bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantitation of DNA from Flow Cytometry Analysis Using Fluorescent Probe
Authors: Higuchi Akon , Murayama Yukiyo , Tsukamoto Yasuhisa , Kojima Toshinori , Kitamura Hanako
Published: November 2004

A reproducible method to quantify DNA in DNA and protein solutions at ppb levels using flow cytometry analysis is reported herein. After DNA and protein solutions were dyed with fluorescent probe (PicoGreenTM) intercalating, flow cytometric scattergrams of DNA at fluorescent intensities of 525 nm and 575 nm showed a higher intensity of emission at 525 nm than those of proteins. DNA quantitation was performed using calf thymus DNA with two standard curves. The high standard curve showed a semi-logarithmic plot from 1 to 50 ppb with a correlation coefficient of 0.993, whereas the low standard curve described the second-power equation from 0.1 to 5 ppb DNA with a correlation coefficient of 0.998. A flow cytometry analysis of the DNA concentration was powerful for estimating the DNA concentration in a protein solution containing salts, such as saline, because the present flow cytometry analysis showed less than a 37% decline when the DNA solution contained 0.15 mol/L NaCl. The DNA content in albumin, cellulase, γ-globulin, and pepsin was estimated to be 0.078 ± 0.006, 0.26 ± 0.04, 3.0 ± 0.4, and 1.2 ± 0.1 μg-DNA/g-protein (n = 4), respectively, based on flow cytometry analysis of the protein solutions.
Palladium-Catalyzed Oxidative Carbonylation of 1-Alkynes into 2-Alkynoates with Molecular Oxygen as Oxidant
Authors: Izawa Yusuke , Shimizu Isao , Yamamoto Akio
Published: November 2004

A new preparative method to produce alkyl 2-alkynoates from 1-alkynes in alcohol under atmospheric pressure of CO at room temperature was developed with palladium–phosphine catalysts, using molecular oxygen as an oxidant. On the basis of the behavior of model complexes such as methoxycarbonylpalladium and alkynylpalladium complexes, we propose a mechanism accounting for the catalytic carbonylation of alkynes through an intermediate having the both methoxycarbonyl and alkynyl ligands that liberates methyl 2-alkynoates and a Pd(0) species on reductive elimination. The oxidation of Pd(0) to Pd(II) species in the presence of a halide ion was confirmed to proceed cleanly with molecular oxygen as the oxidant. On the basis of the findings on homogeneous catalysts, a heterogeneous catalytic system using Pd/C has also been developed.
γ-Cyclodextrin-Bicapped C60-Mediated Asymmetric Reduction of Ketones with NaBH4
Authors: Nishimura Takahiro , Nakajima Mitsuru , Maeda Yasunari , Uemura Sakae , Takekuma Shin-ichi , Takekuma Hideko , Yoshida Zen-ichi
Published: November 2004

A supramolecular γ-cyclodextrin-bicapped C60-mediated asymmetric reduction of prochiral alkyl aryl ketones using NaBH4 as a reducing reagent affords chiral sec-alcohols with moderate enantioselectivity.
One-Pot Synthesis of 12-Hydroxy-12H-benzo[b]thioxanthene-6,11-diones from 1,4-Naphthoquinone and o-Acylbenzenethiols
Authors: Kobayashi Kazuhiro , Umakoshi Hironobu , Matsunaga Akihiro , Tanmatsu Miyuki , Morikawa Osamu , Konishi Hisatoshi
Published: November 2004

The title benzo[b]thioxanthenequinone derivatives could be prepared in one-pot via a sequential conjugate addition and an aldol-type reaction between 1,4-naphthoquinone and o-acylbenzenethiols, followed by oxidation with 1,4-naphthoquinone or air.
50th Anniversary Article: Organizational Behavior, Strategy, Performance, and Design in Management Science
Authors: Boudreau John W.
Published: November 2004

This article provides a personal perspective on the themes and topics that have emerged in research published by the department of organizational behavior, in the first 50 years of Management Science. A review of articles accepted by the department suggests several themes that reflect broad objectives, such as “improving management science models,” or distinguishing points of view or assumptions, such as “treating organizations as decision-making entities.” The research is summarized through topics and subtopics that classify the subjects and findings of the research, identifying the relative popularity of the topics, and their contribution to each of the themes. The pattern suggests that as a “behavioral” department in a journal characterized by managerial practice, optimization, and the context of real work organizations, research is uniquely grounded in applications, solutions, and work consequences in ways that are less prevalent in typical outlets for behavioral research. The article concludes by suggesting that there are ample signs of convergence across departments in the journal. Scholars in organizational behavior increasingly recognize that the context provided by other management disciplines provides essential insights. Likewise, scholars in other management disciplines increasingly recognize the value of integrating behavioral theories and findings into their frameworks and models.
Diffusion Approximations for a Multiclass Markovian Service System with “Guaranteed” and “Best-Effort” Service Levels
Authors: Maglaras Constantinos , Zeevi Assaf
Published: November 2004

This paper considers a Markovian model of a service system motivated by communication and information services. The system has finite processing capacity and offers multiple grades of service. The highest priority users receive a “guaranteed” processing rate, while lower priority users share residual capacity according to their priority level and therefore may experience service degradation (hence the term “best effort”). This paper focuses on performance analysis for this class of systems. We consider the Halfin-Whitt heavy-traffic regime, where the arrival rate and system processing capacity both grow large in a way that the traffic intensity approaches one. We first derive a multidimensional diffusion approximation for the system dynamics and subsequently obtain a more tractable diffusion limit based on an intuitive “perturbation approach.” This method enables us to compute various closed form approximations to steady-state as well as transient congestion-related performance measures. Numerical examples illustrate the accuracy of these approximations.
Combination of General Antithetic Transformations and Control Variables
Authors: Ben-Ameur Hatem , L'Ecuyer Pierre , Lemieux Christiane
Published: November 2004

Several methods for reducing the variance in the context of Monte Carlo simulation are based on correlation induction. This includes antithetic variates, Latin hypercube sampling, and randomized version of quasi-Monte Carlo methods such as lattice rules and digital nets, where the resulting estimators are usually weighted averages of several dependent random variables that can be seen as function evaluations at a finite set of random points in the unit hypercube. In this paper, we consider a setting where these methods can be combined with the use of control variates and we provide conditions under which we can formally prove that the variance is minimized by choosing equal weights and equal control variate coefficients across the different points of evaluation, regardless of the function (integrand) that is evaluated.
Revenue Management of Flexible Products
Authors: Gallego Guillermo , Phillips Robert
Published: November 2004

A flexible product is a menu of two or more alternative, typically substitute, products offered by a constrained supplier using a sales or booking process. The supplier reserves the right to assign customers who purchase a flexible product to one of the alternatives at a time near the end of the booking process. An example would be an airline offering a morning flight consisting of specific flights serving the same market. Flexible products are currently offered by a number of industries including air cargo, tour operators, and Internet advertising. Flexible products have the advantage of increasing overall demand and enabling better capacity utilization at the cost of potentially cannibalizing high-fare demand for specific products. This paper introduces the concept of flexible products and derives conditions and algorithms for the management of a single flexible product consisting of two specific products. We use numerical simulation to illustrate the benefits from offering flexible products and discuss extension of the approach to more general settings.
Issues in Real-Time Fleet Management
Authors: Gendreau Michel , Potvin Jean-Yves
Published: November 2004

In this editorial comment, new issues in real-time fleet management arising from the advent of Internet-based services and the integration of transportation activities within the supply chain are introduced.
The A Priori Dynamic Traveling Salesman Problem with Time Windows
Authors: Larsen Allan , Madsen Oli B. G. , Solomon Marius M.
Published: November 2004

In this paper we examine the traveling saleman problem with time windows for various degrees of dynamism. In contrast to the static problem, where the dispatcher can plan ahead, in the dynamic version, part or all of the necessary information becomes available only during the day of operation. We seek to minimize lateness and examine the impact of this criterion choice on the distance traveled. Our focus on lateness is motivated by the problem faced by overnight mail service providers. We propose a real-time solution method that requires the vehicle, when idle, to wait at the current customer location until it can service another customer without being early. In addition, we develop several enhanced versions of this method that may reposition the vehicle at a location different from that of the current customer based on a priori information on future requests. The results we obtained on both randomly generated data and on a real-world case study indicate that all policies proved capable of significantly reducing lateness. Our results also show that this can be accomplished with only small distance increases. The basic policy outperformed the other methods primarily when lateness and distance were equally minimized and proved very robust in all environments studied. When only lateness was considered, the policy to reposition the vehicle at a location near the current customer generally provided the largest reductions in average lateness and the number of late customers. It also produced the least extra distance to be traveled among the relocation policies.
The Dynamic Assignment Problem
Authors: Spivey Michael Z. , Powell Warren B.
Published: November 2004

There has been considerable recent interest in the dynamic vehicle routing problem, but the complexities of this problem class have generally restricted research to myopic models. In this paper, we address the simpler dynamic assignment problem, where a resource (container, vehicle, or driver) can serve only one task at a time. We propose a very general class of dynamic assignment models, and propose an adaptive, nonmyopic algorithm that involves iteratively solving sequences of assignment problems no larger than what would be required of a myopic model. We consider problems where the attribute space of future resources and tasks is small enough to be enumerated, and propose a hierarchical aggregation strategy for problems where the attribute spaces are too large to be enumerated. Finally, we use the formulation to also test the value of advance information, which offers a more realistic estimate over studies that use purely myopic models.
On positive operators involving a certain class of generating functions
Authors: Doğru O. , Özarslan M. A. , Taşdelen F.
Published: November 2004

In this paper we introduced the general sequence of linear positive operators via generating functions. Approximation properties of these operators are obtained with the help of the Korovkin Theorem. The order of convergence of these operators computed by means of modulus of continuity Peetre’s K-furictiorial and the elements of the usual Lipschitz class. Also we introduce the r-th order generalization of these operators and we evaluate this generalization by the operators defined in this paper. Finally we give some applications to differential equations.
A larger class than the Deák one for the coincidence of some notions of quasi-uniform completeness using pairs of filters
Authors: Andrikopoulos A.
Published: November 2004

Different types of quasi-uniform completeness are shown to coincide in certain uniformly weakly regular spaces. This result generalizes Deák’s result in [4] which answers to the question of Fletcher and Hunsaker in [8].
Filiations between the Electronic Spectra of C60 and Its Adduct Derivatives: A Rationalization
Authors: Leach Sydney
Published: November 2004

Considerable similarities are observed between the absorption spectra in the 200–800‐nm region of C60 and its n‐adduct derivatives (n = 1 − 6), in spite of the fact that two π‐electrons are lost for each adduct. The persistence in the adduct derivatives of the main energy and transition strength characteristics of the allowed and forbidden electronic transitions of C60 is rationalized with a relatively simple model. The filial relation between these spectra is discussed on three levels of increasing physical refinement: (i) the electronic states and transitions resulting from a free‐electron, spherical shell model of C60; (ii) the effects of an icosahedral potential on such a model; and (iii) the effects of π‐electron loss and symmetry lowering due to the addends. The results show that similar, and related, orbital transitions are involved in the absorption spectra in the 200–800‐nm region of C60 and its adduct derivatives, albeit mildly affected by changes in molecular symmetry and in the size of the π‐conjugation region.
Energy Landscape Analysis of Protein Dimers
Authors: Levy Yaakov , Papoian Garegin A. , Onuchic José N. , Wolynes Peter G.
Published: November 2004

Many cellular functions are carried out by proteins that are bound together in multiprotein complexes. The binding between two highly flexible proteins to form homodimers is studied here using energy landscape theory and simulations based on a perfectly funneled energy landscape. With the aim to survey the range of binding mechanisms, two sets of homodimers were selected based on the experimental knowledge of whether stable monomers are needed for binding to take place. We find that the binding mechanism can be predicted based on the structure of the complex subunits alone. On average, the theory predicts a lower stability for subunits that are less compact and less hydrophobic, indicating, in agreement with their experimental classification, that their folding will be coupled to their binding. On the other hand, when a monomeric intermediate is experimentally found, the predicted stability of the monomers is comparable to that of known folded proteins. Furthermore, when dimerization is coupled to monomer folding, the interface is more hydrophobic.
A theoretical study of membrane constraint in polymer‐electrolyte fuel cells
Authors: Weber Adam Z. , Newman John
Published: November 2004

A mathematical model is developed that examines the effect of having a constrained membrane in a fuel cell. During operation, a polymer‐electrolyte fuel‐cell membrane is prone to swell but is unable to do so by system design. This builds up a stress that affects transport in, and the properties of, the membrane. This report is the first to incorporate such effects into a macrohomogeneous model. Both the physical and mathematical effects are described. Results include the magnitude of constraint, the change in water content of the membrane attributed to constraint, and one‐dimensional simulations showing the effect of constraint on the water balance of the fuel cell. The paper demonstrates the need for considering membrane constraint both in modeling and experimental studies of fuel cells. © 2004 American Institute of Chemical Engineers AIChE J, 50: 3215–3226, 2004
Modeling the steady flow of yield‐stress fluids in packed beds
Authors: Balhoff Matthew T. , Thompson Karsten E.
Published: November 2004

Network modeling has been performed to obtain quantitative and predictive results of the flow of yield‐stress fluids in packed beds. Physically representative networks were used as the basis for the modeling, which have a one‐to‐one correspondence to computer‐generated packed beds of spheres. The networks are able to account for the interconnectivity, heterogeneity, and converging/diverging geometry that are inherent in porous media. The approach can be used to model a wide range of non‐Newtonian fluids, but the emphasis is for yield‐stress fluids that can be represented using a Bingham model. For these fluids, a threshold pressure gradient is required to initiate flow, and flow at low pressure gradients is characterized by critical percolation behavior. Quantitative results of superficial velocity vs. pressure gradient are presented, and are compared to traditional bundle‐of‐tubes models, as well as limited experimental data available in the literature. Important differences are observed between the network model and the constitutive models. These are attributed mainly to heterogeneity and converging/diverging geometry, which are not accounted for in the semiempirical models. Comparison to experimental data is good for certain fluids. In other cases, the modeling suggests that effects other than fluid rheology may also have affected flow, such as adsorption or filtration. © 2004 American Institute of Chemical Engineers AIChE J, 50: 3034–3048, 2004
Urquhart and probability: The transition from librarianship to library and information science
Authors: Bensman Stephen J.
Published: November 2004

In this article, I analyze the role of Donald J. Urquhart in the creation of modern library and information science. Urquhart was one of the chief architects of information science in Britain and founder of the National Lending Library for Science and Technology (NLL), which evolved into the present‐day British Library Document Supply Centre (BLDSC). In particular, I focus on the part played by Urquhart in the development of that branch of information science termed bibliometrics, the application of mathematical and statistical techniques to information phenomena, pursuing both historical and practical aims. The article is intended not only to trace the history of the probability distributions applicable to library use and other facets of human knowledge but also to demonstrate how these distributions can be used in the evaluation and management of scientific journal collections. For these purposes, the paper is divided into three parts of equal importance. The first part is statistical and establishes the theoretical framework, within which Urquhart's work is considered. It traces the historical development of the applicable probability distributions, discussing their origins on the European continent and how Continental principles became incorporated in the biometric statistics that arose in Britain as a result of the Darwinian revolution. This part analyzes the binomial and Poisson processes, laying out the reasons why the Poisson process is more suitable for modeling information phenomena. In doing so, it describes key distributions arising from these processes as well as the various tests for these distributions, citing the literature that shows how to conduct these tests. Throughout the discussion, the relationship of these distributions to library use and the laws of information science is emphasized. The second part of the article analyzes the pioneering role of Urquhart as a conduit for the entry of these probability distributions into librarianship, converting it into library and information science. He was the first librarian to apply probability to library use, utilizing it not only to establish and manage the scientific journal collections of the NLL but also to evolve his Law of Supralibrary Use. Urquhart's work is portrayed within the context of a general trend to adopt probabilistic methods for analytical purposes, and a major premise of this article is that his law and the probabilistic breakthrough, on which it was based, were most likely in Britain, which was one of the few countries not only to develop but also maintain the necessary scientific preconditions. The third—and concluding section—discusses how Urquhart's Law forces a probabilistic reconceptualization of the functioning of the scientific journal system as well as the law's practical implications for journal sales, collection evaluation and management, resource sharing, and the transition from the paper to the electronic format.
Polycomb homologs are involved in teratogenicity of valproic acid in mice
Authors: Okada Akinobu , Aoki Yoshinobu , Kushima Kiyoshi , Kurihara Hiroshi , Bialer Meir , Fujiwara Michio
Published: November 2004

BACKGROUND

Valproic acid (VPA) is widely used to treat epilepsy and bipolar disorder and is also a potent teratogen, but its teratogenic mechanisms are unknown. We have attempted to describe a fundamental role of the Polycomb group (Pc‐G) in VPA‐induced transformations of the axial skeleton.

METHODS

Pregnant NMRI mice were given a single subcutaneous injection of vehicle or VPA (800 mg/kg) on gestation day (GD) 8. The expression of genes encoding Polycomb and trithorax groups was measured by quantitative real‐time RT‐PCR using total RNA isolated from the embryos exposed to vehicle or VPA for 1, 3, and 6 hr. In addition, the use of two less teratogenic antiepileptic chemicals valpromide (VPD) and valnoctamide (VCD) provide reliable evidence to support the relationship between VPA teratogenicity and the Polycomb group.

RESULTS

At a teratogenic level, VPA inhibits the expression of the Polycomb group genes, including Eed, Ezh2, Zfp144, Bmi1, Cbx2, Rnf2, and YY1 in the mouse embryos. In contrast, neither VPD nor VCD have significant effects on the expression of those genes affected by VPA. The trithorax group (trx‐G) gene MLL, which is known to be required to maintain homeobox gene expression such as the Polycomb gene, is not affected by a teratogenic dose of VPA.

CONCLUSIONS

We propose that, during embryonic development, VPA may affect the gene silencing pathway mediated by the Polycomb group complex. The epigenetic mechanism of VPA teratogenicity on anteroposterior patterning is suspected. Birth Defects Research (Part A), 2004. © 2004 Wiley‐Liss, Inc.
Hungarian cohort‐controlled trial of periconceptional multivitamin supplementation shows a reduction in certain congenital abnormalities
Authors: Czeizel Andrew E. , Dobó Márta , Vargha Péter
Published: November 2004

BACKGROUND

The 1984–1991 Hungarian randomized controlled trial (RCT) of periconceptional multivitamin supplementation containing folic acid (0.8 mg) showed a significant reduction in the first occurrence of neural tube defects (NTDs), and of urinary tract and cardiovascular abnormalities, but no reduction in orofacial clefts. A controlled cohort trial was designed to confirm or deny these results.

METHODS

Supplemented women were recruited from the Hungarian Periconceptional Service using the same multivitamin as the Hungarian RCT. Unsupplemented pregnant women were recruited in the standard regional antenatal care clinics and were matched to each supplemented pregnant woman on the basis of age, socioeconomic status, place of residence, and year of pregnancy.

RESULTS

A total of 3056 informative offspring were evaluated in each cohort. The occurrence of congenital cardiovascular malformations (31 vs. 50) was reduced (odds ratio [OR], 0.60; 95% confidence interval [CI], 0.38–0.96) in the supplemented cohort, accounted for mainly by ventricular septal defects (5 vs. 19; OR, 0.26; 95% CI, 0.09–0.72). There was no significant difference (14 vs. 19) in the occurrence of urinary tract defects between the two cohorts, but stenosis/atresia of pelvicureteric junction (2 vs. 13) showed a significant reduction (OR, 0.19; 95% CI, 0.04–0.86). The protective effect of the folic acid–containing multivitamin for NTDs (one offspring in the supplemented vs. nine in the unsupplemented cohort) was confirmed (OR, 0.11; 95% CI, 0.01–0.91). There was, however, no protective effect on orofacial clefts or on multiple congenital abnormalities.

CONCLUSIONS

The results of this cohort‐controlled trial support the findings of the previous Hungarian RCT. The primary prevention of some major structural birth defects by multivitamins containing folic acid or by folic acid has great public health importance. Birth Defects Research (Part A), 2004. © 2004 Wiley‐Liss, Inc.
Toward an aggregated understanding of enzymatic hydrolysis of cellulose: Noncomplexed cellulase systems
Authors: Zhang Yi‐Heng Percival , Lynd Lee R.
Published: November 2004

Information pertaining to enzymatic hydrolysis of cellulose by noncomplexed cellulase enzyme systems is reviewed with a particular emphasis on development of aggregated understanding incorporating substrate features in addition to concentration and multiple cellulase components. Topics considered include properties of cellulose, adsorption, cellulose hydrolysis, and quantitative models. A classification scheme is proposed for quantitative models for enzymatic hydrolysis of cellulose based on the number of solubilizing activities and substrate state variables included. We suggest that it is timely to revisit and reinvigorate functional modeling of cellulose hydrolysis, and that this would be highly beneficial if not necessary in order to bring to bear the large volume of information available on cellulase components on the primary applications that motivate interest in the subject. © 2004 Wiley Periodicals, Inc.
Protonation Behaviour of Chiral Tetradentate Polypyridines Derived from α‐Pinene
Authors: Düggeli Mathias , Christen Tobias , von Zelewsky Alexander
Published: November 2004

Detailed protonation experiments of the [5,6]‐pinenebipyridine molecule and the unsubstituted [4,5]‐ and [5,6]‐CHIRAGEN[0] ligands in various solvents indicate a variety of structures of the protonated species. UV‐visible and NMR measurements (including 15N chemical shifts) show the transition from trans to cis conformation of [5,6]‐pinenebipyridine upon protonation. The [4,5]‐CHIRAGEN[0] ligand, in which the protonation sites of the nitrogen atom donors are at opposite sides of the molecule, behave essentially like two independent bipyridine moieties; this behaviour was monitored by UV‐visible, CD and NMR spectroscopy (including 15N data). In the case of the [5,6]‐CHIRAGEN[0], a pocket of donor atoms provides a chiral environment for two protons per ligand.
Low‐Melting, Low‐Viscous, Hydrophobic Ionic Liquids: 1‐Alkyl(Alkyl Ether)‐3‐methylimidazolium Perfluoroalkyltrifluoroborate
Authors: Zhou Zhi‐Bin , Matsumoto Hajime , Tatsumi Kuniaki
Published: November 2004

A series of twenty two hydrophobic ionic liquids, 1‐alkyl(alkyl ether)‐3‐methylimidazolium ([Cmmim]+ or [CmOnmim]+; where Cm is 1‐alkyl, Cm=nCmH2m+1, m=1–4 and 6; CmOn is 1‐alkyl ether, C2O1=CH3OCH2, C3O1=CH3OCH2CH2, and C5O2=CH3(OCH2CH2)2) perfluoroalkyltrifluoroborate ([RFBF3]−, RF=CF3, C2F5, nC3F7, nC4F9), have been prepared and characterized. Some of the important physicochemical properties of these salts including melting point, glass transition, viscosity, density, ionic conductivity, thermal and electrochemical stability, have been determined and were compared with those of the reported [BF4]−‐based ones. The influence of the structure variation in the imidazolium cation and the perfluoroalkyltrifluoroborate ([RFBF3]−) anion on the above physicochemical properties was discussed. The key features of these new salts are their low melting points (−42 to 35 °C) or extremely low glass transition (between −87 and −117 °C) without melting, and considerably low viscosities (26–77 cP at 25 °C).
In Quest of Factors That Control the Enantioselective Catalytic Markovnikov Hydroboration/Oxidation of Vinylarenes
Authors: Segarra Anna M. , Daura‐Oller Elias , Claver Carmen , Poblet Josep M. , Bo Carles , Fernández Elena
Published: November 2004

This study attempts to rationalise the unpredictable performance of transition metal catalysed asymmetric hydroboration of vinylarenes on varying the precursor of the catalyst from cationic to neutral species, [M(cod)(L–L)]BF4, [M(μ‐Cl)(cod)]2/(L–L), the metal (M=Rh and Ir), and the hydroborating reagent (catecholborane, pinacolborane). The approaches are based on the agreement between experimental data provided by (R)‐Binap and (R)‐Quinap modified catalytic systems and computational data evidenced by DFT calculations and QM/MM strategies. Unprecedentedly high enantiomeric excesses in the hydroboration/oxidation of vinylarenes with both electron‐withdrawing substituents ((R)‐(+)‐1‐p‐F‐phenylethanol, ee up to 92 %) and electron‐releasing substituents ((R)‐(+)‐1‐p‐MeO‐phenylethanol, ee up to 98 %), can be attributed to a rhodium halide key intermediate.
First Detection of a Selenenyl Fluoride ArSeF by NMR Spectroscopy: The Nature of Ar2Se2/XeF2 and ArSeSiMe3/XeF2 Reagents
Authors: Poleschner Helmut , Seppelt Konrad
Published: November 2004

Arylselenenyl fluorides ArSeF are obtained from diselenides Ar2Se2 or arylselenotrimethylsilanes ArSeSiMe3, and XeF2. They are detected by low‐temperature 19F and 77Se NMR spectroscopy. Substitution in the ortho position of the aromatic ring to provide electronic or steric protection is a requirement for their formation. ArSeF compounds decompose according to 3 ArSeF→[ArSeSeF2Ar]+ArSeF→ArSeF3+Ar2Se2. Reaction energies for this disproportionation as well as that of the sulfur and tellurium homologues have been calculated with MP2, CCSD(T,) and B3 LYP methods. They were found to be increasingly exothermic in the sequence S<Se<Te. For selected SeC and SeF compounds the 77Se and 19F chemical shifts have been calculated by GIAO‐MP2 and GIAO‐B3 LYP methods and are in good agreement with experimental values.
Discrepancy between the Spin Distribution and the Magnetic Ground State for a Triaminoxyl Substituted Triphenylphosphine Oxide Derivative
Authors: Borobia Oscar Benedi , Guionneau Philippe , Heise Henrike , Köhler Frank H. , Ducasse Laurent , Vidal‐Gancedo Jose , Veciana Jaume , Golhen Stéphane , Ouahab Lahcène , Sutter Jean‐Pascal
Published: November 2004

The magnetic interaction and spin transfer via phosphorus have been investigated for the tri‐tert‐butylaminoxyl para‐substituted triphenylphosphine oxide. For this radical unit, the conjugation existing between the π* orbital of the NO group and the phenyl π orbitals leads to an efficient delocalization of the spin from the radical to the neighboring aromatic ring. This has been confirmed by using fluid solution high‐resolution EPR and solid state MAS NMR spectroscopy. The spin densities located on the atoms of the molecule could be probed since 1H, 13C, 14N, and 31P are nuclei active in NMR and EPR, and lead to a precise spin distribution map for the triradical. The experimental investigations were completed by a DFT computational study. These techniques established in particular that spin density is located at the phosphorus (ρ=−15×10−3 au), that its sign is in line with the sign alternation principle and that its magnitude is in the order of that found on the aromatic C atoms of the molecule. Surprisingly, whereas the spin distribution scheme supports ferromagnetic interactions among the radical units, the magnetic behavior found for this molecule revealed a low‐spin ground state characterized by an intramolecular exchange parameter of J=−7.55 cm−1 as revealed by solid state susceptibility studies and low temperature EPR. The X‐ray crystal structures solved at 293 and 30 K show the occurrence of a crystallographic transition resulting in an ordering of the molecular units at low temperature.
Novel Carbohydrate‐Appended Metal Complexes for Potential Use in Molecular Imaging
Authors: Storr Tim , Obata Makoto , Fisher Cara L. , Bayly Simon R. , Green David E. , Brudziñska Izabela , Mikata Yuji , Patrick Brian O. , Adam Michael J. , Yano Shigenobu , Orvig Chris
Published: November 2004

Seven discrete sugar‐pendant diamines were complexed to the {M(CO)3}+ (99mTc/Re) core: 1,3‐diamino‐2‐propyl β‐D‐glucopyranoside (L1), 1,3‐diamino‐2‐propyl β‐D‐xylopyranoside (L2), 1,3‐diamino‐2‐propyl α‐D‐mannopyranoside (L3), 1,3‐diamino‐2‐propyl α‐D‐galactopyranoside (L4), 1,3‐diamino‐2‐propyl β‐D‐galactopyranoside (L5), 1,3‐diamino‐2‐propyl β‐(α‐D‐glucopyranosyl‐(1,4)‐D‐glucopyranoside) (L6), and bis(aminomethyl)bis[(β‐D‐glucopyranosyloxy)methyl]methane (L7). The Re complexes [Re(L1–L7)(Br)(CO)3] were characterized by 1H and 13C 1D/2D NMR spectroscopy which confirmed the pendant nature of the carbohydrate moieties in solution. Additional characterization was provided by IR spectroscopy, elemental analysis, and mass spectrometry. Two analogues, [Re(L2)(CO)3Br] and [Re(L3)(CO)3Br], were characterized in the solid state by X‐ray crystallography and represent the first reported structures of Re organometallic carbohydrate compounds. Conductivity measurements in H2O established that the complexes exist as [Re(L1–L7)(H2O)(CO)3]Br in aqueous conditions. Radiolabelling of L1–L7 with [99mTc(H2O)3(CO)3]+ afforded in high yield compounds of identical character to the Re analogues. The radiolabelled compounds were determined to exhibit high in vitro stability towards ligand exchange in the presence of an excess of either cysteine or histidine over a 24 h period.
Using Diffusion NMR To Characterize Guanosine Self‐Association: Insights into Structure and Mechanism
Authors: Kaucher Mark S. , Lam Yui‐Fai , Pieraccini Silvia , Gottarelli Giovanni , Davis Jeffery T.
Published: November 2004

This paper presents results from a series of pulsed field gradient (PFG) NMR studies on lipophilic guanosine nucleosides that undergo cation‐templated assembly in organic solvents. The use of PFG‐NMR to measure diffusion coefficients for the different aggregates allowed us to observe the influences of cation, solvent and anion on the self‐assembly process. Three case studies are presented. In the first study, diffusion NMR confirmed formation of a hexadecameric G‐quadruplex [G 1]16⋅4 K+⋅4 pic− in CD3CN. Furthermore, hexadecamer formation from 5′‐TBDMS‐2′,3′‐isopropylidene G 1 and K+ picrate was shown to be a cooperative process in CD3CN. In the second study, diffusion NMR studies on 5′‐(3,5‐bis(methoxy)benzoyl)‐2′,3′‐isopropylidene G 4 showed that hierarchical self‐association of G8‐octamers is controlled by the K+ cation. Evidence for formation of both discrete G8‐octamers and G16‐hexadecamers in CD2Cl2 was obtained. The position of this octamer–hexadecamer equilibrium was shown to depend on the K+ concentration. In the third case, diffusion NMR was used to determine the size of a guanosine self‐assembly where NMR signal integration was ambiguous. Thus, both diffusion NMR and ESI‐MS show that 5′‐O‐acetyl‐2′,3′‐O‐isopropylidene G 7 and Na+ picrate form a doubly charged octamer [G 7]8⋅2 Na+⋅2 pic− 9 in CD2Cl2. The anion's role in stabilizing this particular complex is discussed. In all three cases the information gained from the diffusion NMR technique enabled us to better understand the self‐assembly processes, especially regarding the roles of cation, anion and solvent.
Synthesis, Characterization, and Properties of Subporphyrazines: A New Class of Nonplanar, Aromatic Macrocycles with Absorption in the Green Region
Authors: Rodríguez‐Morgade M. Salomé , Esperanza Sagrario , Torres Tomás , Barberá Joaquín
Published: November 2004

Novel subphthalocyanine analogues that display strong absorption in the green region have been synthesized by using a boron template cyclotrimerization of maleonitrile derivatives. The spectroscopic properties of these macrocycles indicate that, like subphthalocyanines, they have 14 π electrons and are aromatic compounds with a conical shape. The removal of the three fused benzene rings from the subphthalocyanine skeleton produces a 75–80 nm blue shift of the Q‐band and a slight lowering of the absorption coefficients for this band. In addition, the reduction of the π system from 18 to 14 electrons that accompanies progression from porphyrazines to subporphyrazines causes a hypsochromic shift of the Q‐band of around 100 nm. Subporphyrazines that are peripherally functionalized with six thioether chains, and in which the sulfur atoms are attached directly to the pyrrole moieties, exhibit optical features that may be explained in terms of the extension of π conjugation over the six thiolene groups, as well as strong π donation from the sulfur lone pairs to the macrocycle. These two effects are quantitatively and qualitatively very similar to those observed for porphyrazines that possess the same type of substitution. In addition, the mesomorphic behavior at low temperatures of a macrocycle that is substituted with six thiododecyl chains was demonstrated by using differential scanning calorimetry and optical polarising microscopy.
Long‐term results of high‐dose rate intracavitary brachytherapy for squamous cell carcinoma of the uterine cervix
Authors: Nakano Takashi , Kato Shingo , Ohno Tatsuya , Tsujii Hirohiko , Sato Shinichiro , Fukuhisa Kenjiro , Arai Tatsuo
Published: November 2004

BACKGROUND

The authors performed a long‐term follow‐up study to evaluate the efficacy and late toxicity of high‐dose rate intracavitary brachytherapy (HDR‐ICBT) for cervical carcinoma.

METHODS

From 1968 to 1986, 1148 patients with Stage IB to IVB squamous cell carcinoma of the cervix (staging was performed according to the International Federation of Gynecology and Obstetrics) were treated with a combination of external beam radiotherapy (EBRT) and HDR‐ICBT. For patients with early‐stage disease, 20 gray (Gy) of EBRT was delivered to the whole pelvis, followed by 24 Gy/4 fractions of HDR‐ICBT and 30 Gy of central‐shielding EBRT. For patients with advanced‐stage disease, 20–40 Gy of whole pelvic EBRT was administered, followed by 24 Gy/4 fractions of ICBT and 30–10 Gy of central‐shielding EBRT. The overall treatment time was approximately 6 weeks. Among survivors, the follow‐up rate was 98% and the median follow‐up duration was 22 years.

RESULTS

The 10‐year pelvic tumor control rates were 93% for patients with Stage IB disease, 82% for patients with Stage II disease, and 75% for patients with Stage III disease. The 10‐year overall and cause‐specific survival rates were 74% and 89% for patients with Stage IB disease, 52% and 74% for patients with Stage II disease, and 42% and 59% for patients with Stage III disease, respectively. The 10‐year actuarial rates of major complications were 4.4% in the rectosigmoid colon, 0.9% in the bladder, and 3.3% in the small intestines.

CONCLUSIONS

The results of the current study suggest that the combination of EBRT and HDR‐ICBT according to the authors' protocol provided outcomes that were comparable to those of the conventional low‐dose rate brachytherapy with acceptable rates of late complications in the treatment of cervical carcinoma. Cancer 2005. © 2004 American Cancer Society.
Assessing the feasibility of single lifetime PAP smear evaluation between 41–50 years of age as strategy for cervical cancer control in developing countries from our 32 years of experience of hospital‐based routine cytological screening
Authors: Misra Jata S. , Gupta Hem P. , Das Vinita
Published: November 2004

In view of the huge expenditure involved in mass cytological screening as well as lack of cytology manpower in the developing countries, single lifetime screening at 45 yr of age has been suggested as feasible strategy for control of cervical cancer. The present study is aimed at testing this hypothesis in a broader prospective, accommodating women between 41 and 50 yr of age from the data derived from the ongoing long‐term hospital‐based routine cervicovaginal cytology at Queen Mary's Hospital, Lucknow, India. The cervical smears of 31,032 women have been evaluated cytologically during a span of 32 yr (April 1971–March 2003) for early detection of carcinoma cervix and sexually transmitted diseases (STDs). The incidence of squamous intraepithelial lesions (SIL) was found to be 6.1% while frank malignancy was seen in 0.5% of cases. The following observations were made from the accumulated cytological data: (a) approximately 30% of the total cancer cases was in the age group of 41–50 yr; (b) the maximum number of SIL cases was detected in women between 41 and 50 yr of age (35% of the total SIL cases), and adequate management of these SIL cases would prevent cancer cases from occurring in later years, thus minimizing the maximum incidence of 1.3% observed in women beyond 50 yr of age; (c) the incidence of human papillomavirus (HPV) infection also was found quite high in women between 41 and 50 yr old, the adequate management of which would prevent onset/progression of any premalignant changes in the cervix.

Our experience of 32 yr of cytological screening substantiates the hypothesis of single lifetime screening between 41 and 50 yr of age as an effective strategy for control of carcinoma cervix in developing countries like ours. Diagn. Cytopathol. 2004;31:376–379. © 2004 Wiley‐Liss, Inc.
Design and evaluation of an interface‐based naming system for supporting service synthesis in a ubiquitous computing environment
Authors: Minami Masateru , Morikawa Hiroyuki , Aoyama Tomonori
Published: November 2004

This paper considers the ubiquitous environment, in which a tremendous number of objects, such as physical devices, multimedia contents, and software components, exist everywhere. In order to provide and utilize various services transparently in such an environment, there must be a service synthesis technique that can dynamically construct services by mutually connecting objects. The realization of service synthesis requires a position‐independent naming service which can securely and transparently call from the network the functions (functional objects) that act as the service component. The authors designed an interface‐based naming service which can perform transparent calling of functional objects on the basis of interface information on the objects. The interface‐based naming service not only can call functional objects efficiently from the network, but also can provide several useful features of service synthesis support: when two functional objects are interconnected, the required supplementary functional object is automatically determined, and when a function cannot be found, that function is realized equivalently by using multiple functional objects. This paper describes the architecture of the interface‐based naming service, together with its algorithm. The approach is evaluated by simulation and it is shown that the interface‐based naming service is a useful system in a ubiquitous environment with an increased number of objects and an enlarged network scale. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 88(3): 63–75, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10177
A synchronization method deselecting candidate positions with chip level detection for optical CDMA
Authors: Iwata Ayako , Kamakura Koji , Sasase Iwao
Published: November 2004

In order to reduce the number of preamble bits required for synchronization at correct positions, a method of synchronization by deselecting the candidate positions for synchronization is proposed. As decision methods for each preamble bit, a method using the threshold detection and a method using chip level detection are discussed. Both methods make use of the fact that the preamble bit is the bit “1”: any synchronization position judged not to be a “1” bit even once is deselected as a candidate. In this way, the only position eventually remaining without being deselected is judged to be the synchronization position. As a result, it is possible to carry out synchronization with fewer preamble bits than the conventional method in which bit decision is based on the logarithmic likelihood ratio of the continuously transmitted preamble bits. A theoretical analysis is made under the assumption that the output of the photodetector follows a Poisson distribution. It is found that the proposed method can perform synchronization within a shorter time than the conventional synchronization method. Further, in the method using chip level detection, it is shown that synchronization is achieved in a shorter time even if the bit decision threshold is fixed. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 88(3): 21–32, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20160
Analysis of mutation spectra in UVB‐exposed mouse skin epidermis and dermis: Frequent occurrence of C→T transition at methylated CpG‐associated dipyrimidine sites
Authors: Ikehata Hironobu , Masuda Toshinari , Sakata Hiroyuki , Ono Tetsuya
Published: November 2004

We recently reported the kinetics of mutation induction by UVB in the skin epidermis and dermis of transgenic Muta™ mice [Ikehata and Ono, Mutat Res 508:41–47, 2002]. In the present study we determined the complete DNA sequence of the lacZ transgene in 208 mutants isolated from the dermis and epidermis of UVB‐irradiated and control mice. The resulting mutation patterns for the dermis and epidermis were similar, although two CC→TT tandem substitutions, one of the signature mutations for UV insult, were detected only among the UVB‐induced epidermal mutants. The spectra of the UVB‐induced and control mutations were both dominated by C→T transitions (83% and 62%); however, the C→T transitions from irradiated mice occurred almost exclusively in dipyrimidine sites, while those from control mice preferred CpG sites. Thus, the mutation spectrum detected for the irradiated skin tissues was different from the background spectrum and UV‐specific, confirming the utility of the transgenic system for UVB‐induced mutation studies in vivo. An analysis of the bases adjacent to the mutated cytosines from irradiated mice revealed that the dipyrimidine sites preferred for UVB‐induced mutation were 5′‐TC‐3′ > 5′‐CC‐3′ > 5′‐CT‐3′. Among mutants from irradiated mice, C→T transitions were recovered frequently at dipyrimidine sites associated with CpG. We showed that CpG sites in the lacZ transgene of Muta™ mice were heavily methylated in both the epidermis and dermis. Thus, CpG methylation could contribute to the UVB‐induced recurrent or hotspot mutations in the mammalian genome. Environ. Mol. Mutagen. 41:280–292, 2003. © 2003 Wiley‐Liss, Inc.
Activation of HLXB9 by juxtaposition with MYB via formation of t(6;7)(q23;q36) in an AML‐M4 cell line (GDM‐1)
Authors: Nagel Stefan , Kaufmann Maren , Scherr Michaela , Drexler Hans G. , MacLeod Roderick A. F.
Published: November 2004

Mutation or dysregulation of related homeobox genes occurs in leukemia. Using RT‐PCR, we screened members of the EHG family of homeobox genes, comprising EN1 (at 2q14), GBX2 (at 2q36), and EN2, GBX1, and HLXB9 (at 7q36), for dysregulation in acute myeloid leukemia (AML) cell lines indicated by chromosomal breakpoints at these sites. Only one EHG‐family gene was expressed, HLXB9, in cell line GDM‐1 (AML‐M4). Karyotypic analysis of GDM‐1 revealed a unique t(6;7)(q23;q35), also present in the patient. Fluorescence in situ hybridization analysis showed chromosomal breakpoints close to the region upstream of HLXB9, at 7q36, a region rearranged in certain AML patients, and at 6q23 upstream of MYB, a gene activated in leukemia. Detailed expression analysis suggested ectopic activation of HLXB9 occurred via juxtaposition with regions upstream of MYB, which was highly expressed in GDM‐1. Our data identified a cell line model for a novel leukemic translocation involving MYB with HLXB9, further implicating HLXB9 in leukemogenesis. © 2004 Wiley‐Liss, Inc.