bluuebunny/crossref_metadata_2025 huggingface dataset:
Carbene Formation in the Photochemistry of Cyclic Ketones
Authors: Roberts S. M.
Published: April 2004

For Abstract see ChemInform Abstract in Full Text.
Photochemical Decarbonylation of Ketones: Recent Advances and Reactions in Crystalline Solids
Authors: Garcia‐Garibay Miguel A. , Campos Luis M.
Published: April 2004

For Abstract see ChemInform Abstract in Full Text.
The Photostimulated SRN1 Process: Reaction of Haloarenes with Carbanions
Authors: Rossi Roberto A. , Penenory Alicia B.
Published: April 2004

For Abstract see ChemInform Abstract in Full Text.
The Photochemistry of Substituted Benzenes: Phototranspositions and the Photoadditions of Alcohols
Authors: Pincock James A.
Published: April 2004

For Abstract see ChemInform Abstract in Full Text.
Photo‐Fries Reaction and Related Processes
Authors: Miranda Miguel Angel , Galindo Francisco
Published: April 2004

For Abstract see ChemInform Abstract in Full Text.
Intra‐ and Intermolecular Cycloadditions of Benzene Derivatives
Authors: Gilbert Andrew
Published: April 2004

For Abstract see ChemInform Abstract in Full Text.
The Photochemical Nucleophile—Olefin Combination, Aromatic Substitution (Photo‐NOCAS) Reaction
Authors: Mangion Dino , Arnold Donald R.
Published: April 2004

For Abstract see ChemInform Abstract in Full Text.
The Dimerization of Cinnamic Acid Derivatives
Authors: Bassani Dario M.
Published: April 2004

For Abstract see ChemInform Abstract in Full Text.
Photochemical Isomerization of Cycloalkenes
Authors: Mori Tadashi , Inoue Yoshihisa
Published: April 2004

For Abstract see ChemInform Abstract in Full Text.
Photoreactions of Alkenes in Protic Media
Authors: Kropp Paul J.
Published: April 2004

For Abstract see ChemInform Abstract in Full Text.
The Dynamic Status Quo of Polyhedral Silsesquioxane Coordination Chemistry
Authors: Hanssen Rob W. J. M. , van Santen Rutger A. , Abbenhuis Hendrikus C. L.
Published: April 2004

For Abstract see ChemInform Abstract in Full Text.
Thermolysis of Organic Peroxides in Solution
Authors: Antonovskii V. L. , Khursan S. L.
Published: April 2004

For Abstract see ChemInform Abstract in Full Text.
RNA Crystallization
Authors: Golden Barbara L. , Kundrot Craig E.
Published: April 2004

For Abstract see ChemInform Abstract in Full Text.
Dinitrogen Coordination Chemistry: The Biomimetic Borderlands
Authors: MacKay Bruce A. , Fryzuk Michael D.
Published: April 2004

For Abstract see ChemInform Abstract in Full Text.
Membrane Bioreactors: An Excellent Option for Wastewater Treatment
Authors: Balomajumder C. , Sagar V. Vidya
Published: April 2004

For Abstract see ChemInform Abstract in Full Text.
Effective Molarities in Supramolecular Catalysis of Two‐Substrate Reactions
Authors: Cacciapaglia Roberta , Di Stefano Stefano , Mandolini Luigi
Published: April 2004

For Abstract see ChemInform Abstract in Full Text.
Principles of Mononucleating and Binucleating Ligand Design
Authors: Gavrilova Anna L. , Bosnich Brice
Published: April 2004

For Abstract see ChemInform Abstract in Full Text.
Theoretical Insights in Enzyme Catalysis
Authors: Marti Sergio , Roca Maite , Andres Juan , Moliner Vicent , Silla Estanislao , Tunon Inaki , Bertran Juan
Published: April 2004

For Abstract see ChemInform Abstract in Full Text.
Density Functional Theory and Its Application to Nuclear Magnetic Resonance Shielding Constants
Authors: Wilson Philip J.
Published: April 2004

For Abstract see ChemInform Abstract in Full Text.
In situ Spectroscopy of Catalytic Solid—Liquid Interfaces and Chiral Surfaces
Authors: Buergi Thomas
Published: April 2004

For Abstract see ChemInform Abstract in Full Text.
Floating shield current suppression trap
Authors: Seeber D.A. , Jevtic J. , Menon A.
Published: April 2004

Shield currents or common mode currents affect coil tuning, coil‐to‐coil coupling in phased array coils, image inhomogeneity, and most importantly can cause serious patient burns. Traditionally in MRI, shield currents are reduced by cable traps; they consist of a wound coaxial cable inductor tuned to the desired resonance frequency by a capacitor between end turns of the coaxial cable ground shield. This method increases losses and effects the overall phase distance between the coil and the preamplifiers. We present a cable trap that does not connect or solder to the cable and is completely splitable, allowing easy fitting over any cable without affecting any coil parameters (tuning or phase length). Multiple cables can be placed inside the shield current trap to simultaneously attenuate the shield currents from up to eight cables, as currently designed. The shield current trap reduces shield currents at 64 MHz by ∼30 dB. © 2004 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 21B: 26–31, 2004.
Pulse programmer for electron paramagnetic resonance spectroscopy
Authors: Gromov I. , Glass B. , Keller J. , Shane J. , Forrer J. , Tschaggelar R. , Schweiger A.
Published: April 2004

The design of a new pulse programmer is presented. It is based on an application‐specific integrated circuit (ASIC) and designed to fulfill the requirements of pulse electron paramagnetic resonance (EPR). The pulse EPR ASIC provides a high time resolution (2 ns) and a high channel density (8 channels per chip). The pulse sequences are controlled by a digital signal processor (DSP). The sequence processing is solved in a general way: the pulse program, written in a high‐level Pulse Programming Language (PPL), is interpreted by the DSP, which then calculates a bit image, loads it to the ASICs, and controls the sequence flow. The approach allows any sequence to be easily programmed, and the pulse EPR experiments can be carried out in real time on a repetition rate of up to 2 kHz. The new pulse programmer provides the same or even a higher time resolution and channel density than general‐purpose commercial programmers, which are in use in home‐built EPR spectrometers. At the same time, the device has a shorter reprogramming time than these programmers and can compete, in particular for 2D experiments, with the existing pulse EPR‐oriented commercial systems. In comparison with commercial analogs the software provides the users with a more flexible control over the sequence programming. The capacity of the programmer for work is demonstrated by three‐pulse ESEEM and HYSCORE experiments. © 2004 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 21B: 1–10, 2004.
Outcome after local recurrence of osteosarcoma
Authors: Rodriguez‐Galindo Carlos , Shah Nirali , McCarville M. Beth , Billups Catherine A. , Neel Michael N. , Rao Bhaskar N. , Daw Najat C.
Published: April 2004

BACKGROUND

Despite improvements in therapy for osteosarcoma, approximately 4–10% of patients experience a local recurrence and have a poor prognosis.

METHODS

The authors analyzed prognostic factors for survival in 26 patients with a local recurrence of osteosarcoma who were treated between 1970 and 2000.

RESULTS

The initial surgical procedure was amputation in 20 patients (76.9%) and limb salvage in 6 patients (23.1%). The median time from the diagnosis of osteosarcoma to local recurrence was 1.2 years (range, 1.2 months–6.1 years). Eleven patients (42.3%) developed an isolated local recurrence and 15 patients (57.7%) developed local and distant recurrence. The 5‐year estimate of postrecurrence survival (PRS) (± 1 standard error) for the 26 patients was 19.2% ± 7.7%. Recurrence ≥ 2 years from the time of diagnosis was found to predict a better outcome (5‐year PRS of 50.0% ± 20.4%) compared with earlier recurrence (10.0% ± 5.5%) (P = 0.037). Patients with negative margins after initial surgery were found to have improved survival (5‐year PRS of 33.3% ± 13.6%) compared with patients with positive margins (7.1% ± 4.9%) (P = 0.015). Patients who underwent complete surgical resection at the time of recurrence were found to have a better PRS (5‐year PRS of 41.7% ± 14.2%) compared with patients who did not undergo surgery (0% ± 0%) (P < 0.001).

CONCLUSIONS

The prognosis for patients after local recurrence of osteosarcoma is poor. Complete surgical resection at the time of recurrence is essential for survival. Positive margins at the time of initial surgical resection and early recurrence appear to be poor prognostic factors. Cancer 2004. © 2004 American Cancer Society.
Repeat breast‐conserving surgery for in‐breast local breast carcinoma recurrence
Authors: Kuerer Henry M. , Arthur Douglas W. , Haffty Bruce G.
Published: April 2004

Mastectomy is the current standard of care for in‐breast local recurrence of breast carcinoma. The objective of the current study was to critically review the rationale for and the theoretic and actual risks and benefits of repeat breast‐conserving surgery followed by partial breast irradiation (PBI) for in‐breast local recurrence of breast carcinoma. The main outcomes of interest were local control and survival after in‐breast local recurrence and side effects, complications, and cosmesis after reirradiation of the breast. The risk of local recurrence was not found to be eliminated with mastectomy; approximately 2–32% of patients treated with mastectomy develop a chest wall recurrence. The interpretation of local control rates in evaluating repeat breast‐conserving surgery studies is difficult because of the lack of information regarding preoperative diagnostic mammography to rule out concurrent multicentric disease and microscopic margin status after surgery. Rates of subsequent local recurrence in these studies appeared to be between 19–50%, similar to reported rates of in‐breast local recurrence in patients with a first diagnosis of breast carcinoma who were treated with conservative surgery without irradiation. Early follow‐up studies of breast reirradiation suggest that catheter‐based interstitial brachytherapy and standard external beam radiation therapy can be delivered to the breast more than once without significant side effects in most patients and with acceptable cosmesis in some patients. Mastectomy may not be necessary in all patients with an in‐breast local recurrence of breast carcinoma. Recent advances in conformal radiation delivery and single‐center published reports concerning repeat breast‐conserving therapy support well designed prospective trials to formally test this hypothesis. Cancer 2004. © 2004 American Cancer Society.
Expression of MOR1C‐like μ‐opioid receptor mRNA in rats
Authors: Schnell Stephen A. , Wessendorf Martin W.
Published: April 2004

The reverse transcriptase‐polymerase chain reaction (RT‐PCR) was used to clone a cDNA fragment of a putative G‐protein–coupled receptor from rat brain total RNA. Nucleotide sequencing of this cDNA fragment showed it to be homologous to that of the μ‐opioid receptor splice variant MOR1C from mice. We used the cDNA to make an RNA probe for a ribonuclease protection assay (RPA). The results from the RPA showed a protected fragment of the size expected for MOR1C mRNA, as well as other RNase‐protected fragments that may indicate the existence of other MOR1 transcripts. We then used the RNA probe for in situ hybridization (ISH) experiments. We detected strong autoradiographic labeling over much of the rat telencephalon, diencephalon, mesencephalon, cerebellum, spinal cord, and dorsal root ganglia. These findings suggest that MOR1C, and possibly other MOR1 splice variants, are important components of the system by which the actions of opioids are transduced. J. Comp. Neurol. 473:213–232, 2004. © 2004 Wiley‐Liss, Inc.
Local Structure of Amorphous Ice as Revealed by O K‐Edge EXAFS
Authors: Zubavichus Yan , Yang Yongjie , Zharnikov Michael , Fuchs Oliver , Schmidt Thomas , Heske Clemens , Umbach Eberhard , Tzvetkov George , Netzer Falko P. , Grunze Michael
Published: April 2004

The oxygen K‐edge extended X‐ray absorption fine structure (EXAFS) spectrum of an ice film prepared by deposition of water vapor on a substrate at 100 K was measured in the surface‐sensitive Auger yield mode. Five distinct peaks are revealed in the Fourier transform spectrum of the EXAFS data. The peaks are attributed to OH bonds (with overlapping contributions from intramolecular covalent and intermolecular hydrogen bonds) as well as to intermolecular O⋅⋅⋅O scattering paths in the distance range of 1–7 Å. The pattern of the longer O⋅⋅⋅O distances resembles that of a high‐pressure crystalline modification of ice (ice II).
Dissipative Particle Dynamics Simulations in the Grand Canonical Ensemble: Applications to Polymer Brushes
Authors: Goujon Florent , Malfreyt Patrice , Tildesley Dominic J.
Published: April 2004

We have used the dissipative particle dynamics (DPD) method in the grand canonical ensemble to study the compression of grafted polymer brushes in good solvent conditions. The force–distance profiles calculated from DPD simulations in the grand canonical ensemble are in very good agreement with the self‐consistent field (SCF) theoretical models and with experimental results for two polystyrene brush layers grafted onto mica surfaces in toluene.
Single Bubble Sonoluminescence–A Chemist's Overview
Authors: Ashokkumar Muthupandian , Grieser Franz
Published: April 2004

The phenomenon of sonoluminescence has been known for over 60 years but it is only over the last few years that a better understanding of its origins has emerged. In part the discovery of single bubble sonoluminescence, just over 10 years ago, has been a major contributor to the theoretical advances that have been made to account for the event. This Minireview is from the perspective of a physical chemist and considers the progress that has been made in understanding the role of solutes in affecting the sonoluminescence from a solution exposed to ultrasound. The physicochemical properties of solutes that are important in controlling both single bubble and multibubble sonoluminescence are discussed.
Spectroscopic and Theoretical Study of the Molecular and Electronic Structures of a Terthiophene‐Based Quinodimethane
Authors: Casado Juan , Pappenfus Ted M. , Mann Kent R. , Ortí Enrique , Viruela Pedro M. , Milián Begoña , Hernández Víctor , López Navarrete Juan T.
Published: April 2004

The UV/Vis, infrared absorption, and Raman scattering spectra of 3′,4′‐dibutyl‐5,5″‐bis(dicyanomethylene)‐5,5″‐dihydro‐2,2′:5′,2″‐terthiophene have been analyzed with the aid of density functional theory calculations. The compound exhibits a quinoid structure in its ground electronic state and presents an intramolecular charge transfer from the terthiophene moiety to the C(CN)2 groups. The molecular system therefore consists of an electron‐deficient terthiophene backbone end‐capped with electron‐rich C(CN)2 groups. The molecule is characterized by a strong absorption in the red, due to the HOMO→LUMO π–π* electronic transition of the terthiophene backbone that shifts hypsochromically on passing from the solid state to solution and with the polarity of the solvent. The analysis of the vibrational spectra confirms the structural conclusions and supports the existence of an intramolecular charge transfer. Vibrational spectra in several solvents and as a function of temperature have also been studied. Significant frequency upshifts of the vibrations involved in the π‐electron‐conjugated pathway have been noticed upon solution in polar solvents and with the lowering of the temperature. Finally, we propose a quinoid molecule as a reliable structural and electronic model for dication species in doped oligothiophenes or for bipolaron charged defects in doped polythiophene.
Structure and Dynamics of Self‐Assembled Poly(ethylene glycol) Based Coiled‐Coil Nano‐Objects
Authors: Vandermeulen Guido W. M. , Hinderberger Dariush , Xu Hui , Sheiko Sergei S. , Jeschke Gunnar , Klok Harm‐Anton
Published: April 2004

Herein we describe the structure and dynamics of self‐assembled nano‐objects generated from poly(ethylene glycol) based (PEGylated) coiled‐coil hybrid block copolymers. Electron paramagnetic resonance (EPR) experiments on spin‐labeled samples provided a strong indication for a parallel alignment of the peptide helices in at least the dimeric coiled‐coil nano‐object and indicated that the PEG chains are folded rather closely around the peptide core of the nano‐objects. The EPR results were supported by AFM studies, which revealed the presence of discrete nanosized objects in thin, spin cast films of the block copolymers on mica substrates. Since their size and structure may be engineered via directed mutations in the amino acid sequence, these nano‐objects may be interesting building blocks for the development of supramolecular materials with various potential applications.
Discovery of the New Metastable HONF. Radical
Authors: Cacace Fulvio , de Petris Giulia , Rosi Marzio , Troiani Anna
Published: April 2004

The new radical HONF has been detected in the gas phase by neutralization–reionization mass spectrometry (NRMS). The radical has been identified and directly characterized as a gaseous isolated species, having a lifetime of at least 1 μs and a linear cis–trans structure of H‐O‐N‐F connectivity. Detection of this molecule, which is highly unstable towards the dissociation into HF and NO and kinetically sufficiently stable to be observed, represents an advance in the search for high‐energy species.
Thioacetylacetone: Structural and Vibrational Assignments
Authors: Posokhov Yevgen , Gorski Alexander , Spanget‐Larsen Jens , Duus Fritz , Hansen Poul Erik , Waluk Jacek
Published: April 2004

Thioacetylacetone and its variously deuterated isotopomers have been investigated using electronic and vibrational spectroscopy combined with quantum chemical calculations. Thioacetylacetone is known for its photochromic properties, but the structures of the initial and final forms have been the subject of a long debate. Analysis of the IR spectra recorded in low‐temperature argon and xenon matrices, room‐temperature solutions, and in the gas phase has allowed us to establish the nature of the photochromic species and of its precursor. Similar to the case of another β‐thioxoketone, monothiodibenzoylmethane, the photoproduct has been assigned to the nonchelated SH exo‐rotamer of the (Z)‐enethiol tautomeric form, whereas the dominant ground‐state species corresponds to the chelated (Z)‐enol tautomeric form. Detailed vibrational assignments have been proposed for both forms based on quantum chemical calculations and polarization experiments. In the case of the chelated (Z)‐enol species prevailing in the ground state, a second‐order perturbative anharmonic analysis at the B3LYP/cc‐pVTZ level indicated strong anharmonic effects associated with the intramolecular hydrogen bond, leading to a shift of more than 600 cm−1 of the wavenumber of the OH‐stretching vibration. A small fraction of the SH endo‐rotameric chelated (Z)‐enethiol form was also detected under unperturbed conditions. The (Z)‐enethiol form can be converted into the (Z)‐enol form by irradiation at 290 nm.
Cover Picture: Modulation of the Work Function in Layer‐by‐Layer Assembly of Metal Nanoparticles and Poly‐L‐lysine on Modified Au Surfaces (ChemPhysChem 4/2004)
Authors: Carrara Michel , Kakkassery Joseph J. , Abid Jean‐Pierre , Fermín David J.
Published: April 2004

The cover picture shows the modulation of the work function in the layer‐by‐layer growth of assemblies of Au nanoparticles of 19±2 nm diameter and poly‐L‐lysine on Au surfaces. The decrease in the amplitude of modulation with increasing number of layers is associated with disordering in the 3D assembly. This disordering manifests itself in the increment of the surface roughness as illustrated in the 500×500 nm2 AFM images of the first and fifth layer of particles. On page 571, Carrara et al. demonstrate that the modulation of the work function in multilayered materials is dependent on the size and nature of the metal nanoparticles.
Proposal and performance evaluation of a packet over VDSL protocol for increasing throughput in the transmission of IP packets
Authors: Chiaraluce Franco , Gambi Ennio , Pierleoni Paola , Spinsante Susanna
Published: April 2004

This paper presents a possible implementation of a Packet over very high bit rate digital subscriber line protocol with reduced impact of the overhead when transmitting Internet protocol packets. The proposal relates to some shared opinions about the inefficiency of the asynchronous transfer mode (ATM) layer when used to transport this kind of packets, and it is based on proper adaptation of previous recommendations and standards. It is numerically shown that a significant throughput increase is achieved when the new protocol is used in place of the current ATM adaptation layer type 5/ATM protocol. Copyright © 2004 John Wiley & Sons, Ltd.
A direct comparative framework of customer satisfaction: An application to Internet search engines
Authors: Wu Jianan , Padgett Dan
Published: April 2004

Traditionally, satisfaction evaluations have been studied in the expectancy-disconfirmation paradigm in which customers compare firm performance to expectations. The current customer-satisfaction framework incorporates competitive comparisons indirectly through expectations. However, in markets in which competing alternatives are often primed in the evaluation context (e.g., product and retailer information presented in Bizrate.com), customers may directly compare performance and satisfaction across competing alternatives.

In this article, we develop a direct comparative framework (DCF) of customer satisfaction. To make our DCF managerially useful, we also develop an operational model that managers can use to draw strategic insights based on customers’ satisfaction evaluations. We demonstrate our framework and operational model by applying them to the Internet search-engine market.
Genetic analysis of bulimia nervosa: Methods and sample description
Authors: Kaye Walter H. , Devlin Bernie , Barbarich Nicole , Bulik Cynthia M. , Thornton Laura , Bacanu Silviu‐Alin , Fichter Manfred M. , Halmi Katherine A. , Kaplan Allan S. , Strober Michael , Woodside D. Blake , Bergen Andrew W. , Crow Scott , Mitchell James , Rotondo Alessandro , Mauri Mauro , Cassano Giovanni , Keel Pamela , Plotnicov Katherine , Pollice Christine , Klump Kelly L. , Lilenfeld Lisa R. , Ganjei J. Kelly , Quadflieg Norbert , Berrettini Wade H.
Published: April 2004

Objective

Twin and family studies suggest that genetic variants contribute to the pathogenesis of bulimia nervosa (BN) and anorexia nervosa (AN). The Price Foundation has supported an international, multisite study of families with these disorders to identify these genetic variations. The current study presents the clinical characteristics of this sample as well as a description of the study methodology.

Method

All probands met modified criteria for BN or bulimia nervosa with a history of AN (BAN) as defined in the 4th ed. of the Diagnostic and Statistical Manual of Mental Disorders (DSM‐IV; American Psychiatric Association, 1994). All affected relatives met DSM‐IV criteria for BN, AN, BAN, or eating disorders not otherwise specified (EDNOS). Probands and affected relatives were assessed diagnostically using both trained‐rater and self‐report assessments. DNA samples were collected from probands, affected relatives, and available biologic parents.

Results

Assessments were obtained from 163 BN probands and 165 BAN probands. Overall, there were 365 relative pairs available for linkage analysis. Of the affected relatives of BN probands, 62 were diagnosed as BN (34.8%), 49 as BAN (27.5%), 35 as AN (19.7%), and 32 as EDNOS (18.0%). For the relatives of BAN probands, 42 were diagnosed as BN (22.5%), 67 as BAN (35.8%), 48 as AN (25.7%), and 30 as EDNOS (16.0%).

Discussion

This study represents the largest genetic study of eating disorders to date. Clinical data indicate that although there are a large number of individuals with BN disorders, a range of eating pathology is represented in the sample, allowing for the examination of several different phenotypes in molecular genetic analyses. © 2004 by Wiley Periodicals, Inc. Int J Eat Disord 35: 556–570, 2004.
Electrochemical Sensor for Sulfite and Sulfur Dioxide Based on 3‐Aminopropyltrimethoxysilane Derived Sol‐Gel Composite Electrode
Authors: Ravi Shankaran Dhesingh , Iimura Ken‐Ichi , Kato Teiji
Published: April 2004

A new sol‐gel derived composite sensor has been developed for the determination of sulfite and sulfur dioxide using 3‐aminopropyltrimethoxysilane, ferrous sulfate and graphite powder by sol‐gel process. Cyclic voltammetry and amperometry studies revealed that the modified iron dispersed sol‐gel derived ceramic composite electrode exhibited excellent characteristics for the electrocatalytic oxidation of sulfite at a reduced potential of +0.35 V with good sensitivity and selectivity. The pH and the potential for sulfite estimation have been optimized. The sensor exhibited rapid and linear response to sulfite in the concentration range from 0.73 mg/L to 95.42 mg/L with a correlation coefficient of 0.997. The proposed sensor can be utilized for the determination sulfur dioxide after absorbing in a suitable medium and has promising characteristics such as, rapid response, good reproducibility and remarkable stability.
An experimental and computer simulation study of erosion on a mine tailings dam wall
Authors: Hancock G. R. , Willgoose G. R.
Published: April 2004

Mine tailings dams pose a signiﬁcant risk to the environment if not correctly designed, built and maintained. The effect of erosion on a back‐ﬁlled and capped earthen dam wall was examined by construction of an analogue in an experimental model landscape simulator. The ability of a computer‐based erosion model to simulate erosion processes on the experimental structure was examined. The experimental landscape simulator uses a rainfall simulator to create overland ﬂow and erode an artiﬁcial soil. At the commencement of rainfall, erosion occurred rapidly with deep gullies developing on the dam wall batter. The gullies developed by downcutting, with consequent bank collapse and slumping, and followed ﬂow lines towards their source. A physically based erosion model (SIBERIA) was used to simulate erosion on the experimental dam wall. Erosion and consequent development of the experimental structure were modelled by SIBERIA. The ability of SIBERIA to model incision and landscape development in the experimental setting was further examined by use of a simple one‐dimensional experimental catchment. The laboratory experiment and computer simulations demonstrated that erosion on the tailings dam is driven by concentrated runoff and that runoff control is crucial to the long‐term stability of such structures. The study demonstrates that computer‐based erosion models can be used to predict how erosion occurs on the experimental landscapes examined, thus providing conﬁdence in their use and application. Copyright © 2004 John Wiley & Sons, Ltd.
Asymmetries in conditional mean and variance: modelling stock returns by asMA‐asQGARCH
Authors: Brännäs Kurt , Gooijer Jan G. De
Published: April 2004

We propose a nonlinear time series model where both the conditional mean and the conditional variance are asymmetric functions of past information. The model is particularly useful for analysing financial time series where it has been noted that there is an asymmetric impact of good news and bad news on volatility (risk) transmission. We introduce a coherent framework for testing asymmetries in the conditional mean and the conditional variance, separately or jointly. To this end we derive both a Wald and a Lagrange multiplier test. Some of the new asymmetric model's moment properties are investigated. Detailed empirical results are given for the daily returns of the composite index of the New York Stock Exchange. There is strong evidence of asymmetry in both the conditional mean and the conditional variance functions. In a genuine out‐of‐sample forecasting experiment the performance of the best fitted asymmetric model, having asymmetries in both conditional mean and conditional variance, is compared with an asymmetric model for the conditional mean, and with no‐change forecasts. This is done both in terms of conditional mean forecasting as well as in terms of risk forecasting. Finally, the paper presents some evidence of asymmetries in the index stock returns of the Group of Seven (G7) industrialized countries. Copyright © 2004 John Wiley & Sons, Ltd.
Information on ancestry from genetic markers
Authors: Pfaff Carrie Lynn , Barnholtz‐Sloan Jill , Wagner Jennifer K. , Long Jeffrey C.
Published: April 2004

It is possible to estimate the proportionate contributions of ancestral populations to admixed individuals or populations using genetic markers, but different loci and alleles vary considerably in the amount of information that they provide. Conventionally, the allele frequency difference between parental populations (δ) has been used as the criterion to select informative markers. However, it is unclear how to use δ for multiallelic loci, or populations formed by the mixture of more than two groups. Moreover, several other factors, including the actual ancestral proportions and the relative genetic diversities of the parental populations, affect the information provided by genetic markers. We demonstrate here that using δ as the sole criterion for marker selection is inadequate, and we propose, instead, to use Fisher's information, which is the inverse of the variance of the estimated ancestral contributions. This measure is superior because it is directly related to the precision of ancestry estimates. Although δ is related to Fisher's information, the relationship is neither linear nor simple, and the information can vary widely for markers with identical δs. Fortunately, Fisher's information is easily computed and formally extends to the situation of multiple alleles and/or parental populations. We examined the distribution of information for SNP and microsatellite loci available in the public domain for a variety of model admixed populations. The information, on average, is higher for microsatellite loci, but exceptional SNPs exceed the best microsatellites. Despite the large number of genetic markers that have been identified for admixture analysis, it appears that information for estimating admixture proportions is limited, and estimates will typically have wide confidence intervals. © 2004 Wiley‐Liss,Inc.
FK506 enhances regeneration of axons across long peripheral nerve gaps repaired with collagen guides seeded with allogeneic Schwann cells
Authors: Udina Esther , Rodríguez Francisco J. , Verdú Enrique , Espejo Mónica , Gold Bruce G. , Navarro Xavier
Published: April 2004

We assessed the effects of FK506 administration on regeneration after a 6‐mm gap repair with a collagen guide seeded with allogeneic Schwann cells (SCs) in the mouse sciatic nerve. SCs were isolated from predegenerated adult sciatic nerves and expanded in culture using a defined medium, before being seeded in the collagen guide embedded in Matrigel. Functional reinnervation was evaluated by noninvasive methods to determine recovery of motor, sensory, and autonomic functions in the hindpaw over 4 months postoperation. Histological analysis of the regenerated nerves was performed at the end of the study. Using simple collagen guides for tubulization repair, treatment with an immunosuppressant dose of FK506 (5 mg/kg/day) resulted in significant improvement of the onset and the degree of reinnervation. While the introduction of allogeneic SCs did not improve regeneration versus a collagen guide filled only with Matrigel, treatment with FK506 allowed for successful regeneration in all the mice and for significant improvement in the levels of functional recovery. Compared with the untreated group, there was greater survival of transplanted pre‐labeled SCs in the FK506‐treated animals. Morphologically, the best nerve regeneration (in terms of nerve caliber and numbers of myelinated axons) was obtained with SC‐seeded guides from FK506‐treated animals. Thus, FK506 should be considered as adjunct therapy for various types of tubulization repair. © 2004 Wiley‐Liss, Inc.
Migratory capacity of the cell line RN33B and the host glial cell response after subretinal transplantation to normal adult rats
Authors: Blixt Wojciechowski Anita , Englund Ulrica , Lundberg Cecilia , Warfvinge Karin
Published: April 2004

As previously reported, the brain‐derived precursor cell line RN33B has a great capacity to migrate when transplanted to adult brain or retina. This cell line is immortalized with the SV40 large T‐antigen and carries the reporter gene LacZ and the green fluorescent protein GFP. In the present study, the precursor cells were transplanted to the subretinal space of adult rats and investigated early after grafting. The purpose was to demonstrate the migration of the grafted cells from the subretinal space into the retina and the glial cell response of the host retina. Detachment caused by the transplantation method was persistent up to 4 days after transplantation, and then reattachment occurred. The grafted cells were shown to migrate in between the photoreceptor cells before entering into the plexiform layers. Molecules involved in migration of immature neuronal cells as the polysialylated neural cell adhesion molecule (PSA‐NCAM) and the collapsing response‐mediated protein 4 (TUC‐4) was found in the plexiform layers of the host retina, but not in the grafted cells. The expression of the intermediate filaments GFAP, vimentin, and nestin was intensely upregulated immediately after transplantation. A less pronounced upregulation was observed on sham‐operated animals. In summary, the RN33B cell line migrated promptly posttransplantation and settled preferably into the plexiform layers of the retina, the same layers where the migration cues PSA‐NCAM and TUC‐4 were established. In addition, both the transplantation method per se and the implanted cells caused an intense glial cell response by the host retina. © 2004 Wiley‐Liss, Inc.
Cycloaddition reactions of heterophospholes
Authors: Bansal Raj K. , Gupta Neelima , Gupta Nidhi
Published: April 2004

The cycloaddition reactions namely, [2 + 4], [4 + 2], [2 + 3] and [1 + 4] given by the heterophospholes, which are five‐membered 6π aromatic heterocycles containing at least one σ2, λ3 phosphorus, are reviewed in the present article. Different aspects of these reactions such as stereoselectivity, regioselectivity, relative reactivities and theoretical correlations thereof are included. The literature has been surveyed up to December 2003. © 2004 Wiley Periodicals, Inc. Heteroatom Chem 15:271–287, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20002
The first general synthesis of 3‐iodo‐4‐R‐furazans
Authors: Sheremetev Aleksei B. , Shamshina Julia L. , Dmitriev Dmitry E. , Lyubetskii Denis V. , Antipin Mikhail Yu.
Published: April 2004

The first general synthetic route has been developed for the convenient preparation of iodofurazans. The approach was accomplished by one‐pot diazotization‐iodation reaction of appropriate aminofurazans. A combination of sodium nitrite and iodine in organic solvent under anhydrous conditions as the reaction conditions allowed to solve problem in iodofurazans preparation. The investigation of the substituent's influence on NMR data of the iodofurazans has been carried out. The X‐ray crystal structure of the 3‐amino‐4‐iodofurazan 1d is reported. © 2004 Wiley Periodicals, Inc. Heteroatom Chem 15:199–207, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20007
Design of novel podand‐like compounds with two short diphenylphosphine oxide pendant arms
Authors: Kruszynski Rafal , Wieczorek Wanda
Published: April 2004

Crystal and molecular structure of 1,3,5‐benzenetris(methylenediphenylphosphine oxide) cyclohexylammonium chloride dibenzene solvate monohydrate has been determined. The overall arrangement of two diphenylphosphine oxide substituents atoms is imposed by intermolecular strong hydrogen bonds, O(water)H···O(oxide) and NH···O(oxide, water). Cyclohexylamine exists in almost ideal chair conformation and nitrogen atom is equatorial to the ring. The structure is build up from strong and weak intermolecular hydrogen bonds to form the three‐dimensional infinite hydrogen bond network.

Crystal and molecular structure of 1,4‐bis[(diphenylphosphineoxide)methyl] ‐ 2,5 ‐ bis (ethoxymethyl) benzene has been determined. The phenyl rings are inclined at 80.91(7)° within the substituent, and they are involved in weak C(phenyl)H···O(oxide) hydrogen bonds. The arrangement of diphenylphosphine oxide substituents is imposed practically only by steric effects. Two intramolecular weak hydrogen bonds exist between diphenylphosphine oxide and ethoxymethyl substituents, which can provide additional stabilization to molecule, but it has no noticeable influence on overall molecule geometry. Molecules are assembled via weak intermolecular CH···O(oxide) hydrogen bonds to the one‐dimensional hydrogen‐bonded chain along y axis. © 2004 Wiley Periodicals, Inc. Heteroatom Chem 15:233–240, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20008
Quantum chemical estimation of reactivity of 2,3,4,5‐tetrahydro‐1,5‐benzodiazepin‐2(1H)‐ones in electrophilic aromatic substitution
Authors: Vektariene Ausra , Vektaris Gytis
Published: April 2004

DFT B3LYP calculation study was employed to estimate the regioselectivity of an electrophilic aromatic substitution in functionalized 2,3,4,5‐tetrahydro‐1,5‐benzodiazepin‐2(1H)‐ones. Charge density, frontier molecular orbital study, energetics of σ‐complex intermediates of electrophilic substitution reactions in the 2,3,4,5‐tetrahydro‐1,5‐benzodiazepin‐2(1H)‐ones yield information on different reactivity of aromatic sites. © 2004 Wiley Periodicals, Inc. Heteroatom Chem 15:263–270, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20015
High‐resolution imaging of the thyroid gland using optical coherence tomography
Authors: Pantanowitz Liron , Hsiung Pei‐Lin , Ko Tony H. , Schneider Karl , Herz Paul R. , Fujimoto James G. , Raza Sughra , Connolly James L.
Published: April 2004

Background.

Current diagnostic imaging modalities of the thyroid gland cannot reliably distinguish benign from malignant lesions, primarily because of their inability to visualize microscopic structure. A high‐resolution imaging technique capable of examining thyroid tissue architectural morphology in real time is needed. Optical coherence tomography (OCT) has been shown to achieve high resolutions approaching the cellular range (1–15 μm). The feasibility of optical coherence tomography for imaging thyroid tissue was explored ex vivo on the human thyroid gland.

Methods.

High‐resolution OCT was performed in real time at 2 to 4 frames per second on three postmortem and 15 surgically excised thyroid glands containing normal, hyperplastic, and neoplastic tissue. OCT images acquired were compared with those obtained using standard histopathologic methods.

Results.

The microstructure of the normal thyroid gland, including colloid‐filled follicles as small as 15 μm and their supporting stroma, was clearly identified. OCT images of degenerative, hyperplastic, adenomatous, and malignant change within the thyroid gland were shown to correlate well with corresponding histopathologic findings.

Conclusions.

The ability of OCT to image thyroid tissue microarchitecture makes it a potentially powerful technology that can be used to assess the thyroid gland at a resolution greater than currently available clinical imaging modalities. © 2004 Wiley Periodicals, Inc. Head Neck 26: 425–434, 2004
Previous chemotherapy as a predictor of wound infections in nonmajor head and neck surgery: Results of a prospective study
Authors: Penel Nicolas , Fournier Charles , Lefebvre Danièle , Roussel‐Delvallez Micheline , Sarini Jérome , Kara Ahmed , Mallet Yann , Lefebvre Jean‐Louis
Published: April 2004

Background.

The goal of this prospective study was to determine the incidence of wound infections (WI) after clean uncontaminated head and neck cancer procedures and after emergency tracheotomies.

Methods.

Two hundred twelve clean procedures without tracheotomy or opening of mucosa (neck dissections, large skin resections, thyroidectomies, parotid gland resections, and explorative cervicotomies) were studied at Oscar Lambret Cancer Center over a 24‐month period.

Results.

WI rate was 6.6% (14 of 212). In a univariate analysis, only one variable was significantly related to the likelihood of WI: previous anticancer chemotherapy. All but one patient who had had previous chemotherapy demonstrated WI (14 of 15).

Conclusions.

After previous chemotherapy, WI rate in clean uncontaminated head and neck surgery was as high as 90%. In this case, antibiotic prophylaxis should be evaluated. © 2004 Wiley Periodicals, Inc. Head Neck 26: 513–517, 2004
Accuracy of visual screening for cervical neoplasia: Results from an IARC multicentre study in India and Africa
Authors: Sankaranarayanan Rengaswamy , Basu Parthasarathy , Wesley Ramani S. , Mahe Cédric , Keita Namory , Mbalawa Charles C. Gombe , Sharma Rameshwar , Dolo Amadou , Shastri Surendra S. , Nacoulma Marius , Nayama Madi , Somanathan Thara , Lucas Eric , Muwonge Richard , Frappart Lucien , Parkin D. Maxwell ,   for the IARC Multicentre Study Group on Cervical Cancer Early Detection
Published: April 2004

Visual inspection‐based screening tests, such as visual inspection with 4% acetic acid (VIA) and with Lugol's iodine (VILI), have been proposed as alternatives to cytology in mass screening programs. To date, there is only limited information on the accuracy of these tests in detecting High‐grade Squamous Intraepithelial Lesions (HSIL). Eleven cross‐sectional studies involving 56,939 women aged 25–65 years were conducted in Burkina Faso, Congo, Guinea, India, Mali and Niger to evaluate the accuracy of VIA and VILI performed by health workers. A common protocol and questionnaire was used. For final diagnosis, all women were investigated with colposcopy and biopsies were taken when necessary. Data from the studies were pooled to calculate sensitivity, specificity and predictive values of the tests for the detection of HSIL. Of the screened women, 16.1% and 16.4% were positive on examination using, respectively, VIA and VILI; 1,063 were diagnosed with HSIL. The pooled sensitivity, specificity, positive and negative predictive values for VIA were 76.8% (95% CI: 74.2–79.4%), 85.5% (95% CI: 85.2–85.8%), 9.4% (95% CI:8.8–10.8%) and 99.5% (95% CI:99.4–99.6%), respectively. The values were 91.7% (95% CI: 89.7–93.4%), 85.4% (95% CI: 85.1–85.7%), 10.9% (95% CI: 10.2–11.6%) and 99.8% (95% CI:99.7–99.9%), respectively for VILI. The range of sensitivity and specificity for VIA was 56.1–93.9% and 74.2–93.8%, respectively, between studies and were 76.0–97.0 % and 73.0–91.3% for VILI. VILI had a significantly higher sensitivity than VIA in detecting HSIL, but specificity was similar. VILI appears to be a more accurate visual test for use in screening and treatment programs in low‐resource settings. © 2004 Wiley‐Liss, Inc.
Genetic evolution in colon cancer KM12 cells and metastatic derivates
Authors: Camps Jordi , Morales Cristina , Prat Esther , Ribas Maria , Capellà Gabriel , Egozcue Josep , Peinado Miguel A. , Miró Rosa
Published: April 2004

So far, CRC cell lines have contributed to descriptions of 2 patterns of genetic instability, affecting either microsatellite sequences or chromosome number and structure. Often, these patterns are mutually exclusive; while near‐diploid karyotypes usually appear with MSI and chromosomal stability, near‐triploid or tetraploid cells display a high degree of CIN and are stable at the microsatellite level. In the present study, we describe the genomic instability pattern of KM12 CRC cells. KM12C and derived cell lines with different metastatic properties were analyzed by conventional cytogenetics, CGH and M‐FISH. Results were compared to 5 cell lines usually used as model of MSI and CIN. Concordance between our results and previously published SKY data are also reviewed. Interestingly, the poorly metastatic KM12C cell line displayed a near‐diploid karyotype with high levels of structural chromosome instability and microsatellite instability. The highly metastatic KM12SM and KM12L4A cell lines showed polyploid karyotypes and maintained CIN and MSI. A comparison between karyotypes of poorly and highly metastatic KM12 cell lines allowed us to delineate a cytogenetic evolution pathway. Our results clearly demonstrated that endoreduplication was the origin of the polyploid dosages in the highly metastatic forms following the monosomic model postulated for CRC. Therefore, we demonstrate that KM12C cells and their metastatic derivates, KM12SM and KM12L4A, are a useful model of chromosomal evolution where MSI may coexist with CIN. © 2004 Wiley‐Liss, Inc.
Molecular classification of oral cancer by cDNA microarrays identifies overexpressed genes correlated with nodal metastasis
Authors: Warner Giles C. , Reis Patricia P. , Jurisica Igor , Sultan Mujahid , Arora Shilpi , Macmillan Christina , Makitie Antti A. , Grénman Reidar , Reid Nancy , Sukhai Mahadeo , Freeman Jeremy , Gullane Patrick , Irish Jonathan , Kamel‐Reid Suzanne
Published: April 2004

Our purpose was to classify OSCCs based on their gene expression profiles, to identify differentially expressed genes in these cancers and to correlate genetic deregulation with clinical and histopathologic data and patient outcome. After conducting proof‐of‐principle experiments utilizing 6 HNSCC cell lines, the gene expression profiles of 20 OSCCs were determined using cDNA microarrays containing 19,200 sequences and the BTSVQ method of data analysis. We identified 2 sample clusters that correlated with the T3‐T4 category of disease (p = 0.035) and nodal metastasis (p = 0.035). BTSVQ analysis identified a subset of 23 differentially expressed genes with the lowest QE scores in the cluster containing more advanced‐stage tumors. Expression of 6 of these differentially expressed genes was validated by quantitative real‐time RT‐PCR. Statistical analysis of quantitative real‐time RT‐PCR data was performed and, after Bonferroni correction, CLDN1 overexpression was significantly correlated with the cluster containing more advanced‐stage tumors (p = 0.007). Despite the clinical heterogeneity of OSCC, molecular subtyping by cDNA microarray analysis identified distinct patterns of gene expression associated with relevant clinical parameters. Application of this methodology represents an advance in the classification of oral cavity tumors and may ultimately aid in the development of more tailored therapies for oral carcinoma. © 2004 Wiley‐Liss, Inc.