bluuebunny/crossref_metadata_2025 huggingface dataset:
Solventless Acid‐Free Synthesis of Mesostructured Titania: Nanovessels for Metal Complexes and Metal Nanoclusters
Authors: Dag Ö. , Soten I. , Çelik Ö. , Polarz S. , Coombs N. , Ozin G.A.
Published: February 2003

A new and highly reproducible method to obtain mesostructured titania materials is introduced in this contribution. The mesostructured titania is obtained by employing self‐assembled structures of non‐ionic alkyl‐poly(ethylene oxide) surfactants as templates. The materials are produced without additional solvents such as alcohols, or even water. Only the titanium(IV) ethoxide and the surfactant (C12EO10) are needed. Water, in the form of that attached to the surfactant and from the atmosphere, induces growth of titania nanoclusters in the synthesis sol. It is indicated that these nanoclusters interact with the surfactant EO‐head groups to form a new titanotropic amphiphile. The new amphiphiles self‐assemble into titanium nanocluster–surfactant hybrid lyotropic phases, which are transformed to the final mesostructured materials by further condensation of the titania network. The titania materials can be obtained also with noble‐metal particles immobilized in the mesostructured framework. It is seen that when different metal salts are used as the metal precursors, different interactions with the titania walls are found. The materials are characterized by X‐ray diffraction (XRD), polarization optical microscopy (POM), transmission electron microscopy (TEM), UV‐vis spectroscopy, and micro‐Raman analysis.
Nanocrystalline Transition‐Metal Oxide Spheres with Controlled Multi‐Scale Porosity
Authors: Grosso D. , de A.A. Soler‐Illia G.J. , Crepaldi E.L. , Charleux B. , Sanchez C.
Published: February 2003

This article presents original multi‐scale porous nanocrystalline transition‐metal oxide materials (MO2, where M = Ti, Zr, Ce) that have many potential applications. They were prepared through a one step method that combines sol–gel chemistry, multi‐scale templating approaches, aerosol processing, and specific treatments. The final material presents itself as spheres of controlled diameter, made of a periodically organized mesoporous crystalline network that surrounds spherical macropores, in which each single porosity can be easily and independently adjusted. In addition, a porosity gradient can be generated. The strategy highlighted here can be easily applied to many hierarchically structured sol–gel derived materials. Moreover, this process can easily be scaled up, which could lead to a breakthrough in the industrial production of innovative multiscale porosity materials.
Non‐Destructive Readout of the Photochromic Reactions of Diarylethene Derivatives Using Infrared Light
Authors: Uchida K. , Saito M. , Murakami A. , Nakamura S. , Irie M.
Published: February 2003

Non‐destructive readout of an image using IR light on a polymer film containing a photochromic diarylethene was successively carried out. 1,2‐Bis(2‐methyl‐6‐phenyl‐1‐benzothiophen‐3‐yl)hexafluorocyclopentene was found to exhibit a remarkable IR spectral change around 1590 cm–1 upon photoirradiation, as demonstrated in the Figure.
The Combination of Colloid‐Controlled Heterogeneous Nucleation and Polymer‐Controlled Crystallization: Facile Synthesis of Separated, Uniform High‐Aspect‐Ratio Single‐Crystalline BaCrO4 Nanofibers
Authors: Yu S.‐H. , Cölfen H. , Antonietti M.
Published: February 2003

Uniform, separated BaCrO4 single‐crystalline nanofibers with high aspect ratio (> 5000, see Figure) can be fabricated at room temperature in aqueous solution using a double hydrophilic block copolymer as structure‐directing agent and introducing colloidal nucleation agents. Such fibers represent a model case for advanced polymer fillers and the exploration of quasi‐1D nanostructures with interesting electrical, optical, or catalytic properties.
Ordered Mosaic Nanocomposites in Anodic Porous Alumina
Authors: Masuda H. , Abe A. , Nakao M. , Yokoo A. , Tamamura T. , Nishio K.
Published: February 2003

A mosaic consisting of pillars of two kinds of metal, gold and nickel, has been deposited on porous alumina substrates. A sequence of barrier layer application, selective penetration of the barrier, and metal deposition can be manipulated to control the arrangement and density of the composites. An array of Au (brighter) and Ni cylinders is shown in the Figure.
Clinical and genetic aspects of trigonocephaly: A study of 25 cases
Authors: Azimi Cyrus , Kennedy Shelley J. , Chitayat David , Chakraborty Pranesh , Clarke Joe T.R. , Forrest Christopher , Teebi Ahmad S.
Published: February 2003

We reviewed 25 patients ascertained through the finding of trigonocephaly/metopic synostosis as a prominent manifestation. In 16 patients, trigonocephaly/metopic synostosis was the only significant finding (64%); 2 patients had metopic/sagittal synostosis (8%) and in 7 patients the trigonocephaly was part of a syndrome (28%). Among the nonsyndromic cases, 12 were males and 6 were females and the sex ratio was 2 M:1 F. Only one patient with isolated trigonocephaly had an affected parent (5.6%). All nonsyndromic patients had normal psychomotor development. In 2 patients with isolated metopic/sagittal synostosis, FGFR2 and FGFR3 mutations were studied and none were detected. Among the syndromic cases, two had Jacobsen syndrome associated with deletion of chromosome 11q 23 (28.5%). Of the remaining five syndromic cases, different conditions were found including Say‐Meyer syndrome, multiple congenital anomalies and bilateral retinoblastoma with no detectable deletion in chromosome 13q14.2 by G‐banding chromosomal analysis and FISH, I‐cell disease, a new acrocraniofacial dysostosis syndrome, and Opitz C trigonocephaly syndrome. The last two patients were studied for cryptic chromosomal rearrangements, with SKY and subtelomeric FISH probes. Also FGFR2 and FGFR3 mutations were studied in two syndromic cases, but none were found. This study demonstrates that the majority of cases with nonsyndromic trigonocephaly are sporadic and benign, apart from the associated cosmetic implications. Syndromic trigonocephaly cases are causally heterogeneous and associated with chromosomal as well as single gene disorders. An investigation to delineate the underlying cause of trigonocephaly is indicated because of its important implications on medical management for the patient and the reproductive plans for the family. © 2003 Wiley‐Liss, Inc.
Sperm segregation patterns by fluorescence in situ hybridization studies of a 46,XY,t(2;6) heterozygote giving rise to a rare triploid product of conception with a 69,XXY,t(2;6)(p12;q24)der(6)t(2;6)(p12;q24)pat karyotype
Authors: Lim A.S.T. , Lim T.H. , Kee S.K. , Chieng R. , Tay S.K.
Published: February 2003

A blighted ovum diagnosed initially by ultrasound was determined to be a partial hydatidiform mole with a 69,XXY,t(2;6)(p12;q24)der(6)t(2;6)(p12;q24)pat karyotype by cytogenetic analysis. The triploid state arose through dispermy in which both spermatozoa carried rearranged chromosomes, one carrying a balanced translocation through alternate segregation and the other an unbalanced derivative chromosome 6 through adjacent 1 segregation. Segregation analysis of 7,000 spermatozoa from the father was performed with a three‐color fluorescence in situ hybridization (FISH) protocol using α‐satellite 6, telomeric 2p, and telomeric 6q probes. Segregation frequencies of normal and balanced products (alternate segregation), adjacent 1, adjacent 2, and 3:1 were 49.9%, 42.4%, 2.5%, and 4.2%, respectively. The high percentage of alternate segregation is consistent with the knowledge of their preferential outcome. However, the high incidence of adjacent 1 sperm highlights the abnormality risk. Alternate and adjacent 1 segregations (92.3%) accounted for the observed rearranged chromosomes in the triploid. The most viable imbalanced combination would be the one carrying the der(6) chromosome, but since the unbalanced segment comprises 3.6% of the haploid autosomal length (HAL), no risk of a viable imbalanced offspring is indicated. However, an increased likelihood of recurrent miscarriages is likely, and this is confirmed by the couple's two earlier miscarriages. Sperm segregation patterns of translocation carriers determined by FISH can help in ascertaining expected and unexpected karyotypes. The high frequency of adjacent 1 products shows that the presence of the additional derivative chromosome in the partial mole, though rare in occurrence, should be less surprising. © 2002 Wiley‐Liss, Inc.
100 Jahre Didehydroaromaten
Authors: Wenk Hans Henning , Winkler Michael , Sander Wolfram
Published: February 2003

Seit nunmehr 100 Jahren stehen Didehydroaromaten, die sich formal durch Entfernen zweier Wasserstoffatome von einem aromatischen Ring ableiten, im Blickfeld der Organischen Chemie. Während ortho‐Didehydrobenzol als reaktive Zwischenstufe der nucleophilen aromatischen Substitution in jedem einführenden Lehrbuch über Reaktionsmechanismen Erwähnung findet, galten die meta‐ und para‐Isomere bis vor relativ kurzer Zeit als ausgesprochene Exoten. Diese Situation hat sich durch die Entdeckung der Endiin‐Cytostatika, einer vielversprechenden Klasse von Antitumor‐Wirkstoffen, schlagartig geändert und das Interesse vieler Arbeitsgruppen weltweit wachgerufen. Didehydroaromaten und damit im Zusammenhang stehende Systeme zählen heute zu den am intensivsten untersuchten Verbindungen überhaupt. Dennoch sind viele Aspekte der Chemie dieser reaktiven Intermediate nach wie vor unverstanden. In diesem Aufsatz skizzieren wir die historische Entwicklung und stellen aktuelle Tendenzen heraus.
Sensory Principles of Higher Plants
Authors: Weiler Elmar W.
Published: February 2003

Plants respond to a broad variety of stimuli from the interior of their body and from the outside environment. A revolution in our knowledge of the sensory capabilities of plants took place during the last decade, thanks to the consequent application of the tools of molecular genetics and the focusing of most work, in a world‐wide effort, on a single, representative, higher plant: Arabidopsis thaliana. This review concentrates on the complete sensory periphery of higher plants, with focus placed on the principles rather than the details, and such systems that have been functionally identified unambiguously. Higher plants are no less fascinating, no less complex, and no less sensitive than animals, even man, with respect to their sensory capabilities. Plants constantly monitor their environment and their interior situation by using a stunning array of sensory systems, that are mostly different from those of animals or man.
Cover Picture: One Century of Aryne Chemistry (Angew. Chem. Int. Ed. 5/2003)
Authors: Wenk Hans Henning , Winkler Michael , Sander Wolfram
Published: February 2003

A century of aryne chemistry has not dampened the interest in this class of reactive intermediates. The cover picture shows the structure of a calicheamicin–DNA complex, the “warhead” of which is a cyclic enediyne unit (highlighted). The biological activity of the enediyne cytostatics is based on the depicted Bergman cyclization of the enediyne to a didehydrobenzene biradical. More about these short‐lived species is given by Sander et al. on pp. 502 ff.
Modeling O2 transport within engineered hepatic devices
Authors: McClelland Randall E. , MacDonald Jeffrey M. , Coger Robin N.
Published: February 2003

Predicting and improving oxygen transport within bioartificial liver (BAL) devices continues to be an important engineering challenge since oxygen is one of the critical nutrients necessary for maintaining hepatocyte viability and function. Such a computational model would not only help predict outcomes but it would also allow system modifications to be analyzed prior to developing experimental protocols. This would help to facilitate future design improvements while reducing both experimental time and capital resource costs, and is the focus of the current study. Specifically, a computational model of O2 transport through collagen and microporous collagen ECMs is analyzed for hollow fiber (HF), flat plate (FP), and spheroid BAL designs. By modifying the O2 boundary conditions, hepatocyte O2 consumption levels, O2 permeability of the ECM, and ECM void fractions, O2 transport predictions are determined for each system as a function of time and distance. Accuracy of the predictive model is confirmed by comparing computational vs. experimental results for the HF BAL system. The model's results indicate that O2 transport within all three BAL designs can be improved significantly by incorporating the enhancement technique. This technique modifies a diffusion‐dominant gel ECM into a porous matrix with diffusive and convective flows that mutually transport O2 through the ECMs. Although tortuous pathways increase the porous ECM's overall effective length of O2 travel, the decreased transport resistances of these pathways allow O2 to permeate more effectively into the ECMs. Furthermore, because the HF design employs convective flow on both its inner and outer ECM surfaces, greater control of O2 transport through its ECM is predicted, as compared with the single O2 source inputs of the flat plate and spheroid systems. The importance of this control is evaluated by showing how modifying the O2 concentration and/or transfer coefficients of the convective flows can affect O2 transport. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 82: 12–27, 2003.
A new VFA sensor technique for anaerobic reactor systems
Authors: Pind Peter F. , Angelidaki Irini , Ahring Birgitte K.
Published: February 2003

A key parameter for understanding and controling the anaerobic biogas process is the concentration of volatile fatty acids (VFA). However, this information has so far been limited to off‐line measurements using labor‐intensive methods. We have developed a new technique that has made it possible to monitor VFA on‐line in one of the most difficult media: animal slurry or manure. A novel in situ filtration technique has made it possible to perform microfiltration inside a reactor system. This filter enables sampling from closed reactor systems without large‐scale pumping and filters. Furthermore, due to its small size it can be placed in lab‐scale reactors without disturbing the process. Using this filtration technique together with commercially available membrane filters we have constructed a VFA sensor system that can perform automatic analysis of animal slurry at a frequency as high as every 15 minutes. Reproducibility and recovery factors of the entire system have been determined. The VFA sensor has been tested for a period of more than 60 days with more than 1000 samples on both a full‐scale biogas plant and lab‐scale reactors. The measuring range covers specific measurements of acetate, propionate, iso‐/n‐butyrate and iso‐/n‐valerate ranging from 0.1 to 50 mM (6–3000 mg). The measuring range could readily be expanded to more components and both lower and higher concentrations if desired. In addition to the new VFA sensor system, test results from development and testing of the in situ filtration technique are being presented is this article. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 82: 54–61, 2003.
Inhibition of an activated Ras protein with genetically selected peptide aptamers
Authors: Kurtz Stephen E. , Esposito Kim , Tang Weimin , Menzel Rolf
Published: February 2003

Mutant alleles of Ras maintain an activated, GTP‐bound conformation and relay mitogenic signals that cannot be turned off. A genetic selection in Saccharomyces cerevisiae was used to identify peptide aptamers that suppress the growth arrest phenotype of an activated Ras allele. Peptide aptamers were expressed as C‐terminal fusions to glutathione‐S‐transferase. Modifications that alter the coding capacity of the peptide aptamer indicate it is necessary for Ras2‐Val19 suppression. Aptamer expression also reduces the elevated levels of cAMP and suppresses the heat shock sensitivity characteristic of Ras‐activated yeast cells. The peptide aptamer retains suppressor activity when fused to thioredoxin. The peptide aptamer expression strategy described here indicates that aptamers presented as unconstrained peptides have functional capacity in vivo. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 82: 38–46, 2003.
Interpartical Breakage on Fine Hard Materials by Single and Multiple Compression
Authors: Reichardt Y. , Schönert K.
Published: February 2003

The interparticle breakage of fine feed fractions of quartz, zircon silicate, smelted corundum and silicon carbide is investigated by stressing a particle bed either once with a pressure between 600 and 1800 MPa or several times with a pressure of 100 to 700 MPa. The multiple compression is performed in a press unit with two piston pairs orientated perpendicularly to each other and acting alternatively. Each successive stressing, therefore, disaggregates the compacted bed of the preceding compression. The size‐reduction depends only on the specific energy absorption and not on the pressure level, at which the energy is introduced. The data allows an estimate of the specific comminution energy without any machinery losses for producing a product with a wanted fineness characterized by the maximum particle size to be obtained. These results are much less than the energy consumption of stirred ball mills.
Templateless Assembly of Molecularly Aligned Conductive Polymer Nanowires: A New Approach for Oriented Nanostructures
Authors: Liu Jun , Lin Yuehe , Liang Liang , Voigt James A. , Huber Dale L. , Tian Zhengrong R. , Coker Eric , Mckenzie Bonnie , Mcdermott Matthew J.
Published: February 2003

Although oriented carbon nanotubes, oriented nanowires of metals, semiconductors and oxides have attracted wide attention, there have been few reports on oriented polymer nanostructures such as nanowires. In this paper we report the assembly of large arrays of oriented nanowires containing molecularly aligned conducting polymers (polyaniline) without using a porous membrane template to support the polymer. The uniform oriented nanowires were prepared through controlled nucleation and growth during a stepwise electrochemical deposition process in which a large number of nuclei were first deposited on the substrate using a large current density. After the initial nucleation, the current density was reduced stepwise in order to grow the oriented nanowires from the nucleation sites created in the first step. The usefulness of these new polymer structures is demonstrated with a chemical sensor device for H2O2, the detection of which is widely investigated for biosensors. Finally, we demonstrated that controlled nucleation and growth is a general approach and has potential for growing oriented nanostructures of other materials.
Polymorphism of 1,2‐Bis(2‐methyl‐5‐p‐methoxyphenyl‐3‐thienyl)perfluorocyclopentene and Photochromic Reactivity of the Single Crystals
Authors: Morimoto Masakazu , Kobatake Seiya , Irie Masahiro
Published: February 2003

Four polymorphic crystals were obtained by recrystallization of 1,2‐bis(2‐methyl‐5‐p‐methoxyphenyl‐3‐thienyl)perfluorocyclopentene (1 a) from hexane. All crystals underwent photochromic reactions upon alternate irradiation with ultraviolet (λ=370 nm) and visible light (λ>500 nm). The photocyclization quantum yields were found to be close to unity irrespective of the crystal types, while the photocycloreversion quantum yields were different as much as four times depending on the conformation of the closed‐ring isomers in the crystals.
Redox‐Induced Coordination Isomerization of a Phosphoniobenzophospholide
Authors: Gudat Dietrich , Lewall Burhanshah , Nieger Martin , Detmer Ilka , Szarvas László , Saarenketo Pauli , Marconi Guido
Published: February 2003

1‐Triphenylphosphoniobenzo[c]phospholide 1 reacts with [M(CO)5Br] (M = Mn, Re) and [Mn(CO)3(naphthalene)][BF4] to give complexes cis‐[M(CO)4(1)Br] (5 a,b) and [Mn(CO)3(1)][BF4] (6 a[BF4]), respectively, featuring η1(P)‐ and η5(π)‐coordination of the phosphole ring. The corresponding reactions with [M2(CO)10] proceed with conservation of the metal–metal bond and yield, depending on the reaction temperature, dinuclear complexes [M2(CO)8(1)] (M=Mn, 7 a) or [M2(CO)6(1)2] (M=Mn, Re, 8 a,b) with μ2‐bridging η1(P):η2(PC) coordination of the phosphole moiety. All complexes formed were characterized by spectroscopic data; 5 b, 6 a[BF4], and 8 a,b were characterized by X‐ray diffraction studies as well. The structural and 31P NMR data of the dinuclear manganese complex 8 a suggest that the interaction between the metal atoms and the η2‐bound PC double bond moieties is dominated by the L→M charge‐transfer contribution; this hints at a very low back‐donation ability of the central M2(CO)6 fragment. Investigation of the reactions of the Mn complexes 6 a and 8 a with Mg or ferrocenium hexafluorophosphate ([Fc][PF6]), respectively, revealed that the chemically reversible mutual interconversion between both species was feasible. Likewise, oxidation of the rhenium complex 8 b with [Fc][PF6] gave spectroscopic evidence for the formation of a Re analogue of 6 a. Electrochemical studies suggested that the oxidation 8 a→2 6 a involves two consecutive single‐electron‐transfer steps, the first of which is electrochemically reversible and produces a metastable radical cation that is detectable by ESR spectroscopy. The mutual interconversion between 6 a and 8 a represents the first case of a reversible coordination isomerization of a phosphaarene that is triggered by a redox process and might stimulate further studies directed at the use of dinuclear phosphaarene complexes in redox‐catalysis.
Prevalence of the Alkyl/Phenyl‐Folded Conformation in Benzylic Compounds C6H5CH2‐X‐R (X=O, CH2, CO, S, SO, SO2): Significance of the CH/π Interaction as Evidenced by High‐Level Ab Initio MO Calculations
Authors: Takahashi Osamu , Kohno Yuji , Saito Ko , Nishio Motohiro
Published: February 2003

Ab initio MO calculations were carried out to examine the conformational energies of various benzylic compounds C6H5CH2XR (X=O, CH2, CO, S, SO, SO2; R=CH3, C2H5, iC3H7, tC4H9) at the MP2/6‐311G(d,p)//MP2/6‐31G(d) level. Rotamers with R/Ph in gauche relationship are generally more stable than the R/Ph anti rotamers. In these stable geometries, the interatomic distance in the interaction of α‐ or β‐CH in the alkyl group and the ipso‐carbon atom of the phenyl ring is short. The computational results are consistent with experimental data from supersonic molecular jet spectroscopy on 3‐n‐propyltoluene and NMR and crystallographic data on structurally related ketones, sulfoxides, and sulfones. In view of this, the alkyl/phenyl‐congested conformation of these compounds has been suggested to be a general phenomenon, rather than an exception. The attractive CH/π interaction has been suggested to be a dominant factor in determining the conformation of simple aralkyl compounds.
Recent trends and racial/ethnic differences in the incidence and treatment of ductal carcinoma in situ of the breast in California women
Authors: Innos Kaire , Horn‐Ross Pamela L.
Published: February 2003

BACKGROUND

The rapid increase in the incidence of ductal carcinoma in situ (DCIS) of the breast in the U.S. has been associated with the widespread adoption of screening mammography. Little is known regarding the incidence and treatment of DCIS in women of racial/ethnic groups other than white and black. The current investigation examined recent trends and racial/ethnic differences in the incidence and treatment of DCIS in California.

METHODS

All cases of DCIS diagnosed in women age ≥ 40 years in California between 1988–1999 were included. Age‐adjusted incidence rates for white, black, Hispanic, and Asian‐Pacific Islander women were calculated using the 2000 U.S. female population as the standard. The estimated annual percent change (EAPC) in the rates was calculated using least squares regression.

RESULTS

The average annual age‐adjusted incidence of DCIS (1988–1999) was 45.3 per 100,000 in white women, 35.0 in black women, 30.9 in Asian‐Pacific Islander women, and 21.8 in Hispanic women. Although a steady increase in the incidence of DCIS was noted in all racial/ethnic groups over the study period, Asian‐Pacific Islander women were found to have experienced the steepest increase (EAPC = 9.1%), particularly in the age group 50–64 years (EAPC = 12.0%). The DCIS incidence was reported to increase with age in white, black, and Hispanic women, but remained fairly constant after the age of 50 years in Asian‐Pacific Islanders. The proportion of women with DCIS treated with mastectomy decreased from 53% in 1988 to 32% in 1999. Younger women and Asian‐Pacific Islander women reportedly were more likely to undergo mastectomy.

CONCLUSIONS

Considerable differences by race/ethnicity and age were observed in DCIS incidence and the change in the incidence in California between 1988 and 1999. Further information is needed to determine whether these differences are because of differential utilization of screening mammography or biologic characteristics of DCIS lesions. Cancer 2003;97:1099–106. © 2003 American Cancer Society.

DOI 10.1002/cncr.11104
Survival and functional outcome of children with hypothalamic/chiasmatic tumors
Authors: Fouladi Maryam , Wallace Dana , Langston James W. , Mulhern Raymond , Rose Susan R. , Gajjar Amar , Sanford Robert A. , Merchant Thomas E. , Jenkins Jesse J. , Kun Larry E. , Heideman Richard L.
Published: February 2003

BACKGROUND

The management of children with hypothalamic (H) and/or chiasmatic (C) tumors remains controversial. We evaluated the impact of clinical and neuroimaging parameters and primary therapy on overall (OS) and progression‐free (PFS) survival and on neuroendocrine and neurocognitive outcome in children with H and/or C tumors.

METHODS

Records were reviewed for 73 children with H and/or C tumors treated at St. Jude Children's Research Hospital between October 1981 and December 1999.

RESULTS

Thirty‐six patients received irradiation or chemotherapy immediately postdiagnosis and 37 were observed. The 6‐year OS and PFS rates were 86 ± 5%; and 36 ± 7%, respectively. The 6‐year PFS rates for the irradiation, chemotherapy, and observation groups were 69 ± 16%, 12 ± 11%, and 37 ± 9%, respectively. In multivariate analysis, intracranial NF1 lesions (P= 0.015) and initial irradiation (P= 0.056) led to better PFS rates. There was no difference in OS between those initially treated or observed. Mean serial intelligence quotient (IQ) scores were 86 and 86 at diagnosis and at 6 years later, respectively. Patients younger than 5 years old had a lower mean IQ score at diagnosis (79.1) than older patients (96.3;P= 0.003). Patients who were irradiated at diagnosis had a significantly higher cumulative incidence of endocrinopathy at 3 years (P= 0.008).

CONCLUSIONS

Overall survival for children with H and/or C tumors is excellent. Initial treatment with radiation and the presence of intracranial NF1 lesions were positive predictors of PFS. Mean IQ is significantly compromised at diagnosis, but does not change over time or with irradiation. Overall survival is not affected by initial observation. We recommend observation in asymptomatic patients, platinum‐based chemotherapy in younger patients, and irradiation in older symptomatic patients. Cancer 2003;97:1084–92. © 2003 American Cancer Society.

DOI 10.1002/cncr.11119
Prognostic implication of clinical, radiologic, and pathologic features in patients with anaplastic gliomas
Authors: Tortosa Avelina , Viñolas Núria , Villà Salvador , Verger Eugènia , Gil Juan M. , Brell Marta , Caral Lluís , Pujol Teresa , Acebes Juan J. , Ribalta Teresa , Ferrer Isidre , Graus Francesc
Published: February 2003

BACKGROUND

The clinical evolution of anaplastic glioma (anaplastic astrocytoma, oligodendroglioma, and oligoastrocytoma) is variable. Previous studies merged patients with anaplastic glioma and the much more common glioblastoma multiforme. Therefore, the conclusions on prognostic factors reflected in part the consequences of an analysis in a heterogeneous population.

METHODS

To identify clinical, neuroradiologic, pathologic, and molecular factors with prognostic significance, we analyzed 95 treated patients with a histologic diagnosis of anaplastic glioma. Variables included age, gender, clinical manifestations at diagnosis (seizures, focal neurologic deficit, and cognitive changes), computed tomographic (CT) scan characteristics (diffuse, ring, and no enhancement), tumor location, extent of resection, histopathology, postoperative Karnofsky performance status (KPS) score, adjuvant chemotherapy, tumor response, proliferation index (Ki‐67 expression), and p53, p16, pRb, and epidermal growth factor receptor immunohistochemical expression.

RESULTS

Ninety‐five patients with a histologic diagnosis of anaplastic astrocytoma (73%), anaplastic oligoastrocytoma (16.6%), or anaplastic oligodendroglioma (10.4%) constituted the basis of this study. Median overall survival was 29 months. Multivariate analysis revealed that an age of 49 years or younger (P < 0.03), postoperative KPS score of 80 or higher (P < 0.007), absence of ring enhancement (P = 0.03), and a proliferation index of 5.1% or lower (P = 0.044) were independently associated with longer survival. The presence of an oligodendroglial component was associated with better prognosis in the univariate analysis (P = 0.009), although this lost power in the multivariate analysis.

CONCLUSIONS

In addition to previously recognized prognostic variables such as age and KPS score, CT ring enhancement and tumor proliferation index were identified as independent predictors of survival in a homogeneous series of patients with anaplastic gliomas. Cancer 2003;97:1063–71. © 2003 American Cancer Society.

DOI 10.1002/cncr.11120
Primitive neuroectodermal tumors in the central nervous system following cranial irradiation
Authors: Hader Walter J. , Drovini‐Zis Katerina , Maguire John A.
Published: February 2003

BACKGROUND

Radiation induced intracranial neoplasms are uncommon but well described and include gliomas, meningiomas, and sarcomas. The development of primitive neuroectodermal tumors (PNETs) following prophylactic craniospinal irradiation has been infrequently reported previously. The authors present four additional cases of PNETs that developed after previous cranial irradiation.

METHODS

Four patients who had previously been irradiated were determined to have PNETs of the central nervous system characterized by histopathologic and immunohistochemical features. The average patient age at diagnosis of the initial tumors and cranial irradiation was 17 years. The PNETs developed 5, 11, 11, and 18 years after completion of radiation.

RESULTS

Three patients had posterior fossa tumors, one pilocytic astrocytoma, one low grade astrocytoma, and one malignant ependymoma, which had been diagnosed and treated in childhood. Two of those patients developed supratentorial PNETs and the third a cerebellar hemispheric PNET. The fourth patient developed a posterior fossa PNET following irradiation for a temporal astrocytoma, which was initially diagnosed and resected at 37 years of age. Mean survival was 12 months after diagnosis.

CONCLUSIONS

The development of PNETs after cranial irradiation may be more common than thought previously and should be considered in the differential diagnosis of irradiation induced neoplasms. Survival after diagnosis of these radiation induced PNETs was short, and this may reflect an inability to provide standard therapy used for primary PNETs. Cancer 2003;97:1072–6. © 2003 American Cancer Society.

DOI 10.1002/cncr.11121
Expression of survivin in astrocytic tumors
Authors: Kajiwara Yoshinori , Yamasaki Fumiyuki , Hama Seiji , Yahara Kaita , Yoshioka Hiroyuki , Sugiyama Kazuhiko , Arita Kazunori , Kurisu Kaoru
Published: February 2003

BACKGROUND

Astrocytic tumors are the most common tumors of the central nervous system. The mechanisms of genetic change of astrocytic tumors have not been understood completely. Recently, survivin has been identified as a member of the inhibitor‐of‐apoptosis family. Survivin expression is considered an important prognostic factor of many tumors.

METHODS

The authors investigated 43 astrocytic tumors (8 diffuse astrocytomas; 15 anaplastic astrocytomas; 20 glioblastomas). The authors examined survivin mRNA expression in tumor specimens by reverse transcriptase‐polymerase chain reaction amplification. The authors analyzed the relationship between survivin expression and other molecular changes commonly found in astrocytic tumors [p53 alteration, overexpression of epidermal growth factor receptor (EGFR), and bcl‐2 expression].

RESULTS

Thirty‐four of 43 (79.1%) astrocytic tumors expressed survivin. The distributions included 3 of 8 (37.5%) diffuse astrocytomas, 13 of 15 (86.7%) anaplastic astrocytomas, and 18 of 20 (90.0%) glioblastomas. Expression of survivin (P = 0.0057) and EGFR (P = 0.0112) was significantly associated with malignant grade of astrocytic tumors, but expression of p53 (P = 0.1893) and bcl‐2 (P = 0.2552) was not. Furthermore, patients with survivin‐positive astrocytic tumors had significantly shorter overall survival times compared with patients who had survivin‐negative tumors (P = 0.0271).

CONCLUSIONS

Survivin expression in astrocytic tumors varies with histologic malignancy and may play an important role in the oncogenesis and progression of astrocytic tumors. These data suggest that survivin has great potential as a therapeutic target in astrocytic tumors. Cancer 2003;97:1077–83. © 2003 American Cancer Society.

DOI 10.1002/cncr.11122
Evaluation of an instrument to assess the needs of men diagnosed with prostate carcinoma
Authors: Duke Janine M. , Treloar Carla J. , Byles Julie E.
Published: February 2003

BACKGROUND

This study was conducted to evaluate a self‐administered questionnaire developed to measure the needs experienced by men diagnosed with prostate carcinoma (the Prostate Cancer Needs Questionnaire [PCNQv1.1]). The PCNQv1.1 was constructed in two parts. Part 1 measures the needs at diagnosis and initial treatment and Part 2 measures current needs.

METHODS

A random sample of 650 men diagnosed with prostate carcinoma who were being treated by a urologist of the Hunter Urology Group in Newcastle, New South Wales, Australia, were invited to participate in the study. They were sent by post the self‐administered PCNQv1.1. Completed questionnaires were received from 385 men. Information provided on 100 additional men was considered ineligible.

RESULTS

The principal components method of factor analysis with varimax orthogonal rotation identified eight factors with eigenvalues greater than 1, which accounted for 61.7% of the variance in Part 1 of the PCNQv1.1. Likewise, six factors were identified in Part 2, which accounted for 63.5% of the variance. Internal reliability coefficients (Cronbach alpha) were adequate for identified factors with values ranging from 0.70 to 0.88 for Part 1 and from 0.71 to 0.87 for Part 2. Test‐retest reliability was acceptable with intraclass correlation coefficients ranging from 0.61 to 0.78 for Part 1 and from 0.60 to 0.82 for Part 2.

CONCLUSIONS

These results suggest that the PCNQv1.1 is a valid and reliable instrument to assess the needs experienced by men diagnosed with prostate carcinoma. Cancer 2003;97:993–1001. © 2003 American Cancer Society.

DOI 10.1002/cncr.11156
Positive surgical margins and ipsilateral breast tumor recurrence predict disease‐specific survival after breast‐conserving therapy
Authors: Meric Funda , Mirza Nadeem Q. , Vlastos Georges , Buchholz Thomas A. , Kuerer Henry M. , Babiera Gildy V. , Singletary S. Eva , Ross Merrick I. , Ames Frederick C. , Feig Barry W. , Krishnamurthy Savitri , Perkins George H. , McNeese Marsha D. , Strom Eric A. , Valero Vicente , Hunt Kelly K.
Published: February 2003

BACKGROUND

The current study identified determinants of systemic recurrence and disease‐specific survival (DSS) in patients with early‐stage breast carcinoma treated with breast‐conserving surgery and radiation therapy (breast‐conserving therapy, or BCT).

METHODS

The study population consisted of 1,043 consecutive women with Stages I or II breast carcinoma who underwent BCT between 1970 and 1994. Clinical and pathologic characteristics evaluated included age, tumor size, tumor grade, estrogen and progesterone receptor status, surgical margins, axillary lymph node involvement, and use of adjuvant therapy.

RESULTS

At a median follow‐up time of 8.4 years, 127 patients (12%) had developed an ipsilateral breast tumor recurrence (IBTR), and 184 patients (18%) had developed a systemic recurrence. On multivariate logistic regression analysis, tumor size greater than 2 cm, positive lymph nodes, lack of adjuvant tamoxifen therapy, and positive margins (odds ratio [OR], 3.7; 95% confidence interval [CI], 1.1‐12.3; P = 0.034) were predictors of systemic recurrence. When IBTR was added into the model, adjuvant therapy and surgical margins were not independent predictors; however, IBTR was an independent predictor of systemic recurrence (IBTR vs. no IBTR; OR, 6.2; 95% CI, 3.1‐12.3; P < 0.001). The 10 year DSS rate after BCT was 87%. On multivariate Cox proportional hazards model analysis, the following factors were independent predictors of poor DSS: tumor size greater than 2 cm (vs. ≤ 2 cm; relative risk [RR], 2.3; 95% CI, 1.2‐4.3; P = 0.010), negative progesterone receptor status (vs. positive; RR, 2.7; 95% CI, 1.4‐5.1; P = 0.003), positive margins (vs. negative; RR, 3.9; 95% CI, 1.4‐11.5; P = 0.011), and IBTR (vs. no IBTR; RR, 5.5; 95% CI, 2.8‐11.0; P < 0.001).

CONCLUSIONS

Positive surgical margins and IBTR are predictors of systemic recurrence and disease‐specific survival after BCT. Aggressive local therapy is necessary to ensure adequate surgical margins and to minimize IBTR. Cancer 2003;97:926–33. © 2003 American Cancer Society.

DOI 10.1002/cncr.11222
An estimation of software reliability models based on EM algorithm
Authors: Okamura Hiroyuki , Watanabe Yasuhiro , Dohi Tadashi , Osaki Shunji
Published: February 2003

In this paper, a new estimation method is proposed for the model parameters of a software reliability model based on the EM (Expectation‐Maximization) principle. The debugging of the software including finite faults can be described by a generalized order statistics model. The generalized order statistics model is expressed by a nonhomogeneous Poisson process (NHPP) and the maximum likelihood method can usually be used for estimation of model parameters. However, since in this method the simultaneous logarithmic likelihood equation is numerically solved, it is not always effective from the viewpoints of algorithm stability and computation effort.

The EM algorithm proposed here is a simple iteration method, which consists of several updating equations. The algorithm can accurately and stably obtain the maximum likelihood estimates. In this paper, specific EM algorithms are also derived for the cases where the occurrence of a software failure follows the exponential distribution, second‐order Erlang distribution, Rayleigh distribution, Pareto distribution, and log normal distribution. Further, by using real data, the EM algorithm is compared with the method based on the simultaneous logarithmic likelihood equation in terms of the stability of the solution. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 86(6): 29–37, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.10058
New Insight into the Mechanism of the Conjugate Addition of Benzenethiol to Cyclic and Acyclic Enones and of the Corresponding Uranyl−Salophen‐Catalysed Version
Authors: van Axel Castelli Valeria , Dalla Cort Antonella , Mandolini Luigi , Reinhoudt David N. , Schiaffino Luca
Published: February 2003

A thorough kinetic investigation of the triethylamine‐catalysed addition of benzenethiol to 2‐cyclopenten‐1‐one in chloroform shows that the highest energy transition state is a complex of thiol, enone, and base in a 1:1:1 ratio, but whether formation or disruption of the enolate−triethylammonium ion‐pair intermediate is rate‐limiting is uncertain. Intervention of a second thiol molecule in the assembly of the transition‐state complex is ruled out, at least at thiol concentrations not exceeding 0.1−0.2M. Thiol addition is accelerated significantly by uranyl−salophen complex1and its diphenyl derivative2. The complicated kinetics are described to high precision by means of ad hoc integrated rate equations in which associations to the metal catalyst of the enone reactant and addition product are taken into account. The kinetics are consistent with a four‐body transition‐state complex, whose formation results from the reaction of a (weak) thiol−base complex with a (strong) enone−uranyl−salophen complex. Open‐chain and cyclic enones react at similar rates and respond to the presence of metal catalyst in much the same way. The relative catalytic efficiencies of ethyldimethylamine, triethylamine, and quinuclidine are determined essentially by differences in base strength, rather than steric bulk, in both the presence and absence of a metal complex. Only with the use of the relatively bulky Hünig’s base is an adverse steric influence apparent, which is particularly severe in the reaction catalysed by the sterically demanding2. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Direct Access to Furanosidic Eight‐Membered Ulosonic Esters from cis‐α,β‐Epoxy Aldehydes
Authors: Sugisaki Claudia H. , Ruland Yvan , Baltas Michel
Published: February 2003

Direct access to bicyclic precursors of octulosonic acids is achieved by treatment of differentially (or not) protected γ,δ‐bis(silyloxy) cis‐α,β‐epoxy aldehydes with ethyl 2‐(trimethylsilyloxy)‐2‐propenoate in the presence of boron trifluoride−diethyl ether. An X‐ray crystallographic structure of a bicycle (compound 33a) was obtained and used to determine the absolute configurations of the different stereogenic centers and thus the diastereoselective preference of the aldol reaction (syn) and the regioselectivity of the epoxide ring‐opening (C‐6 atom). Functionalization and opening of the bicyclic compound to afford octulosonic analogues in their furanoside forms was studied. An octulosonic 8‐phosphate analogue has been synthesized. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Asymmetric Synthesis of a New Helix‐Forming β‐Amino Acid: trans‐4‐Aminopiperidine‐3‐carboxylic Acid
Authors: Schinnerl Marina , Murray Justin K. , Langenhan Joseph M. , Gellman Samuel H.
Published: February 2003

We report a synthesis of a protected derivative of trans‐4‐aminopiperidine‐3‐carboxylic acid (APiC). The route provides either enantiomer. All intermediates are purified by crystallization, and large‐scale preparation is therefore possible. An analogous route provides either enantiomer of trans‐2‐aminocyclohexanecarboxylic acid (ACHC). We have previously shown that β‐peptide oligomers containing ACHC adopt a helical conformation defined by 14‐membered C=O(i)···H−N(i − 2) hydrogen bonds (“14‐helix”). Here we show that APiC residues can be incorporated into the 14‐helix. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
A Stereoselective Synthesis of Five‐ and Six‐Membered Cyclic β‐Amino Acids
Authors: Perlmutter Patrick , Rose Mark , Vounatsos Filisaty
Published: February 2003

The cyclic β‐amino acids 1 and 2 have been prepared in a short and stereoselective manner. The synthesis features a diastereoselective thioester enolate/imine condensation reaction and a ring‐closing metathesis as key processes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Poly(Ferrocenylalkylammonium): A Molecular Electrode Material for Dihydrogenphosphate Sensing
Authors: Reynes Olivier , Royal Guy , Chaînet Eric , Moutet Jean‐Claude , Saint‐Aman Eric
Published: February 2003

By virtue of strong ion‐paring interactions that are reinforced following oxidation of ferrocene moieties to ferrocenium form, films synthesized by oxidative polymerization of pyrrole‐containing (ferrocenylmethyl)trialkylammonium cations are able to electrochemically sense the dihydrogenphosphate anion in organic electrolytes. Strong and selective affinity of these cationic polymer films towards H2PO4− was evidenced from FT‐IR and EQCM experiments. Clear two‐wave differential pulse voltammetry features allow the amperometric titration of this anion.
Retention modeling and resolution optimization for a group ofN‐phenylpyrazole derivatives in micellar electrokinetic chromatography using empirical and physicochemical models
Authors: García‐Ruiz Carmen , Jiménez Olga , Marina Maria L.
Published: February 2003

The optimization of the separation resolution for a group ofN‐phenylpyrazole derivatives in micellar electrokinetic chromatography (MEKC) as a function of the separation buffer composition (surfactant and organic modifier concentration) has been performed. In order to achieve our purpose, the first step has been the prediction of the migration times of the electroosmotic flow (t0) and micelles (tm), and the retention factors of solutes (k), as a function of surfactant (sodium dodecyl sulfate) and alcohol (n‐propanol orn‐butanol) concentrations, by means of empirical equations. Also, some physicochemical models have been applied to relate the retention factors to the surfactant and the organic modifier concentrations in order to optimize the separation resolution and to increase our knowledge of the separation process. Finally, a comparison of the resolution optimization through the use of the physicochemical and empirical models selected has been made in order to obtain the optimum separation buffer composition for the separation of a group of 17N‐phenylpyrazole derivatives as test solutes.
Synergistic effects of ion‐pairing in the enantiomeric separation of basic compounds with cyclodextrin derivatives in nonaqueous capillary electrophoresis
Authors: Servais Anne‐Catherine , Fillet Marianne , Abushoffa Adel M. , Hubert Philippe , Crommen Jacques
Published: February 2003

The enantiomeric separation of various kinds of basic pharmaceuticals has been investigated in nonaqueous capillary electrophoresis (NACE) systems using an ion‐pairing reagent in combination with cyclodextrins (CDs). The simultaneous addition to the methanolic background electrolyte (BGE) of (+)‐S‐camphorsulfonate or alkanesulfonates and an anionic β‐cyclodextrin derivative, heptakis(2,3‐dimethyl‐6‐sulfato)‐β‐cyclodextrin (HDMS‐β‐CD), led to partial or complete enantioresolution in most cases. In the absence of ion‐pairing reagent, the enantiomeric resolution obtained with this CD derivative was most often completely lost or strongly reduced, indicating the important role of ion‐pairing in the chiral recognition mechanism in these NACE systems. The influence of the nature and concentration of the counterion and the anionic CD derivative on the enantioseparation of basic compounds was studied. Synergistic effects between these two kinds of charged additives were clearly observed.
Mathematical modelling of adsorption and transport processes in capillary electrochromatography: Open‐tubular geometry
Authors: Pačes Martin , Kosek Juraj , Marek Miloš , Tallarek Ulrich , Seidel‐Morgenstern Andreas
Published: February 2003

A mathematical modelling approach for open‐tubular capillary electrochromatography is presented. The spatially one‐dimensional model takes into account (i) a coupling of (non)linear adsorption of positively or negatively charged analyte molecules (at a negatively charged capillary inner surface) with the equilibrium electrokinetics at this solid‐liquid interface, (ii) mobile phase transport by electroosmosis and pressure‐driven flow, as well as (iii) transport of species by electrophoresis and molecular diffusion. Under these conditions the local zeta‐potential and electroosmotic mobility become a function of the concentration of the charged analyte. The resulting inhomogeneity of electroosmotic flow through the capillary produces a compensating pore pressure as requirement for incompressible mobile phase flow (i.e., for constant volumetric flow along the capillary). The results of the simulations are discussed in view of the surface‐to‐volume ratio of the capillary lumen, the analyte concentration (in combination with a Langmuir isotherm for the adsorption process), and buffer effects.