even in the presence of interfering serum proteins. Copyright © 2005 John Wiley & Sons, Ltd.
Surface‐enhanced Raman spectroscopy: advancements and applications
Authors: Tian Z. Q.
Published: July 2005

Since the mid‐1990s, surface‐enhanced Raman scattering (SERS) has advanced greatly and gained wider application and a renewal of interest. There have been several new and creative developments, e.g. SERS of single molecules, nanostructures and transition metals, tip‐enhanced Raman scattering (TERS), surface‐enhanced hyper‐Raman scattering (SEHRS), ultraviolet‐excited SERS (UV‐SERS) and surface‐enhanced resonance Raman scattering (SERRS), and their wide applications in biology, medicine, materials science and electrochemistry. It is timely to publish a special issue reporting these initiatives and the progress made in the past 7 years. This issue consists of 30 invited articles that are roughly divided into three SERS research themes: theories, methods and applications. These up‐to‐date representatives of the research results clearly show that SERS is important not only for Raman spectroscopy and surface science but also for nanoscience. Copyright © 2005 John Wiley & Sons, Ltd.
Synthesis of Polyacrylonitrile‐block‐Polystyrene Copolymers by Atom Transfer Radical Polymerization
Authors: Lazzari Massimo , Chiantore Oscar , Mendichi Raniero , López‐Quintela M. Arturo
Published: July 2005

Summary: The synthesis of polyacrylonitrile‐block‐polystyrene (PAN‐b‐PS) copolymers by atom transfer radical polymerization (ATRP) is reported. Chain extension of bromine terminated PAN macroinitiators with styrene was performed using a CuBr/N,N,N′,N″,N″‐pentamethyldiethylenetriamine catalyst system and 2‐cyanopyridine as a solvent. The first‐order kinetic plots of styrene consumption showed a significant curvature, indicating a progressive decrease in the concentration of active species during copolymerization. The loss of the bromide end group was mainly ascribed to the elimination of HBr, as shown by 1H NMR spectroscopy. By varying the molar ratio of either the catalyst or the monomer to the initiator, a series of PAN‐b‐PS copolymers were prepared, with polydispersities as low as 1.3, and molar compositions ranging from 8.6/91.4 to 35.5/64.5.

1H NMR spectra of PAN‐b‐PS in DMF‐d7 at 80 °C.

magnified image

1H NMR spectra of PAN‐b‐PS in DMF‐d7 at 80 °C.
Unitary couplings, scattering suboperators and regular factorizations of bounded operator valued functions II
Authors: Boiko S. S. , Dubovoy V. K.
Published: July 2005

In the paper bilateral shifts are studied which generate factorizations of unitary couplings (in the system theory they play the part of channels). Subspaces of L2(𝔎), reducing the multiplication operator by eit, are investigated in the channel language. New criteria for regular divisibility of contractive operator functions in the class L∞ are obtained. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Polyelectrolyte Multilayer Microspheres as Carriers for Bienzyme System: Preparation and Characterization
Authors: Balabushevich Nadezda G. , Sukhorukov Gleb B. , Larionova Natalia I.
Published: July 2005

Summary: Polyelectrolyte multilayer microspheres were prepared by alternating adsorption of dextran sulfate and protamine on melamine formaldehyde cores followed by the partial decomposition of the core. Peroxidase and glucose oxidase were immobilized in the prepared microspheres. Retention of enzymatic activity of the peroxidase/glucose oxidase system incorporated into the microspheres was demonstrated. Applicability of the bienzyme system immobilized in the microspheres for kinetic glucose assay was shown.

SEM image of the polyelectrolyte multilayer microsphere.

magnified image

SEM image of the polyelectrolyte multilayer microsphere.
Phase Transition Behaviors of Self‐Oscillating Polymer and Nano‐Gel Particles
Authors: Sakai Takamasa , Hara Yusuke , Yoshida Ryo
Published: July 2005

Summary: Self‐oscillating polymers and nano‐gel particles consisting of N‐isopropylacrylamide and the ruthenium catalyst of the Belousov‐Zhabotinsky reaction have been prepared. In order to clarify the crosslinking effect on the self‐oscillating behavior, the phase transition behaviors were investigated by measuring the transmittance and the fluorescence intensity of the polymer solution and the gel bead suspension. Cooperative effects due to crosslinking will play an important role for the design of nanoactuators.

Chemical structure of poly(NIPAAm‐co‐Ru(bpy)3).

magnified image

Chemical structure of poly(NIPAAm‐co‐Ru(bpy)3).
Base‐induced 1,4‐elimination:Insights from theory and mass spectrometry*
Authors: Bickelhaupt F. Matthias
Published: July 2005

I.
Introduction
347

II.
Gas‐Phase Ion–Molecule Reactions
348

III.
Scope and Applications of Gas‐Phase Base‐Induced 1,4‐Elimination
349

A.  Anionic and Cationic 1,4‐Elimination
349

B.  Anionic 1,4‐Elimination in an FT‐ICR Cell
350

C.  Anionic 1,4‐Elimination in an FA Flow Tube
351

IV.
Stereochemistry of 1,4‐Elimination
352

A.  Syn Versus Anti Stereochemistry
352

B.  Effect of E Versus Z Stereochemistry of the Substrate
353

V.
Mechanism of 1,4‐Elimination: E1cb Versus E2
353

A.  Base‐Induced 1,4‐Elimination of 1‐Alkoxy‐2‐Butenes
353

B.  Base‐Induced 1,4‐Elimination of 3‐Alkoxycyclohexenes
354

C.  New DFT Computations on Base‐Induced 1,4‐Eliminations
354

VI.
Conclusions and Outlook
358

Acknowledgment
359

References
359

Experimental and theoretical studies on gas‐phase base‐induced 1,4‐elimination reactions are summarized and discussed. The emphasis is on the synergy that is achieved by combining the complementary data from mass spectrometry and theoretical chemistry. The scope and applications of 1,4‐eliminations are discussed and compared with other elementary reactions; e.g., 1,2‐elimination and aliphatic (SN2) and allylic (SN2′) nucleophilic substitution. Furthermore, the syn versus anti stereochemistry of 1,4‐elimination reactions and the effect of E versus Z stereochemistry of the substrate are examined. Particular attention is paid to the mechanistic nature of 1,4‐elimination, i.e., E2 or E1cb, as well as special features such as the single‐well E2 and E1cb mechanism. Also, new results from density functional theory computations (BP86/TZ2P) are presented. © 2002 Wiley Periodicals, Inc., Mass Spec Rev 20:347–361, 2001; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mas.10007
Electrophysiological diagnostic criteria of Lambert–Eaton myasthenic syndrome
Authors: Oh Shin J. , Kurokawa Katsumi , Claussen Gwen C. , Ryan Hewitt F.
Published: July 2005

Various parameters of the repetitive nerve stimulation (RNS) test of the abductor digiti quinti muscle were analyzed statistically in 34 patients with Lambert–Eaton myasthenic syndrome (LEMS). The sensitivity and specificity of the increments after exercise and after 50‐HZ stimulation for the diagnosis of LEMS were compared with reference values in 40 normal subjects and data from 538 tests in patients with myasthenia gravis (MG). When we used a 100% increment (the “gold standard”) as the normal limit for the postexercise facilitation (PEF) or the high‐rate stimulation (HRS) test, the diagnosis of LEMS was confirmed in 29 (85%) cases. When a 60% increment was used as the normal limit, the diagnosis of LEMS was made in 97% of cases. In MG, a 60% increment was observed in only 4 of 538 cases by HRS and in none by the exercise test. Thus, the use of a 60% increment showed a sensitivity of 97% for the diagnosis of LEMS and a specificity of 99% in excluding MG. A 60% increment in either the PEF or HRS test for the diagnosis of LEMS is a desirable alternative to the 100% increment previously considered to be the gold standard for this diagnosis. Muscle Nerve, 2005
Noninvasive monitoring of muscle damage during reloading following limb disuse
Authors: Frimel Tiffany N. , Walter Glenn A. , Gibbs John D. , Gaidosh Gabriel S. , Vandenborne Krista
Published: July 2005

Cast immobilization causes skeletal muscle disuse atrophy and an increased susceptibility to muscle damage. The objective of this study was to explore the utility of noninvasive magnetic resonance (MR) imaging to monitor muscle damage in the lower hindlimb muscles of the mouse during reloading following cast immobilization and to compare the findings in different muscles. The hindlimbs of C57BL6 mice were immobilized for 2 weeks in plantarflexion using a bilateral casting model. Following immobilization the mice were allowed to reambulate and muscle damage was monitored at different times. Cage‐restricted reloading following cast immobilization induced a significant shift (P < 0.0001) in the transverse (T2) relaxation characteristics of the postural slow‐twitch soleus muscle, but not in the neighboring gastrocnemius. Soleus T2 values peaked at 2 days of reloading. Muscle‐specific changes in MR T2 relaxation properties correlated with uptake of Evans blue dye, a histological marker of muscle damage. This study demonstrates that T2 MR imaging can be implemented to monitor noninvasively and sequentially muscle‐specific damage during reloading following limb disuse. Muscle Nerve, 2005
Particle‐In‐Cell/Monte‐Carlo Simulation of Plasma and Neutral Gas Flow for the Inner Coating of PET Bottles by Plasma‐Based Ion Implantation. N2 Gas Plasma
Authors: Miyagawa Yoshiko , Tanaka Masaaki , Nakadate Hiroshi , Ikeyama Masami , Miyagawa Soji
Published: July 2005

Summary: Plasma behavior inside of a PET bottle together with the gas flow has been analyzed under plasma‐based ion implantation (PBII) conditions. The software “PEGASUS” with the cylindrical coordinate system was used for the simulation. PEGASUS uses the particle‐in‐cell (PIC) method for the movement of charged particles in the electromagnetic field and the Monte Carlo method for collisions of ions, electrons, and neutrals in the plasma in a low‐pressure gas. The gas flow is analyzed by the Monte Carlo method. It gives spatial distributions of densities, velocities, fluxes, temperatures and pressures of each neutral species. The plasma simulation was coupled with the gas flow simulation, and the plasma behavior in the flowing N2 gas was analyzed. The gas pressure was 10 and 50 Pa; a positive pulse voltage (maximum voltage = 500 V) was applied to the center rod from where the gas flows. Time evolutions of spatial distributions of the potential and the densities of ions, electrons and radicals in the coating system were obtained together with the flux of ions and electrons on the target surface.

Time evolution of spatial distribution of N ion density. Conditions: N2 gas: 10 Pa, Vmax = 500 V, γ = 1.

magnified image

Time evolution of spatial distribution of N ion density. Conditions: N2 gas: 10 Pa, Vmax = 500 V, γ = 1.
Crystal structure and magnetic properties of mixed compounds Nd1–xRxCo3 (R = Gd, Tb)
Authors: Ouyang Z. W. , Rao G. H. , Liu W. F. , Liu G. Y. , Feng X. M. , Liang J. K.
Published: July 2005

The crystal structure and magnetic properties of Nd1–xRxCo3 (R = Gd, Tb) have been investigated by means of X‐ray powder diffraction and magnetic measurements. Spin reorientation and magnetization compensation are observed in both systems. The saturation magnetization MS of Nd1–xTbxCo3 exhibits an anomaly at a critical concentration xc ≈ 0.55, whereas no such an anomaly is observed for Nd1–xGdxCo3. These observations could be understood by considering the difference of the anisotropy between Tb3+ and Gd3+ ions. The type of magnetocrystalline anisotropy of the compounds is derived based on X‐ray diffraction patterns of the field‐aligned samples. For Nd1–xTbxCo3, the anisotropy near xc is weak with an undefined easy magnetization direction. On the Nd‐rich side, the anisotropy exhibits a strong temperature dependence. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Use of the modified Ginzburg–Landau equations in high temperature superconductors
Authors: Shehata L. N. , Taha H. M.
Published: July 2005

The modified Ginzburg–Landau equations are used to study some selected problems for the high temperature superconductors. The derivations of modified Ginzburg–Landau equations are briefly demonstrated by taking into consideration the layered features of the sample according to the relation between the coherence length and the separation distance of the layers. The domain wall energy, the maximum supercurrent and the parallel critical field of high temperature superconducting thin film were evaluated. Comparison with previous works is given. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Low‐energy spectrum of one‐dimensional generalized Wigner lattice
Authors: Slavin V.
Published: July 2005

The low‐energy spectrum of one‐dimensional lattice electron system with long‐range inter‐electron repulsion is studied at arbitrary electron concentration, ρ. It is established that the value of the gap in this spectrum is an oscillating function of inverse electron concentration. This value tends to zero at ρ = 1/q (q = 1, 2 …), reaching the maximum at ρ = 2/(2q + 1). It is shown that the low‐energy spectrum of the system under consideration may be described in terms of one‐dimensional structures which are analogues of domains in one‐dimensional spin systems. The question about these “domains” decay is considered. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
First‐principles calculations of the CaF2 bulk and surface electronic structure
Authors: Shi H. , Eglitis R. I. , Borstel G.
Published: July 2005

We present and discuss the results of calculations of the CaF2 bulk and surface electronic structure. These are based on the ab initio Hartree–Fock (HF) method with electron correlation corrections and on Density Functional Theory (DFT) calculations with different exchange‐correlation functionals, including hybrid exchange techniques. Both approaches use the localised Gaussian‐type basis set. According to our calculations the ab initio HF method considerably overestimates (20.77 eV) the optical band gap, whereas the density functional calculations based on the Kohn–Sham equation with a number of exchange‐correlation functionals, including local density approximation (LDA) (8.72 eV), generalized gradient approximations (GGA) by Perdew and Wang (PW) (8.51 eV), and Perdew, Burke, and Ernzerhof (PBE) (8.45 eV) underestimate it. Our results show that the best agreement with experiment (12.1 eV) can be obtained using a hybrid HF–DFT exchange functional, in which Hartree–Fock exchange is mixed with DFT exchange functionals, using Beckes three parameter method, combined with the non‐local correlation functionals by Perdew and Wang (B3PW) (10.96 eV). We also present calculations of CaF2(111), (110), and (100) surfaces. Our calculated surface energies using the hybrid B3PW method confirm that the CaF2(111) surface is the most stable one, in agreement with the experiment. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characterization of carbofuran photodegradation by‐products by liquid chromatography/hybrid quadrupole time‐of‐flight mass spectrometry
Authors: Detomaso Antonia , Mascolo Giuseppe , Lopez Antonio
Published: July 2005

An Erratum has been published for this article in Rapid Communications in Mass Spectrometry 19(17) 2005, 2480.

The structural elucidation of by‐products arising from carbofuran photodegradation using a high‐pressure UV lamp has been investigated by liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI‐MS/MS) employing a quadrupole time‐of‐flight mass spectrometer. Exact mass measurements of the [M + H]+ ions of the by‐products and of product ions allowed the elemental formulae and related structures of seven photodegradation by‐products (resulting, respectively, from photo‐Fries rearrangement, hydroxylation of the benzene ring, oxidation of the 2,3‐dihydrobenzofuran ring, cleavage of the carbamate group, hydrolysis of the ether group and the newly observed radical coupling and decarboxylation processes) to be determined confidently. Accurate mass measurements of product ions allowed ambiguities to be removed concerning neutral losses having the same nominal mass, namely CO and C2H4, allowing the fragmentation patterns to be rationalized. Copyright © 2005 John Wiley & Sons, Ltd.
Quantitative analysis of the farnesyl transferase inhibitor lonafarnib (Sarasar™, SCH66336) in human plasma using high‐performance liquid chromatography coupled with tandem mass spectrometry
Authors: Appels Natalie M. G. M. , van Maanen Maria J. , Rosing Hilde , Schellens Jan H. M. , Beijnen Jos H.
Published: July 2005

Lonafarnib is a novel anticancer drug that inhibits farnesyl transferase. To assess its pharmacokinetic properties, we developed a sensitive and quantitative assay using liquid chromatography coupled with tandem mass spectrometry for the determination of lonafarnib levels in human plasma. Sample pretreatment consisted of the addition of an isotopically labeled internal standard and protein precipitation with acetonitrile using 100 µL plasma. Chromatographic separation was performed on an Inertsil ODS‐3 analytical column (50 × 2.1 mm i.d., particle size 5 µm) with acetonitrile/water/formic acid (50:50:0.05, v/v/v) as the mobile phase, at a flow rate of 0.2 mL/min. The analytical run time was 8 min. An API365 triple quadrupole mass spectrometer was used for specific and sensitive detection. It was operated in the positive ion mode and multiple reaction monitoring was used for drug quantification. The method was validated using a concentration range of 2.5 to 2500 ng/mL lonafarnib. Validation of the assay was performed according to the most recent FDA guidelines for bioanalytical method validation and all results were within the requirements. The described method was successfully applied to support a clinical phase I trial with lonafarnib. Copyright © 2005 John Wiley & Sons, Ltd.
A reification calculus for model-oriented software specification
Authors: Oliveira J. N.
Published: July 2005

This paper presents a transformational approach to the derivation of implementations from model-oriented specifications of abstract data types.

The purpose of this research is to reduce the number of formal proofs required in model refinement, which hinder software development. It is shown to be applicable to the transformation of models written in META-IV (the specification language of VDM) towards their refinement into, for example, Pascal or relational DBMSs. The approach includes the automatic synthesis of retrieve functions between models, and data-type invariants.

The underlying algebraic semantics is the so-called
final
semantics “à la Wand”: a specification “is” a
model
(heterogeneous algebra) which is the final object (up to isomorphism) in the category of all its implementations.

The transformational calculus approached in this paper follows from exploring the properties of finite, recursively defined sets.

This work extends the well-known strategy of program transformation to model transformation, adding to previous work on a transformational style for operation-decomposition in META-IV. The model-calculus is also useful for improving model-oriented specifications.
Branching versus linear logics yet again
Authors: Carmo José , Sernadas Amílcar
Published: July 2005

A brief overview is given of the temporal logics used in concurrent program verification and in database and systems specification. The properties of the underlying modal frame structures are analysed. The relative advantages of the linear and branching approaches are discussed. The state versus path formulas controversy is revisited. A meta-linear operatorLis proposed and compared with the “in all trajectories” operator considered in the language CTL*. The usefulness of the new operator within the context of a layered methodology for database and information systems specification and verification is illustrated. The operator is seen as a “frame change operator” and other interesting operators of this class are referred. Finitary and infinitary axiomatisations are given for the operatorL. The proof of the completeness of the infinitary axiomatisation is briefly outlined. This proof requires an appropriate extension of the usual Henkin methods.
A fast pattern matching algorithm derived by transformational and assertional reasoning
Authors: Partsch H. A. , Stomp F. A.
Published: July 2005

Highly optimised algorithms are, in general, hard to understand. This is a consequence of the designer's sacrifice of clarity and modularity in favour of efficiency. In this paper we present a formal derivation of a rather ingenious algorithm, viz., the fast pattern matching algorithm of Boyer and Moore. The development illustrates that transformational programming combined with assertional reasoning provides an appropriate approach for developing and understanding highly optimised algorithms.
Chain properties of rule closures
Authors: Hermann Miki
Published: July 2005

This article introduces a generalisation of the crossed rule approach to the detection of Knuth-Bendix completion procedure divergence. It introduces closure chains, which are special rule closures constructed by means of particular substitution operations and operators, as a suitable formalism for progress in this direction. Supporting substitution algebra is developed first, followed by considerations concerning rule closures in general, concluding with an investigation of closure chain properties. Issues concerning the narrowing process are not discussed here.
Integrating predicate transition nets with first order temporal logic in the specification and verification of concurrent systems
Authors: He Xudong , Lee John A. N.
Published: July 2005

This paper presents some results of integrating predicate transition nets with first order temporal logic in the specification and verification of concurrent systems. The intention of this research is to use predicate transition nets as a specification method and to use first order temporal logic as a verification method so that their strengths — the easy comprehension of predicate transition nets and the reasoning power of first order temporal logic can be combined. In this paper, a theoretical relationship between the computation models of these two formalisms is presented; an algorithm for systematically translating a predicate transition net into a corresponding temporal logic system is outlined; and a special temporal refutation proof technique is proposed and illustrated in verifying various concurrent properties of the predicate transition net specification of the five dining philosophers problem.
ZD1839 (Gefitinib, ‘Iressa’), an epidermal growth factor receptor‐tyrosine kinase inhibitor, enhances the anti‐cancer effects of TRAIL in human esophageal squamous cell carcinoma
Authors: Teraishi Fuminori , Kagawa Shunsuke , Watanabe Takanori , Tango Yasuhisa , Kawashima Takeshi , Umeoka Tatsuo , Nisizaki Masahiko , Tanaka Noriaki , Fujiwara Toshiyoshi
Published: July 2005

The EGF (epidermal growth factor) receptor‐tyrosine kinase inhibitor ZD1839 (Gefitinib, ‘Iressa’) blocks the cell signaling pathways involved in cell proliferation, survival, and angiogenesis in various cancer cells. TNF‐related death apoptosis inducing ligand (TRAIL) acts as an anticancer agent. We investigated the antitumor effects of ZD1839 alone or in combination with TRAIL against human esophageal squamous cell cancer (ESCC) lines. Although all ESCC cells expressed EGF receptor at a protein level, the effect of ZD1839 on cell growth did not correlate with the level of EGFR expression and phosphorylation of EGF receptor protein in ESCC lines. ZD1839 caused a dose‐dependent growth arrest at G0–G1 phase associated with increased p27 expression. As TE8 cells are resistant to TRAIL, we tested whether ZD1839 combined with TRAIL induced apoptosis of TE8 cells via the inhibition of EGF receptor signaling by ZD1839. ZD1839 inhibited the phosphorylation of Akt, and enhanced TRAIL‐induced apoptosis via activation of caspase‐3 and caspase‐9, and inactivation of Bcl‐xL. Our results indicated that ZD1839 has anti‐cancer properties against human esophageal cancer cells. ZD1839 also augmented the anti‐cancer activity of TRAIL, even in TRAIL‐resistant tumors. These results suggest that treatment with ZD1839 and TRAIL may have potential in the treatment of ESCC patients.
Specific transport of S‐nitrosocysteine in human red blood cells: Implications for formation of S‐nitrosothiols and transport of NO bioactivity within the vasculature
Authors: Sandmann Jörg , Schwedhelm Kathrin S. , Tsikas Dimitrios
Published: July 2005

The transport of various S‐nitrosothiols, NO and NO donors in human red blood cells (RBC) and the formation of erythrocytic S‐nitrosoglutathione were investigated. Of the NO species tested only S‐nitrosocysteine was found to form S‐nitrosoglutathione in the RBC cytosol. l‐Serine, l‐cysteine and l‐lysine inhibited formation of S‐nitrosoglutathione. Incubation of RBC pre‐incubated with S‐[15N]nitroso‐l‐cysteine with native plasma or platelet‐rich plasma led to formation of S‐[15N]nitrosoalbumin and inhibited platelet aggregation, respectively. The specific transporter system of S‐nitroso‐l‐cysteine in the RBC membrane may have implications for formation of S‐nitrosoalbumin and S‐nitrosohemoglobin and for transport of NO bioactivity within the vasculature.
Regulation of Pin1 peptidyl‐prolyl cis/trans isomerase activity by its WW binding module on a multi‐phosphorylated peptide of Tau protein
Authors: Smet Caroline , Wieruszeski Jean-Michel , Buée Luc , Landrieu Isabelle , Lippens Guy
Published: July 2005

The WW module of the peptidyl‐prolyl cis/trans isomerase Pin1 targets specifically phosphorylated proteins involved in the cell cycle through the recognition of phospho‐Thr(Ser)‐Pro motifs. When the microtubule‐associated Tau protein becomes hyperphosphorylated, it equally becomes a substrate for Pin1, with two recognition sites described around the phosphorylated Thr212 and Thr231. The Pin1 WW domain binds both sites with moderate affinity, but only the Thr212–Pro213 bond is isomerized by the catalytic domain of Pin1. We show here that, in a peptide carrying a single recognition site, the WW module increases significantly the enzymatic isomerase activity of Pin1. However, with addition of a second recognition motif, the affinity of both the WW and catalytic domain for the substrate increases, but the isomerization efficacy decreases. We therefore conclude that the WW domain can act as a negative regulator of enzymatic activity when multiple phosphorylation is present, thereby suggesting a subtle mechanism of its functional regulation.
NONE, ONE OR SEVERAL? PERSPECTIVES ON THE UK’S CONSTITUTION(S)
Authors: Feldman David
Published: July 2005

AN inaugural lecture is the occasion when the University of Cambridge can look its gift horse in the mouth, weighing the new professor in the balance against his or her distinguished predecessors. The Rouse Ball Professorship of English Law has been held in the past by a long series of distinguished scholars, from Sir Percy Winfield to my immediate predecessor, Sir Jack Beatson whom we are delighted to welcome back today. Their work has influenced generations of lawyers. They certainly influenced me. Before I encountered Criminal Law: The General Part, a great little volume by Professor Glanville Williams, Learning the Law, was my “Guide, Philosopher and Friend” (as it still says on the cover of the latest edition, now edited by my colleague Professor Tony Smith) as I approached the study of law. Another Rouse Ball Professor, the late Sir William Wade, had a formative effect on my understanding of land law and administrative law both through his famous books, Megarry and Wade on the Law of Real Property (now edited by a former Fellow of Downing College, Dr. Charles Harpum) and Administrative Law (now in the hands of my colleague Dr. Christopher Forsyth), not to mention the lectures that I attended as an undergraduate in (softly be it said) the University of Oxford.
FINANCIAL SERVICES REGULATION UNDER THE FINANCIAL SERVICES AUTHORITY: A REASSERTION OF THE MARKET FAILURE THESIS?
Authors: McVea Harry
Published: July 2005

DESPITE the fact that the “nature, role and form” of financial market regulation has varied—sometimes significantly—from jurisdiction to jurisdiction, traditionally there has been a remarkable degree of unanimity about the need for comprehensive regulatory controls governing the operations of financial institutions and the financial markets more generally. In essence, this consensus derives from a conception of financial markets as being sufficiently distinct from other kinds of economic activity, such as manufacturing electrical goods, or the marketing of adventure holidays, to require extensive regulation and oversight. From a descriptive point of view, the inspiration for much of this regulation—at least in its statutory form—can very often be traced to various reactions to financial crises. In the US, for example, extensive Federal Securities legislation, which has been in place since the 1930s, was Congress’s response to bank runs and alleged financial abuses in the depression era.
Stimulation of innate immunity in newborn kids againstCryptosporidium parvuminfection-challenge by intranasal/per-oral administration of liposomal formulation of N-L18-norAbu-GMDP adjuvant
Authors: TURÁNEK J. , KAšNÁ A. , KOUDELA B. , LEDVINA M. , MILLER A. D.
Published: July 2005

The effects of a liposomal preparation of lipophilic immunomodulator β-D-GlcNstearoyl-(1-4)-norMurNAc-L-Abu-D-isoGln (N-L18-norAbu-GMDP) were investigated on resistance toCryptosporidium parvuminfection in neonatal kids. The liposomal preparation was administered subcutaneously or intranasally/orally (i.n./p.o.) twice at doses of 100 μg, 200 μg, or 1000 μg per kid pre-infection challenge. The treatment schemes were (i) 72 and 24 h pre-infection challenge, (ii) 24 h pre-infection challenge and 24 h post-infection challenge (oral inoculation with 1×107oocysts ofC. parvumin 5 ml of PBS). Administration of liposomal N-L18-norAbu-GMDP by i.n./p.o. route at the cumulative dose of 2000 μg per kid 72 and 24 h pre-infection challenge, lead to substantially increased clearance of coccidian parasites from various parts of the intestine. On the basis of histological examination, the distribution of cryptosporidia in the intestine and the severity of the infection, treated kids were classified on day 5 as having a strong reduction in infection in comparison to the control group (P<0·05). No cryptosporidia were found on the mucosal surface of treated kids by day 10, while the intestines of the control kids were still infected. All doses and routes of administration were judged effective with respect to suppression of cryptosporidia infections.
An investigation of visuospatial memory impairment in children with attention deficit hyperactivity disorder (ADHD), combined type
Authors: BARNETT R. , MARUFF P. , VANCE A.
Published: July 2005

Background. Memory impairment is not considered a core cognitive feature of attention deficit hyperactivity disorder, combined type (ADHD-CT), although it is associated with impairments in attentional and executive functions. This study investigates visuospatial memory impairment, in particular encoding and retrieval aspects, in children with ADHD-CT who are stimulant-medication naive and medicated with stimulant medication.

Method. A cross-sectional study of visuospatial memory in 6- to 12-year-old children with stimulant-medication-naive ADHD-CT (n=62) and medicated ADHD-CT (n=58) compared to an age- and gender-matched healthy control group (n=39) was completed.

Results. Both medication-naive and medicated ADHD-CT groups demonstrated subtle yet significant impairment in visuospatial memory. The memory impairment was delay-independent, which, along with other factors, suggest dysfunction of the encoding rather than retrieval phase of visuospatial memory.

Conclusions. Careful study of large ADHD-CT samples does detect deficits in a visuospatial memory task, but these reflect attentional deficits rather than being specifically due to dysfunction of the medial temporal lobe explicit memory system. Children with ADHD-CT may benefit from cognitive and behavioural strategies focused on improving encoding of relevant information rather than retrieval strategies.
Presentation and frequency of catatonia in new admissions to two acute psychiatric admission units in India and Wales
Authors: CHALASANI PADMAJA , HEALY DAVID , MORRISS RICHARD
Published: July 2005

Background. There are no modern cross-cultural comparative studies of the frequency and clinical presentation of catatonia in a Western country and India using standardized rating instruments and diagnostic criteria.

Method. A total of 104 consecutively admitted patients in Wales and in India were screened for catatonic features using the same standardized rating instrument by the same psychiatrist to generate DSM-IV and other diagnostic criteria for catatonia, and a profile of signs in catatonia. Inter-rater reliability for the ratings made by the research psychiatrist was established with local psychiatrists at each unit.

Results. The frequency of DSM-IV criteria catatonia was 13·5% in India versus 9·6% in Wales (N.S.). The severity of catatonia did not differ between the two units. However, retarded catatonia was more common in India (12·5%) versus Wales (p<0·05) whereas the frequency of excited catatonia was equally common in both units. Catatonia was found in many different mental disorders not just schizophrenia and affective disorder.

Conclusions. Catatonia is commonly found among psychiatric in-patients with a similar frequency and severity but differing clinical presentations in Wales and India. Some classic signs of catatonia like posturing, catalepsy, staring and stupor were more frequent among psychiatric admissions in India than Wales. The differing clinical presentations may be due to differences in demographic features rather than cultural or aetiological factors.