bluuebunny/crossref_metadata_2025 huggingface dataset:
Mass Spectrometric Studies of Non‐Covalent Compounds: Why Supramolecular Chemistry in the Gas Phase?
Authors: Baytekin Bilge , Baytekin H. Tarik , Schalley Christoph A.
Published: November 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Arylthiopyrrole (AThP) Derivatives as Non‐Nucleoside HIV‐1 Reverse Transcriptase Inhibitors: Synthesis, Structure–Activity Relationships, and Docking Studies (Part 1)
Authors: Di Santo Roberto , Costi Roberta , Artico Marino , Miele Gaetano , Lavecchia Antonio , Novellino Ettore , Bergamini Alberto , Cancio Reynel , Maga Giovanni
Published: November 2006

Novel arylthio isopropyl pyridinylmethylpyrrolemethanol (AThP) derivatives 3–5, which are related to capravirine (S‐1153), were synthesized and tested for their ability to block the replication cycle of HIV‐1 in infected cells. The newly synthesized AThPs are active in the concentration range of 0.008–53 μM. Even if compounds 3–5 are generally less potent than S‐1153, their SI values are in some cases similar to that of the reference drug. In fact, the cytotoxicities of AThPs are generally lower than that of S‐1153. Compound 4 e was the most active derivative of this series in cell‐based assays; its potency is similar to that of S‐1153 (EC50=8 and 3 nM, respectively), as is its selectivity index (SI=6250 and 7000, respectively). AThP derivatives were proven to target HIV‐1 RT. In fact, compounds 3–5 generally inhibited the viral enzyme at concentrations similar to those observed in cell‐based assays. A selected number of AThPs (4 k and 5 a,e) were tested against clinically relevant drug‐resistant forms of recombinant reverse transcriptase (rRT) carrying the K103N and Y181I mutations. Carbamate 5 e showed an approximate 240‐fold decrease in activity against Y181I, but only a 10‐fold loss in potency against the K103N rRT form. Docking calculations were also performed to investigate the binding mode of compounds 2, 4 e, 4 j, 4 k and 5 e into the non‐nucleoside binding site of HIV‐1 RT and to rationalize some structure–activity relationships and resistance data.
Arylthiopyrrole (AThP) Derivatives as Non‐Nucleoside HIV‐1 Reverse Transcriptase Inhibitors: Synthesis, Structure–Activity Relationships, and Docking Studies (Part 2)
Authors: Lavecchia Antonio , Costi Roberta , Artico Marino , Miele Gaetano , Novellino Ettore , Bergamini Alberto , Crespan Emmanuele , Maga Giovanni , Di Santo Roberto
Published: November 2006

Arylthio isopropyl pyridinylmethylpyrrolemethanols (AThPs) have been recently reported as a new class of human immunodeficiency virus type 1 (HIV‐1) reverse transcriptase (RT) inhibitors acting at the non‐nucleoside binding site (NNBS) of this enzyme. Docking experiments of the potent inhibitors 4 k (IC50=0.24  μM, SI=167) and 5 e (IC50=0.11 μM, SI>1667) of wild‐type RT prompted the synthesis and biological evaluation of novel AThP derivatives featuring a number of polar groups in position 3 of the pyrrole ring and larger and more hydrophobic alicyclic substituents in place of the isopropyl group at position 4. Among the compounds synthesized and tested in cell‐based assays against HIV‐1 infected cells, 19 b was the most active, with EC50=0.007 μM, CC50=114.5 μm, and SI=16357. This compound and its precursor 18 b retained interesting activities against clinically relevant drug‐resistant RT forms carrying K103N, Y181I, and L100I mutations. Docking calculations of 10, 14, 18 b, and 19 b were also performed to investigate their binding mode into the RT NNBS and to rationalize both structure–activity relationship and resistance data.
HR‐MAS NMR spectroscopy in the characterization of human tissues: Application to healthy gastric mucosa
Authors: Schenetti Luisa , Mucci Adele , Parenti Francesca , Cagnoli Rita , Righi Valeria , Tosi M. Raffaella , Tugnoli Vitaliano
Published: November 2006

The HR‐MAS is an ideal technique for the investigation of intact tissue specimens (10–50 mg) and permits the obtainment of spectra with a resolution comparable to that observed in solution in a time that does not exceed a half of an hour for a routine analysis. The potentialities of HR‐MAS NMR spectroscopy in the identification of the metabolites characterizing the healthy gastric mucosa are here presented. The direct inspection of the 1D 1H NMR spectra enables only few metabolites to be confidently assigned, and the use of selected 2D experiments strongly amplify the analytical effectiveness of the technique. © 2006 Wiley Periodicals, Inc. Concepts Magn Reson Part A 28A: 430–443, 2006
Stress analyses of laminates under cylindrical bending
Authors: Kant Tarun , Desai Yogesh , Pendhari Sandeep
Published: November 2006

A semi‐analytical approach for evaluation of stresses and displacements in composite and sandwich laminates under cylindrical bending subjected to transverse load has been developed in this paper. Two dimensional (2D) partial differential equations (PDEs) of such a laminate are obtained by imposing plane‐strain conditions of elasticity. The fundamental dependent variables are so selected in this formulation that they satisfy the continuity of displacements and transverse interlaminar stresses at the laminate interface through the thickness. The set of governing PDEs are transformed into a set of coupled first‐order ordinary differential equations (ODEs) in thickness direction by assuming suitable global orthogonal trigonometric functions for the fundamental variables satisfying the boundary conditions. These ODEs are numerically integrated by a specially formulated ODE integrator algorithm involving transformation of a two‐point boundary value problem (BVP) into a set of initial value problems (IVPs). Numerical studies on both composite and sandwich laminates for various aspect ratios are performed and presented. Accuracy of the present approach is demonstrated by comparing the results with the available elasticity solution. It is seen that the present results are in excellent agreement with the elasticity solutions. Some new results for sandwich laminates and for uniform loading condition are presented for future reference. Copyright © 2006 John Wiley & Sons, Ltd.
On closed boundary value problems for equations of mixed elliptic‐hyperbolic type
Authors: Lupo Daniela , Morawetz Cathleen S. , Payne Kevin R.
Published: November 2006

For partial differential equations of mixed elliptic‐hyperbolic type we prove results on existence and existence with uniqueness of weak solutions for closed boundary value problems of Dirichlet and mixed Dirichlet‐conormal types. Such problems are of interest for applications to transonic flow and are overdetermined for solutions with classical regularity. The method employed consists in variants of the a − b − c integral method of Friedrichs in Sobolev spaces with suitable weights. Particular attention is paid to the problem of attaining results with a minimum of restrictions on the boundary geometry and the form of the type change function. In addition, interior regularity results are also given in the important special case of the Tricomi equation. © 2006 Wiley Periodicals, Inc.
Asymptotic behavior of the global attractors to the Boussinesq system for Rayleigh‐Bénard convection at large Prandtl number
Authors: Wang Xiaoming
Published: November 2006

We study asymptotic behavior of the global attractors to the Boussinesq system for Rayleigh‐Bénard convection at large Prandtl number. In particular, we show that the global attractors to the Boussinesq system for Rayleigh‐Bénard convection converge to that of the infinite‐Prandtl‐number model for convection as the Prandtl number approaches infinity. This offers partial justification of the infinite‐Prandtl‐number model for convection as a valid simplified model for convection at large Prandtl number even in the long‐time regime. © 2006 Wiley Periodicals, Inc.
Behavior of Temperature‐Sensitive PNIPAM Confined in Polyelectrolyte Capsules
Authors: Prevot Michelle , Déjugnat Christophe , Möhwald Helmuth , Sukhorukov Gleb B.
Published: November 2006

Layer‐by‐layer assembled polyelectrolyte microcapsules are of great interest because they can possibly be used as microcontainers and they show interesting stimuli‐responsive properties, which have been recently investigated. Here, we exploit capsules which are made temperature‐sensitive by encapsulating poly(N‐isopropylacrylamide) (PNIPAM). PNIPAM has a cloud point in water at about 32 °C, above which it collapses and is insoluble in water. Further this temperature responsiveness can be tuned by addition of various ions at various concentrations. Here, we present the encapsulation of PNIPAM inside polyelectrolyte microcapsules, and describe the dependence of the lower critical solution temperature (LCST) on the nature and the amount of different salts added. With this information, we demonstrate the ability to tune and finely control the collapse of encapsulated PNIPAM. In this light, this system could be used as a microsensor or drug‐ delivery system.
Magnetic Properties of Poly(propylene imine)–Copper Dendromesogenic Complexes: An EPR Study
Authors: Domracheva Natalia , Mirea Anisoara , Schwoerer Markus , Torre‐Lorente Laura , Lattermann Günter
Published: November 2006

Copper(II) complexes formed by coordination of the CuII ion with liquid‐crystalline poly(propylene imine) dendrimer ligand (L) of the first (complex 1) and second (complex 2) generations with various CuII contents (x=Cu/L) have been studied by electron paramagnetic resonance (EPR) spectroscopy. The existence of a redox‐active blue complex 1 (x=1.9) and the copper(II) nitrate electron transfer associated with the valence tautomerism are revealed for the first time in copper‐based dendrimers. It has been shown that the electronic structure of the blue complex 1 (x=1.9) is adequately described as a mixed‐valence dimer containing d 9‐ and diamagnetic d 10‐configurated copper ions, and an antiferromagnetically coupled NO3. radical arising on the nitrate‐bridged counter ligand. The activation energy value found for the electron transfer is about 0.35 meV, which indicates a low‐energy charge dynamic. The ability of the blue and green complexes 1 (x=1.9) dissolved in isotropic solvents to orient themselves in the magnetic field was revealed by EPR spectroscopy. The degree of orientation of the molecular z axis (Sz) of these complexes in the magnetic field differs, depending on the type of copper(II)‐complexing site in the dendrimer ligand, and can reach 0.76, which is close to Sz=1 (completely aligned system). A combination of magnetic and orientational parameters indicates an NO4 environment of the CuII ion in green complex 1 (x=1.9), and confirms the chain structure with intermolecular CuII–NO3–CuII bridges between CuII centres in columns.
Effects of lactate and acetate on the determination of serum ethyl glucuronide by CZE
Authors: Mrázková Michaela , Caslavska Jitka , Thormann Wolfgang , Křivánková Ludmila
Published: November 2006

The analysis of ethyl glucuronide (EtG), a marker of recent alcohol consumption, in serum with an optimized CZE assay is reported. The method uses a 0.1‐mm id fused‐silica capillary of 50 cm effective length that is coated with linear polyacrylamide, a pH 4.4 nicotinic acid/ϵ‐aminocaproic acid (EACA) BGE, reversed polarity and indirect analyte detection. The assay is based on a 1:1 dilution of serum with deionized water and has LODs for EtG, lactate and acetate of 3.8×10−7 M, 2.60×10−6 M and 2.18×10−6 M, respectively. Separation of EtG from endogenous macro‐ and microcomponents (anionic serum components of high and low concentration, respectively) and its quantification are shown to be possible for a wide range of lactate (stacker) and acetate (destacker) concentrations, macrocomponents that have an impact on the CZE behavior of EtG and that change after intake of ethanol. The assay has been successfully applied to the analysis of EtG, lactate and acetate in (i) sera of volunteers that ingested known amounts of alcohol and (ii) samples of patients that were classified (teetotalers and social drinkers vs. alcohol abusers) via analysis of carbohydrate‐deficient transferrin.
On‐line CE‐MS using pressurized liquid junction nanoflow electrospray interface and surface‐coated capillaries
Authors: Fanali Salvatore , D'Orazio Giovanni , Foret Frantisek , Kleparnik Karel , Aturki Zeineb
Published: November 2006

A simple and cost‐effective laboratory‐made liquid junction interface was used for coupling of CE with MS. In this device the capillary column and the spray tip were positioned in the electrode vessel containing appropriate spray liquid. The electrospray potential was applied on the electrode inside the liquid junction. A stable electrospray was produced at nanoliter per minute flow rates generated in the emitter tip without using an external pump. This arrangement provided high durability of the spray tip and independent optimization of the CE separation (use of coated capillaries) and ESI conditions. CE‐MS analysis of mixtures of drugs, peptides, tryptic digests of proteins and biological fluids was optimized with respect to the effects of the distance between the separation capillary and electrospray tip and pressure applied on the liquid junction. The sensitivity of the system, in terms of the LOD (base peak monitoring) was below 10 ng/mL for the β‐blocker drugs and below 200 ng/mL for peptide analysis.
Assessing the performance of intumescent coatings using bench‐scaled cone calorimeter and finite difference simulations
Authors: Bartholmai M. , Schartel B.
Published: November 2006

A method was developed to assess the heat insulation performance of intumescent coatings. The method consists of temperature measurements using the bench‐scaled experimental set‐up of a cone calorimeter and finite difference simulation to calculate the effective thermal conductivity dependent on time/temperature. This simulation procedure was also adapted to the small scale test furnace, in which the standard time–temperature curve is applied to a larger sample and thus which provides results relevant for approval. Investigations on temperature and calculated effective thermal conduction were performed on intumescent coatings in both experimental set‐ups using various coating thicknesses. The results correspond to each other as well as showing the limits of transferability between both fire tests. It is shown that bench‐scaled cone calorimeter tests are a valuable tool for assessing and predicting the performance of intumescent coatings in larger tests relevant for approval. The correlation fails for processes at surface temperatures above 750°C, which are not reached in the cone calorimeter, but are attained in the small scale furnace set‐up. Copyright © 2006 John Wiley & Sons, Ltd.
IFN‐γ‐induced BACE1 expression is mediated by activation of JAK2 and ERK1/2 signaling pathways and direct binding of STAT1 to BACE1 promoter in astrocytes
Authors: Cho Hyun Jin , Kim Su‐Kyoung , Jin Seok Min , Hwang Eun‐Mi , Kim Yong Sik , Huh Kyoon , Mook‐Jung Inhee
Published: November 2006

β‐Site APP cleaving enzyme 1 (BACE1) is an essential enzyme for the production of β amyloid. Since we found that injection of interferon‐γ (IFN‐γ) into young mouse brains increased BACE1 expression in astrocytes, we investigated molecular mechanisms underlying this process by cloning a putative BACE1 promoter. BACE1 promoter activity was differentially regulated by IFN‐γ in a region specific manner and down‐regulated by an inhibitor of Janus kinase 2 (JAK2). A dominant negative mutant of signal transducer and activator of transcription 1 (STAT1) expression suppressed BACE1 promoter activity, and this was rescued by transfecting wild type STAT1. Electrophoretic mobility shift assay and promoter activity assays indicated that STAT1 binds directly to the putative STAT1 binding sequence of BACE1 promoter. Because IFN‐γ treatment induced STAT1 phosphorylation, we examined whether the expression of a suppressor of cytokine signaling (SOCS), negative regulator of JAK2, suppresses BACE1 promoter activity. The results show that SOCS1 or SOCS3 expression suppressed BACE1 promoter by blocking phosphorylation of Tyr701 residue in STAT1. Also, because IFN‐γ treatment specifically potentiated extracellular signal regulated MAP kinase (ERK) 1/2 activation, pretreatment of mitogen‐activated or extracellular signal‐regulated protein kinase (MEK) inhibitor, PD98059, significantly attenuated IFN‐γ‐induced BACE1 promoter activity and protein expression through blocking phosphorylation of Ser727 residue in STAT1, suggesting that ERK1/2 is associated with IFN‐γ‐induced STAT1 signaling cascade. Taken together, our results suggest that IFN‐γ activates JAK2 and ERK1/2 and then phosphorylated STAT1 binds to the putative STAT1 binding sequences in BACE1 promoter region to modulate BACE1 protein expression in astrocytes. © 2006 Wiley‐Liss, Inc.
TNF‐α/IFN‐γ‐induced iNOS expression increased by prostaglandin E2 in rat primary astrocytes via EP2‐evoked cAMP/PKA and intracellular calcium signaling
Authors: Hsiao Han‐Yun , Mak Oi‐Tong , Yang Chung‐Shi , Liu Yu‐Peng , Fang Kuan‐Ming , Tzeng Shun‐Fen
Published: November 2006

Astrocytes, the most abundant glia in the central nervous system (CNS), produce a large amount of prostaglandin E2 (PGE2) in response to proinflammatory mediators after CNS injury. However, it is unclear whether PGE2 has a regulatory role in astrocytic activity under the inflamed condition. In the present work, we showed that PGE2 increased inducible nitric oxide synthase (iNOS) production by tumor necrosis factor‐α and interferon‐γ (T/I) in astrocytes. Pharmacological and RNA interference approaches further indicated the involvement of the receptor EP2 in PGE2‐induced iNOS upregulation in T/I‐treated astrocytes. Quantitative real‐time polymerase chain reaction and gel mobility shift assays also demonstrated that PGE2 increased iNOS transcription through EP2‐induced cAMP/protein kinase A (PKA)‐dependent pathway. Consistently, the effect of EP2 was significantly attenuated by the PKA inhibitor KT‐5720 and partially suppressed by the inhibitor (SB203580) of p38 mitogen‐activated protein kinase (p38MAPK), which serves as one of the downstream components of the PKA‐dependent pathway. Interestingly, EP2‐mediated PKA signaling appeared to increase intracellular Ca2+ release through inositol triphosphate (IP3) receptor activation, which might in turn stimulate protein kinase C (PKC) activation to promote iNOS production in T/I‐primed astrocytes. By analyzing the expression of astrocytic glial fibrillary acidic protein (GFAP), we found that PGE2 alone only triggered the EP2‐induced cAMP/PKA/p38MAPK signaling pathway in astrocytes. Collectively, PGE2 may enhance T/I‐induced astrocytic activation by augmenting iNOS/NO production through EP2‐mediated cross‐talk between cAMP/PKA and IP3/Ca2+ signaling pathways. © 2006 Wiley‐Liss, Inc.
Downregulation of Kir4.1 inward rectifying potassium channel subunits by RNAi impairs potassium transfer and glutamate uptake by cultured cortical astrocytes
Authors: Kucheryavykh Y. V. , Kucheryavykh L. Y. , Nichols C. G. , Maldonado H. M. , Baksi K. , Reichenbach A. , Skatchkov S. N. , Eaton M. J.
Published: November 2006

Glial cell‐mediated potassium and glutamate homeostases play important roles in the regulation of neuronal excitability. Diminished potassium and glutamate buffering capabilities of astrocytes result in hyperexcitability of neurons and abnormal synaptic transmission. The role of the different K+ channels in maintaining the membrane potential and buffering capabilities of cortical astrocytes has not yet been definitively determined due to the lack of specific K+ channel blockers. The purpose of the present study was to assess the role of the inward‐rectifying K+ channel subunit Kir4.1 on potassium fluxes, glutamate uptake and membrane potential in cultured rat cortical astrocytes using RNAi, whole‐cell patch clamp and a colorimetric assay. The membrane potentials of control cortical astrocytes had a bimodal distribution with peaks at −68 and −41 mV. This distribution became unimodal after knockdown of Kir4.1, with the mean membrane potential being shifted in the depolarizing direction (peak at −45 mV). The ability of Kir4.1‐suppressed cells to mediate transmembrane potassium flow, as measured by the current response to voltage ramps or sequential application of different extracellular [K+], was dramatically impaired. In addition, glutamate uptake was inhibited by knock‐down of Kir4.1‐containing channels by RNA interference as well as by blockade of Kir channels with barium (100 μM). Together, these data indicate that Kir4.1 channels are primarily responsible for significant hyperpolarization of cortical astrocytes and are likely to play a major role in potassium buffering. Significant inhibition of glutamate clearance in astrocytes with knock‐down of Kir4.1 highlights the role of membrane hyperpolarization in this process. © 2006 Wiley‐Liss, Inc.
On elliptic and parabolic systems with x‐dependent multivalued graphs
Authors: Gwiazda Piotr , Zatorska‐Goldstein Anna
Published: November 2006

We consider elliptic and parabolic systems with multivalued x‐dependent graphs. The existence of solutions for elliptic equation was established in (Ann. Inst. H. Poincare Anal. Non Linéaire 1990; 7(3):123–160; Boll. Unione Mat. Ital. Sez. B Artic. Ric. Mat. (8) 2004; 7(1):23–59). We extend this result to the elliptic and parabolic systems, in particular to the systems describing a flow of non‐Newtonian incompressible fluids. Contrary to these two papers we follow the spirit of the compactness method of J. L. Lions for variational‐type operators, however, expanded on the framework of measure‐valued solutions. The main concept consists in applying the relation between x‐dependent maximal monotone graphs and 1‐Lipschitz Carathéodory functions to introduce the generalized Young measures. The method was announced in the short note (C. R. Math. Acad. Sci. Paris 2005; 340(7):489–492). Copyright © 2006 John Wiley & Sons, Ltd.
Structural stability for a Brinkman fluid
Authors: Lin Changhao , Payne L. E.
Published: November 2006

In this paper the authors investigate the structural stability of the Brinkman equations which describe the flow of a fluid containing a solute. A model proposed by Straughan and Hutter (Proc. Roy. Soc. London A 1999; 455:767–777) is employed. Copyright © 2006 John Wiley & Sons, Ltd.
Nonlinear SEM numerical analyses of dry dense sand specimens under rapid and dynamic loading
Authors: di Prisco C. , Stupazzini M. , Zambelli C.
Published: November 2006

The paper mainly concerns the mechanical response of 2D dry dense sand specimens under shock loading. The problem is numerically analysed by means of a SEM dynamic code, within which an already conceived non‐local viscoplastic constitutive model characterized by a non‐associated flow rule and by an anisotropic strain hardening has been implemented. In particular the strain localization and time dependency of the material mechanical response are taken into consideration.

Both rapid/static loading and dynamic histories are numerically simulated. In the first case, the time dependency of the material mechanical response can be captured by neglecting inertial effects, while in the second one the two factors are superimposed and the propagation of the stress waves within the specimen is discussed. The interest of these analyses derives from the fact that the diffusion phenomenon takes place within a specimen already localized. Copyright © 2006 John Wiley & Sons, Ltd.
Crack propagation criteria in the framework of X‐FEM‐based structural analyses
Authors: Dumstorff Peter , Meschke Günther
Published: November 2006

The extended finite element method (X‐FEM) has proven to be capable of simulating cracking and crack propagation in quasi‐brittle materials, such as cement paste or concrete, without the need for re‐meshing. In the framework of the X‐FEM cracks are represented as surfaces of discontinuous displacements continuously propagating through finite elements. Since crack path continuity is required in X‐FEM‐based analyses, the reliability of numerical analyses of cracked structures crucially depends on the correct prediction of the crack path and, consequently, on the criterion used for the determination of the crack propagation direction. In this paper four different crack propagation criteria proposed in the literature are investigated including two local and two global criteria. The two local criteria include an averaged stress criterion and the maximum circumferential stress criterion based on the linear elastic fracture mechanics. The two global criteria include a global tracking criterion proposed by Oliver and Huespe (Online Proceedings of the Fifth World Congress on Computational Mechanics, 2002) and an energy based X‐FEM formulation recently proposed in (Computational Plasticity 2005. CIMNE: Barcelona, 2005; 565–568; Comput. Methods Appl. Mech. Eng. 2006, in press). Representative numerical benchmark examples, characterized by mode‐I dominant fracture as well as by mixed‐mode fracture, are used to study the performance and the robustness of the different crack propagation criteria. Copyright © 2006 John Wiley & Sons, Ltd.
Comparison of results of a pilot study of alternating vincristine/doxorubicin/cyclophosphamide and etoposide/ifosfamide with IRS‐IV in intermediate risk rhabdomyosarcoma: A report from the Children's Oncology Group
Authors: Arndt Carola A.S. , Hawkins Douglas S. , Meyer William H. , Sencer Susan F. , Neglia Joseph P. , Anderson James R.
Published: November 2006

Background

Over 50% of patients with rhabdomyosarcoma (RMS) have intermediate risk disease, with a 3‐year failure‐free survival (FFS) of 50%–70% depending on histology. Doxorubicin is active against RMS, but its role in improving outcome remains controversial. Ifosfamide is as active as cyclophosphamide in RMS, with the Fourth Intergroup RMS Study (IRS‐IV) showing equivalent outcomes for patients treated with ifosfamide for the first 28 weeks compared to cyclophosphamide. Treatment with alternating cycles of non‐cross‐resistant chemotherapy has been used in a number of diseases with good results.

Procedure

The results of a pilot study utilizing alternating courses of vincristine, doxorubicin, cyclophosphamide, and etoposide/ifosfamide (VDC/IE) were compared for outcome and patient characteristics to a group of similar matched patients treated on IRS‐IV.

Results

The 5‐year FFS for patients with parameningeal (PM) primaries on IRS‐IV and the VDC/IE study were 72% and 82%, respectively (P = 0.26); for patients with non‐PM primaries, the estimated risk of failure for VDC/IE study versus IRS‐IV was 0.54.

Combining all disease sites and performing analysis for relative risk of failure for 46 VDC/IE patients and 342 IRS‐IV patients, the relative risk of failure for the VDC/IE study compared to the IRS‐IV study is 0.5 (P = 0.06).

Conclusions

VDC/IE is as effective therapy for intermediate risk RMS as IRS‐IV therapy. It is being explored along with irinotecan in relapsed patients and newly diagnosed high‐risk patients. Pediatr Blood Cancer 2008;50:33–36. © 2006 Wiley‐Liss, Inc.
Synthesis of copolymers containing a spiro orthocarbonate moiety and evaluation of the volume change during their cationic crosslinking
Authors: Kume Makoto , Maki Yuya , Ochiai Bungo , Endo Takeshi
Published: November 2006

Spiro orthocarbonate (SOC) monomers having either an exomethylene group {3,3‐dimethyl‐9‐methylene‐1,5,7,11‐tetraoxaspiro[5.5]undecane (ExoSOC)} or an allyl group {9‐allyl‐3,3‐dimethyl‐1,5,7,11‐tetraoxaspiro[5.5]undecane (AllylSOC)} were radically copolymerized with vinyl monomers at several feed ratios to obtain the corresponding copolymers having SOC moieties in the side chain. The obtained copolymers were crosslinked via the double ring‐opening polymerization of the SOC moieties by a treatment with boron trifluoride etherate. The volume changes during the crosslinking of the copolymers were evaluated by density measurements with a gas pycnometer. As the SOC moiety composition increased, the volume shrinkage during the crosslinking was suppressed, and that finally changed into volume expansion. The volume changes during the crosslinking of the copolymers from AllylSOC were slightly larger than those of the copolymers from ExoSOC. The higher volume expansions in the crosslinking of AllylSOC‐based copolymers were ascribable to the lower steric hindrance around the SOC moieties. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 7040–7053, 2006
Ultrathin gradient films using thiol‐ene polymerizations
Authors: Khire Vaibhav S. , Benoit Danielle S. W. , Anseth Kristi S. , Bowman Christopher N.
Published: November 2006

The application of surface‐attached, thiol‐ene polymer films for controlling material properties in a gradient fashion across a surface was investigated. Thiol‐ene films were attached to the surface by first depositing a thiol‐terminated self‐assembled monolayer and performing a thiol‐ene photopolymerization reaction on the surface. Property gradients were created either by creating and modifying a gradient in the surface thiol density in the SAM or by changing the polymerization conditions or both. Film thickness was modified across the substrate by changing either the density of the anchoring thiol functional groups or by changing the reaction conditions such as exposure time. Thicker films (1–11 nm) were obtained by polymerizing acrylate polymer brushes from the surface with varying exposure time (0–60 s). The two factors, that is, the surface thiol density and the exposure time, were combined in orthogonal directions to obtain thiol‐ene films with a two‐dimensional thickness gradient with the maximum thickness being 4 nm. Finally, a thiol‐acrylate Michael type addition reaction was used to modify the surface thiol density gradient with the cell‐adhesive ligand, Arg‐Gly‐Asp‐Ser (RGDS), which subsequently yielded a gradient in osteoblast density on the surface. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 7027–7039, 2006
‘How I was then and how I am now’: current and retrospective self‐reports of anxiety and depression in Australian women with breast cancer
Authors: Sharpley Christopher F. , Christie David R. H.
Published: November 2006

In an attempt to overcome the potential invalidity of response shift present in pre‐test versus post‐test designs, 197 breast cancer patients completed self‐reports about their current anxiety and depression states about 2 years after diagnosis, and also for how they felt at the time of their diagnosis. Current and previous states of anxiety and depression, item analyses and factor analyses of these results, plus MANOVA across all items to test for changes over time (termed ‘actual change’ in the literature) were conducted. In addition, the combined anxiety and depression scores were analysed as a single unit to determine overlap of symptomatology and suggest possible treatments. As well as showing decreases in the proportion of participants who were experiencing clinically significant anxiety and depression from the time of diagnosis to the time of the survey, results indicated changes in the underlying anxiety symptomatology experienced by participants, moving from somatic complaints of fatigue to feelings of loss of control and inability to cope. The predominant symptomatology of depression remained consistently related to an inability to cope or make decisions, feelings of helplessness and loss. Suggestions for helping clinicians to deal with patients' symptomatology are discussed. Copyright © 2006 John Wiley & Sons, Ltd.
Spin effects in quantum dots
Authors: Könemann J. , Winkler R. , Maude D. K. , Haug R. J.
Published: November 2006

Spin‐resolved single‐electron tunneling in GaAs/AlGaAs double‐barrier resonant tunneling structures is used to investigate the spin‐splitting of fully quantized electronic states. With the use of magneto‐tunneling spectroscopy we evaluated the Landé g ‐factor of GaAs quantum dots of different confinement strengths. We observe with increasing confinement a shift of the Landé‐factor from the bulk GaAs‐value towards positive values. Our results are compared to a multiband‐k·p‐calculation. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Inelastic light scattering by low‐lying excitations of electrons in low‐dimensional semiconductors
Authors: Pellegrini V. , Pinczuk A.
Published: November 2006

The low‐dimensional electron systems that reside in artificial semiconductor heterostructures of great perfection are a contemporary materials base for explorations of collective phenomena. Studies of low‐lying elementary excitations by inelastic light scattering offer insights on properties such energetics, interactions and spin magnetization. We review here recent light scattering results obtained from two‐dimensional (2D) quantum fluids in semiconductor heterostructures under extreme conditions of low temperature and large magnetic field, where the quantum Hall phases are archetypes of novel behaviors. We also consider recent light scattering experiments that have probed the excitation spectra of few‐electron states in semiconductor quantum dots. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Evaluating the impact of cannibalization on fleet performance
Authors: Salman Sinan , Cassady C. Richard , Pohl Edward A. , Ormon Stephen W.
Published: November 2006

Organizations that utilize fleets of expensive repairable equipment are faced with numerous challenges related to the specification of maintenance policies and the allocation of maintenance resources. The associated maintenance decisions can have a drastic impact on fleet performance. Due to the significant acquisition costs associated with the components that comprise the units of equipment in the fleet, cannibalization is often used in the absence of available spare parts to enable fleet maintenance managers to satisfy fleet performance constraints such as readiness requirements. This research is focused on the development and analysis of a closed‐network, discrete‐event simulation model that is used to assess the impacts of cannibalization, small spare parts inventories and maintenance‐induced damage on a fleet of systems. Using numerical examples, we demonstrate the comparison between cannibalization and the investment in limited spare parts inventories. We evaluate fleet performance using average readiness and total maintenance cost. Specifically, we demonstrate that investments in spare parts inventories can reduce the need for and value of cannibalization. However, our results also support the use of cannibalization as a low‐cost alternative to investing in expensive spare parts. We also explore the impact of damage induced by maintenance on fleet performance. Specifically, we demonstrate that maintenance‐induced damage can reduce the benefit of cannibalization while drastically increasing maintenance expenditures. Copyright © 2006 John Wiley & Sons, Ltd.
Generalized confidence intervals for process capability indices
Authors: Mathew Thomas , Sebastian G. , Kurian K. M.
Published: November 2006

The concept of generalized confidence intervals is used to derive lower confidence limits for some of the commonly used process capability indices. For the cases where approximate lower confidence limits are already available, numerical comparisons are made among the available approximations and the generalized lower confidence limit. The numerical results indicate that the generalized confidence interval does provide coverage probabilities very close to the nominal confidence level. Two examples are given to illustrate the results. Copyright © 2006 John Wiley & Sons, Ltd.
Multivariate statistical process control charts: an overview
Authors: Bersimis S. , Psarakis S. , Panaretos J.
Published: November 2006

In this paper we discuss the basic procedures for the implementation of multivariate statistical process control via control charting. Furthermore, we review multivariate extensions for all kinds of univariate control charts, such as multivariate Shewhart‐type control charts, multivariate CUSUM control charts and multivariate EWMA control charts. In addition, we review unique procedures for the construction of multivariate control charts, based on multivariate statistical techniques such as principal components analysis (PCA) and partial least squares (PLS). Finally, we describe the most significant methods for the interpretation of an out‐of‐control signal. Copyright © 2006 John Wiley & Sons, Ltd.
A partition experimental design for a sequential process with a large number of variables
Authors: Perry Leonard A. , Montgomery Douglas C. , Fowler John W.
Published: November 2006

Statistically designed experiments provide a systematic approach to study and analyze the effects of multiple factors on process performance. In order to improve the performance across an organization, one must investigate multiple processes from supplier to customer. Partition experimental designs provide a design to model several sequential processes simultaneously. The partition design provides the investigator with an efficient design where potential cost and time constraints exist. That is, partition designs are applicable when runs are costly and a large number of variables exist in the serial process. In this paper, we present the application of partition designs using 10 factors in a simulated case study. The design and analysis procedures are discussed, as well as the benefits. Copyright © 2006 John Wiley & Sons, Ltd.
A statistical monitoring approach for automotive on‐board diagnostic systems
Authors: Barone Stefano , D'Ambrosio Paolo , Erto Pasquale
Published: November 2006

The current generation of vehicle models are increasingly being equipped with on‐board diagnostic (OBD) systems aimed at assessing the ‘state of health’ of important anti‐pollution subsystems and components. In order to promptly diagnose and fix quality and reliability problems that may potentially affect such complex diagnostic systems, even during advanced development prior to mass production, some vehicle prototypes undergo a testing phase under realistic conditions of use (a mileage accumulation campaign). The aim of this work is to set up a statistical tool for improving the reliability of the OBD system by monitoring its operation during the mileage accumulation campaign of a new vehicle model. A dedicated software program was developed by the authors to filter the large experimental database recorded during the mileage accumulation campaign and to extract the time series of the diagnostic indices to be analysed. A model‐based monitoring approach, using continuous time autoregressive (CAR) models for the time‐series structure and traditional control charts for the estimated residuals, is adopted. A Kalman recursion procedure for the estimation of the unknown CAR model parameters is described. An application of the proposed approach is presented for a diagnostic index related to the state of health of the oxygen sensor. Copyright © 2006 John Wiley & Sons, Ltd.
High breakdown estimation methods for Phase I multivariate control charts
Authors: Jensen Willis A. , Birch Jeffrey B. , Woodall William H.
Published: November 2006

A goal of Phase I analysis of multivariate data is to identify multivariate outliers and step changes so that the Phase II estimated control limits are sufficiently accurate. High breakdown estimation methods based on the minimum volume ellipsoid (MVE) or the minimum covariance determinant (MCD) are well suited for detecting multivariate outliers in data. As a result of the inherent difficulties in their computation, many algorithms have been proposed to detect multivariate outliers. Due to their availability in standard software packages, we consider the subsampling algorithm to obtain the MVE estimators and the FAST‐MCD algorithm to obtain the MCD estimators. Previous studies have not clearly determined which of these two available estimation methods is best for control chart applications. The comprehensive simulation study presented in this paper gives guidance for the correct use of each estimator. Control limits are provided. High breakdown estimation methods based on the MCD and MVE approaches can be applied to a wide variety of multivariate quality control data. Copyright © 2006 John Wiley & Sons, Ltd.
Analysis of split‐plot designs: an overview and comparison of methods
Authors: Næs T. , Aastveit A. H. , Sahni N. S.
Published: November 2006

Split‐plot designs are frequently needed in practice because of practical limitations and issues related to cost. This imposes extra challenges on the experimenter, both when designing the experiment and when analysing the data, in particular for non‐replicated cases. This paper is an overview and discussion of some of the most important methods for analysing split‐plot data. The focus is on estimation, testing and model validation. Two examples from an industrial context are given to illustrate the most important techniques. Copyright © 2006 John Wiley & Sons, Ltd.
An adaptive chart for monitoring the process mean and variance
Authors: Costa Antonio F. B. , De Magalhães Maysa S.
Published: November 2006

Traditionally, an $\bar{X}$ chart is used to control the process mean and an R chart is used to control the process variance. However, these charts are not sensitive to small changes in the process parameters. The adaptive $\bar{X}$ and R charts might be considered if the aim is to detect small disturbances. Due to the statistical character of the joint $\bar{X}$ and R charts with fixed or adaptive parameters, they are not reliable in identifying the nature of the disturbance, whether it is one that shifts the process mean, increases the process variance, or leads to a combination of both effects. In practice, the speed with which the control charts detect process changes may be more important than their ability in identifying the nature of the change. Under these circumstances, it seems to be advantageous to consider a single chart, based on only one statistic, to simultaneously monitor the process mean and variance. In this paper, we propose the adaptive non‐central chi‐square statistic chart. This new chart is more effective than the adaptive $\bar{X}$ and R charts in detecting disturbances that shift the process mean, increase the process variance, or lead to a combination of both effects. Copyright © 2006 John Wiley & Sons, Ltd.
Direct structural assignment of neutral and sialylated N‐glycans of glycopeptides using collision‐induced dissociation MSn spectral matching
Authors: Ito Hiroki , Takegawa Yasuhiro , Deguchi Kisaburo , Nagai Shinji , Nakagawa Hiroaki , Shinohara Yasuro , Nishimura Shin‐Ichiro
Published: November 2006

Mass spectrometric analyses of various N‐glycans binding to proteins and peptides are highly desirable for elucidating their biological roles. An approach based on collision‐induced dissociation (CID) MSn spectra acquired by electrospray ionization linear ion trap time‐of‐flight mass spectrometry (ESI‐LIT‐TOFMS) in the positive‐ and negative‐ion modes has been proposed as a direct method of assigning N‐glycans without releasing them from N‐glycopeptides. In the positive‐ion mode of this approach, the MS2 spectrum of N‐glycopeptide was acquired so that a glycoside‐bond cleavage occurs in the chitobiose residue (i.e., GlcNAcβ1‐4GlcNAc, GlcNAc: N‐acetylglucosamine) attached to asparagine (N), and two charges on the [M+H+Na]2+ precursor ion are shared with both of the resulting fragments. These fragments are sodiated Bn‐type fragment ions of oligosaccharide (N‐glycan) and a protonated peptide ion retaining one GlcNAc residue on the asparagine (N) residue. The structure of N‐glycan was assigned by comparing MS3 spectra derived from both the sodiated Bn‐type fragment ions of N‐glycopeptide and the PA (2‐aminopyridine) N‐glycan standard (i.e., MSn spectral matching). In a similar manner, the structural assignment of sialylated N‐glycan was performed by employing the negative‐ion CID MSn spectra of deprotonated Bn‐type fragment ions of N‐glycopeptide and the PA N‐glycan standard. The efficacy of this approach was tested with chicken egg yolk glycopeptides with a neutral and a sialylated N‐glycan, and human serum IgG glycopeptides with neutral N‐glycan isomers. These results suggest that the approach based on MSn spectral matching is useful for the direct and simple structural assignment of neutral and sialylated N‐glycans of glycopeptides. Copyright © 2006 John Wiley & Sons, Ltd.
Computer‐assisted interpretation of atmospheric pressure chemical ionization mass spectra of triacylglycerols
Authors: Cvačka Josef , Krafková Edita , Jiroš Pavel , Valterová Irena
Published: November 2006

Current lipidomics approaches require simple and rapid algorithms enabling the interpretation of mass spectra of lipids. Most lipids are complex mixtures of related components in which the composition of the aliphatic fatty acid chains varies from one molecule to the next. Triacylglycerols (TAGs) are an example of such a lipid class. Fatty acid chains are the only parts of the molecule to change from one species to another. Fatty acids, and consequently also TAGs, can be characterized by two parameters; the number of carbon atoms and the number of double bonds. All calculations reflecting relations among ions in the spectra can be easily made using these parameters. An algorithm for the automated interpretation of TAGs from atmospheric pressure chemical ionization mass spectra (TriglyAPCI) is presented in this paper. The algorithm first identifies diacylglycerol fragments and molecular adducts. In the next step, relations among the ions are searched and possible TAG structures are suggested. Individual features of the algorithm are described in detail and the software performance is demonstrated for the liquid chromatography/mass spectrometric (LC/MS) analysis of TAGs isolated from the termite Prorhinotermes canalifrons. Copyright © 2006 John Wiley & Sons, Ltd.
Assessment of mercury concentrations in small mammals collected near Las Vegas, Nevada, USA
Authors: Gerstenberger S. L. , Cross C. L. , Divine D. D. , Gulmatico M. L. , Rothweiler A. M.
Published: November 2006

Mercury concentrations in liver and hair tissue were determined for five species of small mammals captured near Las Vegas, Nevada, USA. These data were then used to evaluate the suitability of using hair as a noninvasive technique for determining body burdens of mercury. A total of 104 small mammals were captured and analyzed; four main species were examined and included: Dipodomys merriami, Chaetodipus penicillatus, Peromyscus eremicus, and Neotoma lepida. Mean mercury concentrations were highest in N. lepida, followed by D. merriami, C. penicillatus, and P. eremicus respectively. Positive associations were found between hair and liver taken from D. merriami (r = 0.647) and C. penicillatus (r = 0.533) indicating that hair may be a suitable indicator of body burdens in these two species. © 2006 Wiley Periodicals, Inc. Environ Toxicol 21: 583–589, 2006.