bluuebunny/crossref_metadata_2025 huggingface dataset:
Adenovirus‐mediated expression of a soluble fibroblast growth factor receptor inhibits in vitro growth of prostate DU145 cells
Authors: Gowardhan Bharat , West Alaiyi F. , Robson Craig N. , Leung Hing Y.
Published: March 2004

Background

Fibroblast growth factor (FGF) family plays a key role in prostate cancer. The soluble FGF receptor (sFGFR) has been studied with regards to inhibiting cancer growth and was shown to have a dominant negative effect on cellular signaling and function. Using replication deficient adenovirus‐mediated gene transfer, we tested if sFGFR expression may have a suppressive effect on in vitro growth of prostate cancer cells.

Methods

Western analysis was used to verify expression of sFGFR1 and to examine the effect of sFGFR1 on MAP kinase phosphorylation. The effect on proliferation and invasiveness of DU145 cells was examined using the WST‐1 and Matrigel Invasion assay, respectively.

Results

Activation of MAP kinase (pERK1 and 2) by exogenous FGF1, 2, and 7 was suppressed to baseline levels by sFGFR, which was not seen with EGF. Proliferation and invasion of DU145 cells were significantly suppressed by sFGFR.

Conclusions

A replication deficient adenoviral vector system reproducibly expresses sFGFR in prostate cells. Suppression of in vitro growth in DU145 cells by sFGFR provides the basis of a novel therapeutic approach. © 2004 Wiley‐Liss, Inc.
Transgenic mouse with human mutant p53 expression in the prostate epithelium
Authors: Elgavish Ada , Wood Philip A. , Pinkert Carl A. , Eltoum Isam‐Eldin , Cartee Todd , Wilbanks John , Mentor‐Marcel Roycelynn , Tian Liqun , Scroggins Samuel E.
Published: March 2004

Background

Apoptosis is disrupted in prostate tumor cells, conferring a survival advantage. p53 is a nuclear protein believed to regulate cancer progression, in part by inducing apoptosis. To test this possibility in future studies, the objective of the present study was to generate a transgenic mouse model expressing mutant p53 in the prostate (PR).

Methods

Transgene incorporation was tested using Southern analysis. Expression of mutant p53 protein was examined using immunofluorescence microscopy. Apoptosis in the PR was evaluated using the Tunnel method.

Results

A construct, consisting of the rat probasin promoter and a mutant human p53 fragment, was prepared and used to generate transgenic mice. rPB‐mutant p53 transgene incorporation, as well as nuclear accumulation of mutant human p53 protein, was demonstrated. Prostatic intraepithelial neoplasia (PIN) III and IV were found in PR of 52‐week old transgenic mice, whereas no pathological changes were found in the other organs examined. PR ability to undergo apoptosis following castration was reduced in rPB‐mutant p53 mice as compared to non transgenic littermates.

Conclusions

Transgenic rPB‐mutant p53 mice accumulate mutant p53 protein in PR, resulting in neoplastic lesions and reduced apoptotic potential in the PR. Breeding rPB‐mutant p53 mice with mice expressing an oncogene in their PR will be useful in examining interactions of multiple genes that result in progression of slow growing prostate tumors expressing oncogenes alone to metastatic cancer. © 2004 Wiley‐Liss, Inc.
RNA interference targeting Stat3 inhibits growth and induces apoptosis of human prostate cancer cells
Authors: Ok Lee Soo , Lou Wei , Qureshi Khusroo M. , Mehraein‐Ghomi Farideh , Trump Donald L. , Gao Allen C.
Published: March 2004

Stat3, a member of the signal transduction and activation of transcription (STAT) family, is a key signal transduction protein that mediates signaling by cytokines, peptide growth factors, and oncoproteins and is constitutively activated in numerous cancers including prostate. Previous studies demonstrated that constitutively activated Stat3 plays an important role in the development and progression of prostate cancer by promoting cell proliferation and protecting against apoptosis. The present study was designed to investigate the potential use of RNA interference to block Stat3 expression and activation and the effect on the growth of human prostate cancer cells. We identified a small interfering RNA (siRNA) specific for Stat3 and demonstrate that blockade of Stat3 activation by the Stat3 siRNA suppresses the growth of human prostate cancer cells and Stat3‐mediated gene expression and induces apoptotic cell death. The Stat3 siRNA does not inhibit the proliferation nor induces apoptosis of Stat3‐inactive human prostate cancer cells. In addition, the Stat3 siRNA inhibits the levels of androgen‐regulated prostate specific antigen (PSA) expression in prostate cancer cells. These results demonstrate that targeting Stat3 signaling using siRNA technique may serve as a novel therapeutic strategy for treatment of prostate cancer expressing constitutively activated Stat3. © 2004 Wiley‐Liss, Inc.
Anti‐prostate specific membrane antigen designer T cells for prostate cancer therapy
Authors: Ma Qiangzhong , Safar Mazin , Holmes Eric , Wang Yawen , Boynton Alton L. , Junghans Richard P.
Published: March 2004

Background

Designer T cells are T lymphocytes engineered toward specific antibody‐type membrane antigens through chimeric immunoglobulin‐T‐cell receptor (IgTCR) genes that have been used for adoptive cellular immunotherapy. We have extended this approach to prostate specific membrane antigen (PSMA) as a means to attack prostate cancer.

Methods

A chimeric anti‐PSMA IgTCR gene was constructed based on an anti‐PSMA monoclonal antibody, 3D8. Both T‐cell lines and primary cultured human T lymphocytes were transduced with the chimeric anti‐PSMA IgTCR construct and were analyzed for IgTCR expression, specific activation by PSMA, cytotoxicity against PSMA‐expressing tumor cells in vitro, and retardation of tumor growth in an animal model.

Results

The IgTCR was incorporated into the TCR–CD3 complex and formed a functional chimeric complex. The IgTCR‐modified T cells were specifically activated through the chimeric receptor with PSMA as measured by IL‐2 production and increased CD25 expression and specifically lysed the PSMA‐expressing prostate cancer cells in vitro as well as retarded tumor growth in an animal model.

Conclusions

The anti‐PSMA designer T cells exhibit an antibody‐type specificity that can recognize PSMA expressing tumor cells in a MHC‐independent fashion, resulting in T‐cell activation, target cell lysis in vitro and inhibition of tumor growth in vivo. © 2004 Wiley‐Liss, Inc.
Anti‐tumor effects and lack of side effects in mice of an immunotoxin directed against human and mouse prostate‐specific membrane antigen
Authors: Huang Xianming , Bennett Mary , Thorpe Philip E.
Published: March 2004

Background

Prostate‐specific membrane antigen (PSMA) is a transmembrane protein that is largely restricted to prostatic epithelial cells in humans and is strongly upregulated on prostatic carcinoma cells. It is also expressed on the endothelium of tumor vasculature in humans, but not on the vasculature of normal tissues. Expression of low levels of PSMA has also been found on non‐vascular cells in several normal tissues, most prominently on the brain and kidney in humans. PSMA is an excellent candidate for targeting prostate cancer or targeting tumor vasculature of various solid tumors. The high potential clinical benefit of these agents has prompted the search for an animal model in which to assess the efficacy and safety of anti‐PSMA monoclonal antibody (mAb)‐based therapies.

Methods

A rat monoclonal antibody, E6 that recognizes both mouse and human PSMA was generated using conventional hybridoma techniques. The antibody was characterized by enzyme‐linked immunosorbent assay (ELISA), Western blot, and immunohistochemistry. An immunotoxin composed of E6, antibody and deglycosylated ricin A‐chain (dgA) was prepared chemically. The anti‐tumor effects of the immunotoxin were determined in vitro and in mice bearing subcutaneous LnCaP human prostate tumors, which express PSMA on the tumor cell surface.

Results

E6 recognizes the extracellular domain of both human and mouse PSMA in ELISA, immunoblot and by immunohistochemistry. E6 strongly stained the vascular endothelium of tumors from humans but not from mice. E6 stained proximal tubules in mouse and human kidneys, and neurons in the mouse and human hippocampus but, unlike the human, did not detectably stain epithelial cells in mouse prostate or small intestine. An E6‐dgA immunoconjugate strongly inhibited the growth of LnCaP tumor xenografts without causing apparent toxicity to the mice. Histological observation indicated that the anti‐tumor effects were mediated through direct cytotoxic effects on the tumor cells.

Conclusions

We have generated and characterized a rat mAb (E6) that reacts specifically with both human and mouse PSMA and have demonstrated that an immunotoxin constructed from E6 is safe and effective against human prostatic carcinoma cells growing subcutaneously in nude mice. © 2004 Wiley‐Liss, Inc.
Identification of polycomb group protein enhancer of zeste homolog 2 (EZH2)‐derived peptides immunogenic in HLA‐A24+ prostate cancer patients
Authors: Ogata Rika , Matsueda Satoko , Yao Akihisa , Noguchi Masanori , Itoh Kyogo , Harada Mamoru
Published: March 2004

Background

Antigens overexpressed in metastatic prostate cancer are appropriate targets in anti‐cancer immunotherapy, and one candidate is the polycomb group protein enhancer of zeste homolog 2 (EZH2).

Methods

Eleven EZH2‐derived peptides were prepared based on the HLA‐A24 binding motif. These peptide candidates were screened first by their ability to be recognized by immunoglobulin G (IgG), and then by their ability to induce peptide‐specific cytotoxic T lymphocytes (CTLs).

Results

IgGs reactive to three EZH2 peptides (EZH2‐243 to ‐252, EZH2‐291 to ‐299, and EZH2‐735 to ‐;742) were detected in the plasma of almost half of prostate cancer patients. Among them, the EZH2‐291 to ‐299 and EZH2‐735 to ‐742 peptides effectively induced HLA‐A24‐restricted and prostate cancer‐reactive CTLs from prostate cancer patients. The cytotoxicity was mainly dependent on EZH2 peptide‐specific and CD8+ T cells.

Conclusions

These EZH2‐291 to ‐299 and EZH2‐735 to ‐742 peptides could be promising candidates for peptide‐based immunotherapy for HLA‐A24+ prostate cancer patients with metastases. © 2004 Wiley‐Liss, Inc.
PC‐3 cells with enhanced androgen receptor signaling: A model for clonal selection in prostate cancer
Authors: Buchanan Grant , Craft Paul S. , Yang Miao , Cheong Albert , Prescott Jennifer , Jia Li , Coetzee Gerhard A. , Tilley Wayne D.
Published: March 2004

Background

Two sublines of the human prostate cancer cell line, PC‐3, which is widely used as a model of prostate cancer progression, have been reported: PC‐3AR− that do not express androgen receptor (AR), and PC‐3AR+ that have measurable AR RNA but little protein.

Methods

We assayed the geneotype, karyotype, AR expression, and physical characteristics of the two PC‐3 sublines, and compared their ability to elicit a transactivation response from ectopic AR in the presence and absence of specific AR coregulators.

Results

PC‐3AR− and PC‐3AR+ cells are genotypically and karyotypically similar, but exhibit salient differences in their morphology, growth rate, and expression of AR RNA. Whereas endogenous AR expression in PC‐3AR+ cells does not result in sufficient protein to confer androgen responsiveness in culture, ectopic AR consistently elicited a much greater transactivation response in PC‐3AR+ than in PC‐3AR− cells, without altered sensitivity to activation by native ligand or AR coregulators including GRIP1, BRCA1, and Zac1. Moreover, phenotypic differences of AR variants implicated in prostate cancer susceptibility and progression were only observed in PC‐3AR+ cells. Higher levels of known AR coregulator proteins detected in PC‐3AR+ compared with PC‐3AR− cells likely contribute to these differences.

Conclusions

These studies provide new evidence that the androgen‐signaling axis can be sensitized in prostate cancer cells, and have important implications for the analysis and interpretation of AR structure and function in in vitro cell systems. © 2004 Wiley‐Liss, Inc.
Retinoic acid slows progression and promotes apoptosis of spontaneous prostate cancer
Authors: Huss Wendy J. , Lai Lihua , Barrios Roberto J. , Hirschi Karen K. , Greenberg Norman M.
Published: March 2004

BACKGROUND

All‐trans retinoic acid (ATRA) promotes terminal differentiation in epithelial cells and anti‐angiogenesis and thus, may have beneficial effects in an intervention therapy for prostate cancer.

METHODS

We used the autochthonous spontaneous transgenic adenocarcinoma of the mouse prostate (TRAMP) model system to test the ability of ATRA to prevent initiation and progression of prostate cancer in a pre‐clinical setting.

RESULTS

Initial studies demonstrated that exposure of TRAMP‐derived C2N prostate tumor cells to ATRA in vitro decreased total viable cell numbers with a concomitant decrease in the fraction of cells in S phase. When TRAMP mice were treated in vivo with ATRA for either 6 or 8 weeks at low, medium, or high dose, mice on average presented with lower grade and more differentiated tumors. However, ATRA therapy conferred no significant protection on incidence of tumors or frequency of metastasis at any dose. Nevertheless, we were able to observe a significant decrease in the expression of synaptophysin, a marker of neuroendocrine differentiation, in tumors of mice receiving the highest dose of ATRA. As well, expression of the cell cycle inhibitor p21 was found to be elevated only in well‐differentiated tumors of mice, treated with ATRA while expression of p27, was found to be elevated only in the poorly differentiated tumors.

CONCLUSIONS

Collectively, our in vitro and in vivo data demonstrates that ATRA was able to slow prostate tumor cell proliferation, induce apoptosis, and block the emergence of the neuroendocrine phenotype. Furthermore, our study suggests the differential regulation of p21 and p27 as a molecular mechanism whereby ATRA intervention therapy can inhibit the natural history of spontaneous prostate cancer. © 2004 Wiley‐Liss, Inc.
Evaluation of local structure alphabets based on residue burial
Authors: Karchin Rachel , Cline Melissa , Karplus Kevin
Published: March 2004

Residue burial, which describes a protein residue's exposure to solvent and neighboring atoms, is key to protein structure prediction, modeling, and analysis. We assessed 21 alphabets representing residue burial, according to their predictability from amino acid sequence, conservation in structural alignments, and utility in one fold‐recognition scenario. This follows upon our previous work in assessing nine representations of backbone geometry.1 The alphabet found to be most effective overall has seven states and is based on a count of Cβ atoms within a 14 Å‐radius sphere centered at the Cβ of a residue of interest. When incorporated into a hidden Markov model (HMM), this alphabet gave us a 38% performance boost in fold recognition and 23% in alignment quality. Proteins 2004. © 2004 Wiley‐Liss, Inc.
Automatic target selection for structural genomics on eukaryotes
Authors: Liu Jinfeng , Hegyi Hedi , Acton Thomas B. , Montelione Gaetano T. , Rost Burkhard
Published: March 2004

A central goal of structural genomics is to experimentally determine representative structures for all protein families. At least 14 structural genomics pilot projects are currently investigating the feasibility of high‐throughput structure determination; the National Institutes of Health funded nine of these in the United States. Initiatives differ in the particular subset of “all families” on which they focus. At the NorthEast Structural Genomics consortium (NESG), we target eukaryotic protein domain families. The automatic target selection procedure has three aims: 1) identify all protein domain families from currently five entirely sequenced eukaryotic target organisms based on their sequence homology, 2) discard those families that can be modeled on the basis of structural information already present in the PDB, and 3) target representatives of the remaining families for structure determination. To guarantee that all members of one family share a common foldlike region, we had to begin by dissecting proteins into structural domain‐like regions before clustering. Our hierarchical approach, CHOP, utilizing homology to PrISM, Pfam‐A, and SWISS‐PROT chopped the 103,796 eukaryotic proteins/ORFs into 247,222 fragments. Of these fragments, 122,999 appeared suitable targets that were grouped into >27,000 singletons and >18,000 multifragment clusters. Thus, our results suggested that it might be necessary to determine >40,000 structures to minimally cover the subset of five eukaryotic proteomes. Proteins 2004;55:000–000. © 2004 Wiley‐Liss, Inc.
X‐ray structural and simulation analysis of a protein mutant: The value of a combined approach
Authors: Mattos Carla , Cohen Justin D. , Green David F. , Tidor Bruce , Karplus Martin
Published: March 2004

The effect of the mutation Arg 96 to His on the stability of bacteriophage T4 lysozyme has been previously studied by calorimetric experiments, X‐ray crystallography, and free energy simulation techniques. The experimental and calculated values for the difference between the free energy of denaturation of the mutant and the wild type are in reasonable agreement. However, the two approaches led to different explanations for the loss in stability. To analyze the differences, a series of refinements based on the crystallographic data were performed, a number of aspects of the simulations were reexamined, and continuum electrostatic calculations were done to complement the latter. The results of those comparisons provide a better understanding of the origin of the free energy difference in this mutant. Furthermore, they show the importance of the combined use of simulations and crystallography for interpreting the effects of mutations on the energetics of the system. Proteins 2004. © 2004 Wiley‐Liss, Inc.
The determinants of carboxyl pKa values in turkey ovomucoid third domain
Authors: Li Hui , Robertson Andrew D. , Jensen Jan H.
Published: March 2004

A computational methodology for protein pKa predictions, based on ab initio quantum mechanical treatment of part of the protein and linear Poisson–Boltzmann equation treatment of the bulk solvent, is presented. The method is used to predict and interpret the pKa values of the five carboxyl residues (Asp7, Glu10, Glu19, Asp27, and Glu43) in the serine protease inhibitor turkey ovomucoid third domain. All the predicted pKa values are within 0.5 pH units of experiment, with a root‐mean‐square deviation of 0.31 pH units. We show that the decreased pKa values observed for some of the residues are primarily due to hydrogen bonds to the carboxyl oxygens. Hydrogen bonds involving amide protons are shown to be particularly important, and the effect of hydrogen bonding is shown to be nonadditive. Hydrophobic effects are also shown to be important in raising the pKa. Interactions with charged residues are shown to have relatively little effect on the carboxyl pKa values in this protein, in general agreement with experiment. Proteins 2004;55:000–000. © 2004 Wiley‐Liss, Inc.
The architecture of the binding site in redox protein complexes: Implications for fast dissociation
Authors: Crowley Peter B. , Carrondo Maria Arménia
Published: March 2004

Interprotein electron transfer is characterized by protein interactions on the millisecond time scale. Such transient encounters are ensured by extremely high rates of complex dissociation. Computational analysis of the available crystal structures of redox protein complexes reveals features of the binding site that favor fast dissociation. In particular, the complex interface is shown to have low geometric complementarity and poor packing. These features are consistent with the necessity for fast dissociation since the absence of close packing facilitates solvation of the interface and disruption of the complex. Proteins 2004;55:000–000. © 2004 Wiley‐Liss, Inc.
Accurate and efficient description of protein vibrational dynamics: Comparing molecular dynamics and Gaussian models
Authors: Micheletti Cristian , Carloni Paolo , Maritan Amos
Published: March 2004

Current all‐atom potential based molecular dynamics (MD) allows the identification of a protein's functional motions on a wide‐range of timescales, up to few tens of nanoseconds. However, functional, large‐scale motions of proteins may occur on a timescale currently not accessible by all‐atom potential based MD. To avoid the massive computational effort required by this approach, several simplified schemes have been introduced. One of the most satisfactory is the Gaussian network approach based on the energy expansion in terms of the deviation of the protein backbone from its native configuration. Here, we consider an extension of this model that captures in a more realistic way the distribution of native interactions due to the introduction of effective side‐chain centroids. Since their location is entirely determined by the protein backbone, the model is amenable to the same exact and computationally efficient treatment as previous simpler models. The ability of the model to describe the correlated motion of protein residues in thermodynamic equilibrium is established through a series of successful comparisons with an extensive (14 ns) MD simulation based on the AMBER potential of HIV‐1 protease in complex with a peptide substrate. Thus, the model presented here emerges as a powerful tool to provide preliminary, fast yet accurate characterizations of protein near‐native motion. Proteins 2004. © 2004 Wiley‐Liss, Inc.
Photoluminescence of one‐dimensional electron gases in cleaved‐edge overgrowth quantum wires
Authors: Kristukat C. , Gonñi A. R. , Bichler M. , Wegscheider W. , Abstreiter G. , Thomsen C.
Published: March 2004

We carried out micro‐photoluminescence studies of doped multiple quantum wire structures grown by the cleaved‐edge overgrowth technique in the GaAs/AlGaAs material system. The wires are defined in a quantum well whose potential is modulated by adjacent alternating negatively and positively charged layers. We observed strong band gap renormalization effects in the quantum wires indicating that they are densely populated. The measured recombination energies are in good agreement with a simple quantum mechanical calculation. Nevertheless, the design of the sample appears to be not suitable for light scattering studies of the one dimensional (1D) electron gas, for the 1D confinement strongly depends on photoexcitation. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Impurity‐related magnetism in the diluted magnetic semiconductors Pb1−xSnxTe:Yb
Authors: Skipetrov E. , Zvereva E. , Skipetrova L. , Kovalev B. , Volkova O. , Golubev A. , Slyn'ko E.
Published: March 2004

The effect of ytterbium impurity on the magnetic and galvanomagnetic properties of new diluted magnetic semiconductors Pb1−xSnxTe:Yb was investigated. Impurity‐related Curie–Weiss paramagnetism was revealed. The concentration of magnetic centers and the ytterbium impurity‐band occupancy as a function of impurity content were determined. The results are discussed assuming the formation of a ytterbium‐induced level under the valence‐band top and a variation of the magnetic centers concentration due to changing of the mutual arrangement of the valence band, impurity level and Fermi‐level position. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Lattice dynamics and phase transition in LaBGeO5
Authors: Smirnov M. B. , Menschikova A. V. , Kratochvilova‐Hruba I. , Zikmund Z.
Published: March 2004

A detailed analysis of the LaBGeO5 single crystal vibration spectra has been carried out. The lattice vibration calculation based on a short‐range model potential function provides the theoretical background of this study. The model function parameters are taken from ab initio quantum mechanic calculations of molecular clusters containing structural fragments. When applied to the lattice dynamics calculations the model satisfactorily reproduces the spectra of IR‐ and Raman‐active modes. The main goal of this lattice dynamics study was to find the proper atomic rearrangement associated with a ferroelectric phase transition. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical properties of Sm‐chelate containing methyl methacryate solution and its solid polymer matrix
Authors: Liang Hao , Zheng Zhiqiang , Zhang Qijin , Ming Hai , Chen Biao
Published: March 2004

From optical absorption spectra and using the Judd–Ofelt theory, the phenomenological parameters, Ω2, Ω4, and Ω6 of Sm(DBM)3(TOPO)2 containing methyl methacryate (MMA) solution and solid poly(methyl methacryate) (PMMA) matrix were obtained. The chemical structure of Sm‐chelate accounts for the nearly same Ω2 values in liquid solution and solid polymer matrix. The evaluation of the radiative properties of Sm‐chelate containing PMMA showed that the 4G5/2 → 6H9/2 transition of Sm3+ in polymer matrix is potential to be a laser transition.. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
2003 SOMMA KMS Meeting International Symposium on Magnetic Materials and Applications, Daejeon, Korea, 3–6 December 2003
Authors: Stobiecki Tomasz
Published: March 2004

Conference Reports are meant to offer an authoritative view on a recently held scientific meeting rather than a comprehensive list of the conference presentations. Authors are invited to describe what they feel were the most interesting contributions.

The full Proceedings of the 2003 SOMMA KMS Meeting will be published in phys. stat. sol. (a) and phys. stat. sol. (b) in Spring 2004. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Editorial: phys. stat. sol. (b) 241/5
Authors: Stutzmann Martin
Published: March 2004

Physica status solidi was founded in 1961 by a number of eminent solid state physicists as an attempt to overcome the iron curtain, which then separated East and West, at least in the field of science. Since that time our world has changed quite a bit, and so have the boundary conditions of science publishing. However, one thing has not changed: then as now, the general policy and development of a respectable scientific journal should be determined by a board of independent scientists, who volunteer to assume responsibility for the scientific content of the journal, to assure a fair and critical peer review process for all submitted manuscripts, and, in cases of conflict, to finally decide which papers will be published and which will not.

As a matter of fact, an international Board of Editors which consists of scientists coming from different countries and continents, with a good reputation in their respective community, and without any conflict of interest with the Publisher of the journal is, in my opinion, these days more important than ever. As our daily scientific work becomes increasingly specialized, but at the same time also increasingly interdisciplinary, we are more and more forced to trust the quality and reliability of published scientific results in the literature, without really having a chance to come to an independent opinion on our own. This is one of the reasons why the many recent cases of plagiarism, scientific misconduct, or outright fraud have caused such a high level of public awareness. It is quite clear that without a serious peer review there would be an even larger number of such cases in the literature, and that without the responsible action taken by concerned Journal Editors, many of the revealed cases probably would have remained “under the carpet”.

It is, therefore, a particular pleasure for me to introduce to you on the following pages the current Editorial Board of physica status solidi (b) in the form of a brief curriculum vitae, a photograph, and an e‐mail address (in case you want to contact our Editors directly!). Of course, since 1961 the Editorial Board of our journal has undergone many changes and will continue to do so, but we always have attempted to maintain a good balance between the different areas of solid state physics, between theory and experiment, and between different countries. And although nothing is perfect, I hope that you will find at least one or two board members, who are known to you through their contributions to the literature in solid state physics.

For me, this is the perfect occasion to thank all Members of the Editorial Board, past and present, for their advice, continuing support, and dedication! Vielen herzlichen Dank!
Conditional Lifetime Data Analysis Using the Limited Expected Value Function
Authors: Quigley John , Walls Lesley
Published: March 2004

Much failure, and other event, data are commonly highly censored. Consequently this limits the efficacy of many statistical analysis techniques. The limited expected value (LEV) function presents an alternative way of characterizing lifetime distributions. In essence the LEV provides a means of calculating a truncated mean time to failure (MTTF) (or mean time before failure (MTBF) if appropriate) that is adjusted at each of the censoring times and so appears potentially suitable for dealing with censored data structures. In theory, the LEV has been defined for many standard distributions, however its practical use is not well developed. This paper aims to extend the theory of LEV for typical censoring structures to develop procedures that will assist in model identification as well as parameter estimation. Applications to typical event data will be presented and the use of LEV in comparison with a selection of existing lifetime distributional analysis will be made based on some preliminary research. Copyright © 2004 John Wiley & Sons, Ltd.
On the Use of Imprecise Probabilities in Reliability
Authors: Coolen F. P. A.
Published: March 2004

Theory of imprecise probability generalizes classical probability theory, by assigning to each event an interval instead of a single number. In this paper, we briefly discuss this generalization and some recently suggested applications of imprecise probabilities in reliability. We also comment on challenges for research and applications. Copyright © 2004 John Wiley & Sons, Ltd.
Non‐parametric Predictive Inference for Age Replacement with a Renewal Argument
Authors: Coolen‐Schrijner P. , Coolen F. P. A.
Published: March 2004

We consider an age replacement problem with cost function based on the renewal reward theorem. However, instead of assuming a known probability distribution for the lifetimes, we apply Hill's assumption $A_{(n)}$ for predicting probabilities for the lifetime of a future item. Lower and upper bounds for the survival function of a future item are used, resulting in upper and lower cost functions. Minimizing these upper and lower cost functions to obtain the optimal age replacement times is simplified due to the special form of these functions.

To discuss some features of our approach, we first study the consequences of using $n$ equally spaced percentiles from a known distribution instead of $n$ observed data. Secondly, we report on a simulation study where the lifetimes are simulated from known distributions, so that the optimal replacement times corresponding to our approach can be compared with the theoretical optimal replacement times. Copyright © 2004 John Wiley & Sons, Ltd.
Assessing the Impact of Preventive Maintenance Based on Censored Data
Authors: Bedford Tim
Published: March 2004

Recent work in the field of competing risks enables us to start an assessment of the impact of preventive maintenance on the failure characteristics of a piece of equipment. Competing risk is the term given when more than one factor conspires to take a piece of equipment out of service. A simple example of this is given by preventive maintenance and failure. Each could occur to a piece of equipment but only one actually can. The preventive maintenance time may censor the unobserved latent failure time, thus ensuring that the statistical analysis of the failure times is made more difficult. Maintenance optimization models require knowledge of the underlying failure distribution. The Kaplan–Meier estimator (and other similar techniques) is commonly used to remove the effect of the censoring variable on the estimate of the distribution of the variable of interest. When the censoring variable is preventative maintenance, however, it is most unlikely that the assumptions of the Kaplan–Meier estimator (independence between the latent failure and preventive maintenance times) are valid. In this paper we give an overview of some of the different methods which have recently emerged in this area. These make different assumptions about the relation between PM and failure to allow the PM censoring to be ‘removed’. Potentially, these methods would allow us to look at changing maintenance strategies. Although they are in the early stages of development they do already allow us to quantify the effect of some changes. Copyright © 2004 John Wiley & Sons, Ltd.
Spectroscopic constants and molecular properties of CN−, SiH−, PO−, SO−, SF−, and SiS−: Density functional study
Authors: Midda S. , Das A. K.
Published: March 2004

Spectroscopic constants and molecular properties of selected diatomic anions namely CN−, SiH−, PO−, SO−, SF−, and SiS− in their ground states have been studied in detail using the hybrid HF/DF B3LYP method. The consistency of the calculated values has been verified with four different basis sets, with improved quality. The spectroscopic constants and molecular properties calculated with the aug‐cc‐pVTZ basis set agree very well with the experimental and theoretical values wherever available. Most of the spectroscopic constants and molecular properties of the selected diatomic anions, particularly the spectroscopic constants and molecular properties of SO− and SiS− are reported for the first time. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Three‐electron two‐center bonding in cycloimmonium ylides
Authors: Karafiloglou P. , Surpateanu G.
Published: March 2004

We explore the possibility that a 3‐electron‐2‐center bonding exists in cycloimmonium ylides. To detect this bonding in a polyatomic system, 3‐electron‐1‐hole density operators, characterizing a Pauling 3‐electron bond, are used in the framework of second quantization formalism. The weights of 3‐electron resonance structures are calculated and compared with the weights of 2‐electron structures for the ylide bond of pyridinium dicyanomethylide; the correlations of (↑↓) and (↑) electronic events, involved in the 3‐electron resonance structures, are also investigated. The calculations are performed in various approximation levels, and both orthogonal and nonorthogonal natural atomic orbitals are adopted. All calculations show that a 3‐electron bond exists between N and C atoms of ylide bond, but this bonding is not extended in C atoms of the pyridinium group. The interactions of α,β electrons (at the configuration interaction [CI] level) increase the localization of electrons, the weights of 3‐electron resonance structures, and thus the probability for 3‐electron bonding. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
New model of the electronic structure of the [Mo6X8(CN)6]6− clusters (XS, Se) based on the study of electron density distribution in the inner part of the Mo6 polyhedron
Authors: Baranovski V. I. , Korolkov D. V.
Published: March 2004

The geometric structure and bonding in [Mo6S8(CN)6]6− cluster were studied on the basis of quantum chemical ab initio and DFT (B3LYP) calculations with different basis sets. The geometry parameters of the Mo6S8 core are in good agreement with the available crystal structure data. The electron density in the inner part of the Mo6 octahedron is almost constant (∼0.04–0.06 e/au3). There is also noticeable electron density on the edges and faces of the Mo6S8 polyhedron. The model of the electronic structure of the cluster under consideration starts from the mobile electrons moving in the potential well of the spherical symmetry. The resulting states are classified according to orbital quantum number l (e.g., 1s, 1p, 1d, 1f). Subsequent crystal field splitting leads to observable consequence of the one electron states of the Oh point group symmetry. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Bonding in FHF−, (HF)2, and FHF
Authors: Davidson Ernest R.
Published: March 2004

Bonding in FHF−, (HF)2, and FHF is compared from the molecular orbital and electrostatic bonding viewpoint. The electrostatic force is dominant in the formation of FHF− and HF dimer. Exchange repulsion dominates in preventing the formation of FHF and leads to a D∞h transition state for H exchange. At the D∞h stationary points for FHF− and FHF the electronic structure can be understood using delocalized symmetry orbitals, but this delocalization is not the primary driving force along the potential energy surface leading to these structures. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Theoretical study of reaction mechanism for CH2CHX(XH, F, Cl) with ozone
Authors: Li Lai‐Cai , Deng Ping , Xu Ming‐Hou , Wong Ning‐Bew
Published: March 2004

In this work, we study the reaction mechanism of the CH2CHX(XH, F, Cl) with ozone reactions, using ab initio MP2 method at 6‐311++g** basis set level. The geometric configurations of reactants, intermediates, transition states, and products were optimized, and the energies were obtained at the QCISD(T)/6‐311++G** level. The transition states and intermediates of the reactions were verified by the vibrational analysis. The results show that the ozonolysis of ethylene and its derivatives is reasonable and believable along the Criegee mechanism. The results also show that the activation energies of the controlling steps along the fluoroethylene and chloroethylene with ozone reaction pathways were lower than that along the ethylene with ozone reaction pathway. That is to say, the derivatives of ethylene have the higher activity to react with ozone and deplete the ozone layer. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Weakest bound electron potential model theory
Authors: Zheng Neng‐Wu , Wang Tao , Ma Dong‐Xia , Zhou Tao , Fan Jing
Published: March 2004

Differing from the self‐consistent field (SCF) method, in which an N‐electron atom problem is treated as a one‐electron problem with the use of a basic assumption of average potential, we develop a unified weakest bound electron potential model (WBEPM) theory. The relativistic form of the theory is given for the first time and is combined with the nonrelativistic form introduced in previous work to arrive at the unified WBEPM theory. The theory has two main ideas. First, from consideration of viewpoints of the dynamic successive ionization and the choice of zero of energy in quantum mechanics, an N‐electron atom system can be subdivided into N subsystems only containing a weakest bound electron (WBE) in each of subsystems. For each subsystem by separation of WBE and non‐weakest bound electrons (NWBE), WBE is believed to move in an approximate potential field provided by a “core” consisting of NWBEs and the nucleus. Thus, a complicated N‐electron problem is reduced to a simple analytical one‐electron problem of WBE. Second, the properties of an atom, such as total wave function, total energy, atomic energy levels, and transition between energy levels, can be investigated through the behaviors of a WBE or several WBEs, or up to all WBEs. Several excellent illustrative results show that the theory is capable of attaining very good computational accuracy. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Spin‐coupled study of addition reactions of singlet dihalocarbenes with ethene
Authors: Blavins Joshua J. , Cooper David L. , Karadakov Peter B.
Published: March 2004

Modern valence bond theory, in its spin‐coupled form, is used to examine the electronic rearrangements that take place during the gas‐phase additions of singlet CF2 and of singlet CCl2 to ethene. Both reactions are found to follow homolytic pathways, during which the ethene π‐bond breaks and the orbitals that were originally involved in this bond interact with the singlet orbital pair on the carbene. The formation of the two new σ bonds that close the cyclopropane ring proceeds in a markedly asynchronous manner, so that the systems attain considerable diradical character, as quantified by the composition of the active‐space spin‐coupling pattern. The rearrangement of the electron spins from a reactant‐like form to one better suited to the product takes place much later in the case of the reaction between CCl2 and ethene than in the corresponding reaction of CF2. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Symbolic calculation in chemistry: Selected examples
Authors: Barnett Michael P. , Capitani Joseph F. , von zur Gathen Joachim , Gerhard Jürgen
Published: March 2004

A selective classified bibliography of symbolic computation in some areas of chemistry is provided together with some examples of computer algebra algorithms and techniques to facilitate future joint work of chemists and computer scientists. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Dynamic headspace: a single‐step extraction for isotopic analysis of μg/L concentrations of dissolved chlorinated ethenes
Authors: Morrill Penny L. , Lacrampe‐Couloume Georges , Lollar Barbara Sherwood
Published: March 2004

In this study a dynamic headspace method was developed to measure the carbon isotope values of dissolved chlorinated ethenes at μg/L concentrations. A gas chromatograph/combustion/isotope ratio mass spectrometer (GC/C/IRMS) was modified to include a headspace extraction system followed by a cryogenic trap. Extracting headspace from a 160 mL vial with 80 mL of aqueous solution and 40 g of NaCl for 8–12 min resulted in accurate and reproducible δ13C values for trichloroethene (TCE) and cis‐1,2‐dichloroethene (cDCE) at concentrations of 50–75 μg/L. Based on these results a conservative lower limit of quantitation of 38 μg/L can be calculated for these compounds. For more volatile compounds such as tetrachloroethene (PCE) and vinyl chloride (VC), field data analyzed using this method indicate a lower limit of quantitation in the tens of μg /L range. Copyright © 2004 John Wiley & Sons, Ltd.
Characterization of a model Phillips catalyst by mass spectrometry
Authors: Di Croce Pascal Gabriel , Aubriet Frédéric , Chéty‐Gimondo Rachel , Muller Jean‐François , Grange Paul
Published: March 2004

A model Phillips catalyst for ethylene polymerization, prepared by spin coating a Cr(III)(Cr(acac)3) precursor on a silicon wafer, was submitted to an oxidative activation. Laser ablation Fourier transform mass spectrometry provided direct information on molecular species at the silicon wafer surface during activation. At 350°C the chromium precursor was degraded, while chromium oxide species were formed. The chromium concentration decreased with temperature. The activated model catalyst was active for ethylene polymerization. Using complementary techniques (Fourier transform infrared spectroscopy, laser desorption/ionization mass spectrometry), the polymer was identified as crystalline polyethylene. After 1 h of polymerization at 160°C, dome‐like structures were observed by atomic force microscopy. Their morphologies were constituted of regions of parallel aligned lamellae of polymer. Copyright © 2004 John Wiley & Sons, Ltd.
Linking protein fractionation with multidimensional monolithic reversed‐phase peptide chromatography/mass spectrometry enhances protein identification from complex mixtures even in the presence of abundant proteins
Authors: Wienkoop Stefanie , Glinski Mirko , Tanaka Nobuo , Tolstikov Vladimir , Fiehn Oliver , Weckwerth Wolfram
Published: March 2004

Recently, multidimensional shotgun proteomics has proven to be an alternative technology able to identify hundreds of proteins from single samples. Two major limitations of the technology are the presence of high abundance proteins (e.g. RUBISCO in plant leaf tissue) and the enormous number of co‐eluting peptides that overstrain the loading and resolving capacity of conventional particle‐packed columns as well as the capacity of electrospray ionisation due to ion suppression. Here, the coupling of fast performance liquid chromatography (FPLC) pre‐fractionation of an Arabidopsis leaf protein extract and subsequent two‐dimensional liquid chromatography/mass spectrometry with improved resolution using a monolithic silica C18 capillary column allowed the identification of 1032 unique proteins in a single 4 mg total protein plant leaf tissue sample. The reassignment of peptide IDs to distinct FPLC protein fractions enhances the identification procedure, especially in the case of present protein isoforms. The proposed strategy is useful to detect proteins otherwise not seen in conventional multidimensional chromatography/mass spectrometry approaches. Copyright © 2004 John Wiley & Sons, Ltd.
Specific recognition of DNA bulge structure by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry
Authors: Chen Yu‐Ju , Chen Po‐Jui , Wang Hsueh‐Ting , Cheng Chien‐Chung
Published: March 2004

This study reports a novel approach utilizing an octahedral CoII(HAPP)(TFA)2 reagent in the presence of H2O2 with analysis by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOFMS) to serve as an efficient probe for bulged DNA structures. Elucidation of DNA bulge‐specific recognition pathways and cleavage mechanisms is demonstrated by characterization of bulge‐specific cleavage products and other backbone lesion fragments. The cleavage specificity of CoII(HAPP)(TFA)2/H2O2 arises from sugar oxidative strand scission, for which the position of the abstracted hydrogen is unambiguously determined as the 4′‐H of the deoxyribose moiety. Furthermore, differentiation between bulge‐specific recognition and diffusion‐controlled non‐selective cleavage can be clarified through time‐dependent MALDI‐TOFMS studies. The present results demonstrate that MALDI‐TOFMS can be a sensitive and efficient technique for complex mechanistic studies of this kind, providing information for future rational drug design targeting bulged DNA structures. Copyright © 2004 John Wiley & Sons, Ltd.
Structural characterization of novel chemotactic and mastoparan peptides from the venom of the social wasp Agelaiapallipes pallipes by high‐performance liquid chromatography/electrospray ionization tandem mass spectrometry
Authors: Mendes Maria Anita , Monson de Souza Bibiana , Delazari dos Santos Lucilene , Palma Mario Sergio
Published: March 2004

High‐performance liquid chromatography/electrospray ionization mass spectrometry (HPLC/ESI‐MS) and high‐performance liquid chromatography/electrospray ionization tandem mass spectrometry (HPLC‐ESI‐MS/MS) techniques were applied for the detection, purification, monitoring, and sequencing of two novel and biologically active peptides occurring at very low levels in the venom of the wasp Agelaia pallipes pallipes. These peptides were sequenced under LC/ESI‐MS/MS conditions and designated as Agelaia‐CP (I/L‐L‐G‐T‐I‐L‐G‐L‐L‐K‐G‐I/L‐NH2, MW 1207.8 Da) and Agelaia‐MP (I/L‐N‐W‐L‐K‐L‐G‐K‐A‐I‐I‐D‐A‐I/L‐NH2, MW 1565.0 Da). The peptide Agelaia‐CP showed no hemolytic activity, but it behaved as a mast cell degranulator and induced a potent chemotaxis in polymorphonucleated leukocyte (PMNL) cells, typical of a wasp chemotactic peptide. The peptide Agelaia‐MP showed both powerful mast cell degranulation and hemolysis of washed rat red blood cells, and is thus assigned as a new member of the mastoparan family of peptides. Both peptides seem to be directly involved in the strong inflammatory reactions associated with wasp stings. Copyright © 2004 John Wiley & Sons, Ltd.