bluuebunny/crossref_metadata_2025 huggingface dataset:
Abrasively Immobilised Multiwalled Carbon Nanotube Agglomerates: A Novel Electrode Material Approach for the Analytical Sensing of pH
Authors: Wildgoose Gregory G. , Leventis Henry C. , Streeter Ian , Lawrence Nathan S. , Wilkins Shelley J. , Jiang Li , Jones Timothy G. J. , Compton Richard G.
Published: May 2004

We demonstrate for the first time that agglomerates of multiwalled carbon nanotubes (MWCNTs) can be formed in which the binder in the agglomerate is itself a redox‐active molecular solid. Two separate agglomerates were formed by dissolving 9,10‐phenanthraquinone (PAQ) or 1,2‐napthaquinone (NQ) in acetone together with MWCNTs and adding an excess of aqueous solution to cause precipitation of agglomerates, approximately 10 µ;m in dimension, which consist of bundles of nanotubes running into and throughout the amorphous molecular solid that binds the agglomerate together. The nature of this structure, when immobilised on a substrate electrode and in contact with aqueous electrolyte solutions, gives rise to many three‐phase boundaries, electrolyte|agglomerate|conductor, which is advantageous to the solid‐state analytical electrochemistry of such a material as it imparts a larger electroactive surface area than other modified carbon electrodes.

The two agglomerates each gave a voltammetrically measurable response to changes in pH; when abrasively immobilised on a basal plane pyrolitic graphite electrode a plot of peak potential against pH produced a linear response for both MWCNT–PAQ and MWCNT–NQ agglomerates over the pH range pH 1–12 and over the temperature range 20–70 °C.
Molecular Beams and Model Catalysis: Activity and Selectivity of Specific Reaction Centers on Supported Nanoparticles
Authors: Libuda Jörg
Published: May 2004

Reaction kinetics on nanometer‐scale particles are different from those on extended surfaces of bulk materials. This fact has been utilized for a long time to empirically maximize the performance of heterogeneous catalysts, but the understanding of the underlying effects is poor at the microscopic level. Modern molecular‐beam‐based methods, however, allow us to derive very detailed kinetic information on catalytically active surfaces. In combination with structurally highly controlled model catalysts, microscopic insights into the activity and selectivity of specific reaction centers on catalyst nanoparticles can be obtained. This combined approach is illustrated through simple model reactions.
Determination of nitrate and nitrite in rat brain perfusates by capillary electrophoresis
Authors: Gao Leyi , Barber‐Singh Jennifer , Kottegoda Sumith , Wirtshafter David , Shippy Scott A.
Published: May 2004

A fast and simple method for the direct, simultaneous detection of nitrite (NO2−) and nitrate (NO3−) in rat striatum has been developed using a capillary electrophoresis separation of low‐flow push‐pull perfusion samples. The method was optimized primarily for nitrite because nitrite is more important physiologically and is found at lower levels than nitrate. We obtained a complete separation of NO2− and NO3− in rat striatum within 1.5 min. Optimal CE separations were achieved with 20 mM phosphate, 2 mM cetyltrimethylammonium chloride (CTAC) buffer at pH 3.5. The samples were injected electrokinetically for 2 s into a 40 cm×75 μm ID fused‐silica capillary. The separation voltage was 10 kV (negative polarity), and the injection voltage was 16 kV (negative polarity). UV detection was performed at 214 nm. The limits of detection obtained at a signal‐to‐noise ratio (S/N) of 3 for nitrite and nitrate were 0.96 and 2.86 μM. This is one of the fastest separations of nitrite and nitrate of a biological sample ever reported. Interference produced by the high physiological level of chloride is successfully minimized by use of CTAC in the run buffer.
On‐line protein digestion and peptide mapping by capillary electrophoresis with post‐column labeling for laser‐induced fluorescence detection
Authors: Ye Mingliang , Hu Shen , Schoenherr Regine M. , Dovichi Norman J.
Published: May 2004

A nanoliter enzyme microreactor was developed for on‐line capillary electrophoresis (CE) peptide mapping of proteins, allowing picomole quantities of proteins to be digested. The enzyme microreactor was formed by immobilizing trypsin onto a monolithic capillary column, which was prepared by in situ polymerization of glycidyl methacrylate and ethylene dimethacrylate in a capillary. Highly efficient digestion of three protein standards was demonstrated. The detection of peptide fragments in CE was enhanced by post‐column derivatization and laser‐induced fluorescence detection. The microreactor has a volume of about 30 nL and is coupled with a separation capillary via a fluid joint for on‐line digestion. The overall analysis, including digestion and separation, lasted only about 16 min. Column efficiencies > 300 000 plates/m were obtained for most peaks in the electropherogram of an on‐line peptide mapping experiment of denatured α‐lactalbumin under optimal conditions.
Blue silver: A very sensitive colloidal Coomassie G‐250 staining for proteome analysis
Authors: Candiano Giovanni , Bruschi Maurizio , Musante Luca , Santucci Laura , Ghiggeri Gian Marco , Carnemolla Barbara , Orecchia Paola , Zardi Luciano , Righetti Pier Giorgio
Published: May 2004

A modified Neuhoff's colloidal Coomassie Blue G‐250 stain is reported, dubbed “blue silver” on account of its considerably higher sensitivity, approaching the one of conventional silver staining. The main modifications, as compared to Neuhoff's protocol, were: a 20% increment in dye concentration (from 0.1% up to 0.12%) and a much higher level of phosphoric acid in the recipe (from 2% up to 10%). The “blue silver” exhibits a much faster dye uptake (80% during the first hour of coloration, vs. none with a commercial preparation from Sigma). Even at equilibrium (24 h staining), the “blue silver” exhibits a much higher sensitivity than all other recipes, approaching (but lower than) the one of the classical silver stain. Measurements of stain sensitivity after sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE) of bovine serum albumin (BSA) gave a detection limit (signal‐to‐noise ratio > 3) of 1 ng in a single zone. The somewhat lower sensitivity of “blue silver” as compared to classical silvering protocols in the presence of aldehydes is amply compensated for by its full compatibility with mass spectrometry of eluted polypeptide chains, after a two‐dimensional map analysis, thus confirming that no dye is covalently bound (or permanently modifies) to any residue in the proteinaceous material. It is believed that the higher level of phosphoric acid in the recipe, thus its lower final pH, helps in protonating the last dissociated residues of Asp and Glu in the polypeptide coils, thus greatly favoring ionic anchoring of dye molecules to the protein moiety. Such a binding, though, must be followed by considerable hydrophobic association with the aromatic and hydrophobic residues along the polypeptide backbone.
Intact mass measurements for unequivocal identification of hydrophobic photosynthetic photosystems I and II antenna proteins
Authors: Zolla Lello , Rinalducci Sara , Timperio Anna Maria , Huber Christian G. , Righetti Pier Giorgio
Published: May 2004

The purpose of this study was to determine the optimal experimental conditions necessary to allow rapid and accurate identification of highly hydrophobic proteins, such as the antenna proteins from photosystems I and II. The antenna proteins were derived from two different species, tomato and Arabidopsis, whose photosynthetic genome is well known. The separation techniques included sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE) followed by immunoblotting, microamino acid sequencing, reversed‐phase high‐performance liquid chromatography (RP‐HPLC), intact mass measurements, and peptide mass fingerprinting by mass spectrometry. Immunoblotting was time‐consuming, and success was limited due to cross‐reactivity between these highly conserved sequences. The best results by far were achieved by separating intact proteins through hyphenation of reversed‐phase liquid chromatography on‐line to an electrospray ionization mass spectrometer (ESI‐MS) and consequently identifying individual proteins from their intact mass measurements (IMMs), whereas peptide mass fingerprinting was hampered by the highly hydrophobic nature of these proteins. RP‐HPLC‐ESI‐MS was superior in the quality of separation. Moreover, the high quality of mass spectra recorded during the RP‐HPLC‐ESI‐MS analysis meant that the relative deviations of the molecular masses determined with a quadrupole ion trap mass analyzer ranged between 100 and 300 ppm. Thus, the correspondence between the intact mass values measured with those deduced from the DNA sequences allowed the different types of antenna proteins to be identified and assigned to their corresponding gene families. By utilizing this correlation, it was possible to spot gene products of previously cloned genes.
Comparison of two glutaraldehyde immobilization techniques for solid‐phase tryptic peptide mapping of human hemoglobin by capillary zone electrophoresis and mass spectrometry
Authors: Migneault Isabelle , Dartiguenave Catherine , Vinh Joëlle , Bertrand Michel J. , Waldron Karen C.
Published: May 2004

Stabilization of proteolytic enzymes, especially by immobilization, is of considerable interest because of their potential applications in medicine and the chemical and pharmaceutical industries. We report here a detailed comparison of two procedures for trypsin immobilization using the same homobifunctional agent, glutaraldehyde, for the purpose of peptide mapping. These methods include covalent coupling either to controlled pore glass (solid support) or via a cross‐linking reaction (without any solid support). The immobilized trypsin preparations were characterized by the determination of immobilization efficiency, which ranged from 68 to > 95%, and measurement of apparent kinetic parameters toward a synthetic peptide‐like substrate. Batch digestions of whole denaturated human normal adult hemoglobin (HbA) were performed to obtain peptide maps by capillary zone electrophoresis (CZE). Migration time reproducibility of the CZE maps was excellent, with a mean relative standard deviation of 1.5%. Moreover, the two immobilized enzyme preparations showed excellent reproducibility for repeated digestions. Matrix‐assisted laser desorption/ionization (MALDI)‐mass spectrometry was also used for peptide mass mapping of denaturated HbA digested using the two immobilized trypsin preparations. Even though the two immobilized trypsin preparations do not behave identically, similar sequence coverages of 57% and 61% (for the two HbA chains merged) were achieved for the support‐based and cross‐linked trypsin preparations, respectively.
Peptide separations by slab gel electrophoresis in Pluronic F127 polymer liquid crystals
Authors: Rill Randolph L. , Al‐Sayah Mohammad A.
Published: May 2004

Proteomics and peptidomics could benefit from simple methods for high‐resolution separation of oligopeptides analogous to slab gel electrophoresis of proteins. Gels of Pluronic F127 copolymer surfactant were investigated as media for slab gel electrophoresis of oligopeptides using a trypsin digest of myoglobin. Concentrated solutions of Pluronic F127 are fluid at low temperatures (≤ 5°C), but become a gel‐like micellar liquid crystal upon warming. Nucleic acids are well separated by electrophoresis in these gels as previously shown by Rill and Liu. Good separations of myoglobin tryptic peptides were accomplished by electrophoresis on slab gels of 24% Pluronic F127 or 15% polyacrylamide using the alkaline Laemmli buffer system (without sodium dodecyl sulfate). Labeling of peptides with the succinimidyl ester of Cascade Yellow (CY) prior to electrophoresis allowed sensitive detection with blacklight illumination at 365 nm. Labeled tryptic peptides were identified by matrix‐assisted laser desorption/ionization‐time of flight (MALDI‐TOF)‐mass spectrometry. An inverse dependence of electrophoretic mobility on mass of peptides with charge Z = −1 was observed in both media. Two‐dimensional (2‐D) electrophoresis of myoglobin peptides on polyacrylamide, then on Pluronic media, at pH 8.3 indicated that the primary separation mechanism of most peptides was the same in both media. A few off‐diagonal spots indicated that some peptides were preferentially retarded in Pluronic gels, perhaps due to hydrophobic effects. The ease of gel preparation and peptide recovery are advantages of Pluronic F127 gels for oligopeptide electrophoresis. The two media can be combined conveniently for 2‐D electrophoresis, providing means to facilitate protein identification and peptidomics.
Capillary electrophoresis of single mammalian cells
Authors: Woods Lori A. , Roddy Thomas P. , Ewing Andrew G.
Published: May 2004

Capillary electrophoresis (CE) has been established as powerful tool for single cell analysis. Newly developed sampling, separation and detection methods have allowed the investigation of single mammalian cells with CE despite their small size and complex composition. Advances in sample injection techniques include several novel methods for the injection of whole cells and sampling techniques for the study of cellular secretion. CE of single mammalian cells has been applied in a wide range of fields including protein analysis, neuroscience, and oncology. The development of new detection schemes in the analysis of single mammalian cells with CE has included studies of protein expression and the utilization of mass spectrometric and electrochemical detection. Subcellular mammalian cell analysis with CE also has been investigated.
Selectivity of quadruplex DNA stationary phases toward amino acids in homodipeptides and alanyl dipeptides
Authors: Vo Trang U. , McGown Linda B.
Published: May 2004

Series of dipeptides, including homodipeptides and alanyl dipeptides, were separated using quadruplex (G‐quartet) DNA stationary phases in open‐tubular capillary electrochromatography (OTCEC). The stationary phases were constructed by covalently attaching the DNA oligonucleotides to the inner capillary surface. Three different G‐quartet forming oligonucleotides were investigated: the two‐plane G‐quartet forming thrombin‐binding aptamer, the four‐plane analogue of the thrombin‐binding aptamer, and a two‐plane oligonucleotide identical to the thrombin‐binding aptamer except for the replacement of the guanine by thymine in the central bridging loop of the G‐quartet structure. Results were compared with results obtained using capillary electrophoresis on a bare capillary and OTCEC using an oligonucleotide with the same base composition as the thrombin‐binding aptamer but in a different sequence that does not allow G‐quartet formation as the stationary phase.
An investigation into the human serum “interactome”
Authors: Zhou Ming , Lucas David A. , Chan King C. , Issaq Haleem J. , Petricoin Emanuel F. , Liotta Lance A. , Veenstra Timothy D. , Conrads Thomas P.
Published: May 2004

The protein content of human serum is composed of a millieu of proteins from almost every type of cell and tissue within the body. The serum proteome has been shown to contain information that directly reflects pathophysiological states and represents an invaluable source of diagnostic information for a variety of different diseases. Unfortunately, the dynamic range of protein abundance, ranging from ≫ mg/mL level to ≪ pg/mL level, renders complete characterization of this proteome nearly impossible with current analytical methods. To study low‐abundance proteins, which have potential value for clinical diagnosis, the high‐abundant species, such as immunoglobulins and albumin, are generally eliminated as the first step in many analytical protocols. This step, however, is hypothesized to concomitantly remove proteins/peptides associated with the high‐abundant proteins targeted for depletion. In this study, immunoprecipitation was combined with microcapillary reversed‐phase liquid chromatography (μRPLC) coupled on‐line with tandem mass spectrometry (MS/MS) to investigate the low‐molecular‐weight proteins/peptides that associate with the most abundant species in serum. By this targeted isolation of select highly abundant serum proteins, the associated proteins/peptides can be enriched and effectively identified by μRPLC‐MS/MS. Among the 210 proteins identified, 73% and 67% were not found in previous studies of the low‐molecular‐weight or whole‐serum proteome, respectively.
Membrane‐mediated capillary electrophoresis: Interaction of cationic peptides with bicelles
Authors: Mills John O. , Holland Lisa A.
Published: May 2004

Electrokinetic capillary chromatography is applied to determine the membrane affinity of peptides using both 1,2‐dihexanoyl‐sn‐glycero‐3‐phosphocholine (DHPC) micelles and DHPC/1,2‐dimyristoyl‐sn‐glycero‐3‐phosphocholine (DMPC) bicelles under controlled conditions. The effect of temperature and the bicelle q value in surface association with cationic peptides is studied. The cationic peptides selected have a well‐defined membrane structure (indolicidin), induced secondary structure (melittin, magainin 2), or do not possess classical secondary structure (atrial natriuretic peptide (ANP) 1‐28, 4‐28, 5‐27). Electrokinetic capillary chromatography facilitated by DMPC and DHPC additives provides a rapid means of estimating lipophilicity and screening for peptides that have membrane affinity.
Proteomic analysis of carbonylated proteins in two‐dimensional gel electrophoresis using avidin‐fluorescein affinity staining
Authors: Yoo Byoung‐Sam , Regnier Fred E.
Published: May 2004

A method for detecting carbonylated proteins in two‐dimensional electrophoresis (2‐DE) was developed using biotinylation and avidin‐fluorescein isothiocyanate (FITC) affinity staining. The method was used to examine oxidatively modified proteins associated with oxidative stress. Carbonyl formation in proteins was first examined in a model system by subjecting bovine serum albumin (BSA) and ribonuclease A (RNase A) to metal‐catalyzed oxidation (MCO). Carbonyl group formation was found to occur at multiple sites along with a small amount of polypeptide chain cleavage. In vivo studies were conducted in yeast cell cultures using 5 mM hydrogen peroxide to induce oxidative stress. Biotinylation of yeast protein was accomplished during extraction at 4°C in a lysis buffer containing 5 mM biotin‐hydrazide. Biotin‐hydrazide forms a Schiff base with a carbonyl group on an oxidized protein that is subsequently reduced before electrophoresis. Proteins were separated by either 2‐DE or sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE). Biotinylated species were detected using avidin‐FITC affinity staining. Detection sensitivity with biotinylated proteins was five times higher than achieved by silver staining. The limit of detection with avidin‐FITC staining approached 0.64 pmol of protein‐associated carbonyls. Twenty carbonylated proteins were identified in the proteome of yeast following oxidative stress with hydrogen peroxide. Matrix‐assisted laser desorption/ionization‐mass spectrometry (MALDI‐MS) analysis of tryptic peptides was used to identify peptides extracted from gels. Aconitase, heat shock protein SSA1 and SSC1, pyruvate decarboxylase isozyme 1, pyruvate kinase 1, enolase 1 and 2, phosphoglycerate kinase, fructose‐bisphosphate aldorase, and glyceraldehyde‐3‐phosphate dehydrogenase were among the major targets of oxidative stress.
Editorial: Electrophoresis 9/2004
Authors: Veenstra Timothy D. , Isaaq Haleem J.
Published: May 2004

No abstracts.
Full scale experiments for evaluating theoretical fire wall models
Authors: Clancy P. , Young S. A.
Published: May 2004

The aim of the research described in this paper was to provide experimental results for the evaluation of theoretical models for predicting the behaviour and time‐to‐failure of loadbearing and non‐loadbearing wood framed walls in fire. References for thermal and mechanical properties of wood and gypsum board are given to provide comprehensive input for the evaluation of theoretical wall models. The scope of the research involved full‐scale uninsulated cavity walls with well‐controlled clearly known conditions including initial ambient vertical load capacity for benchmarking the reduction in capacity and stiffness, rotational stiffness of supports, eccentricity of vertical load, elastic moduli of wood and gypsum board in compression, stiffness of slip between gypsum board and studs and end stud effects. The experiments were repeated and they demonstrated that the controls led to high consistency in the results despite the inherent large variability of the mechanical properties of wood. The results include temperature distributions, initial vertical load capacity, load‐deflection plots and times‐to‐failure. The results show that the temperatures in the studs are approximately uniform until all the moisture is vaporized. Thermal properties of wood will not vary significantly for consistent density, moisture content and species of wood. The main structural actions that should be modelled for different loading regimes are deduced. Copyright © 2004 John Wiley & Sons, Ltd.
High‐order accurate numerical solutions of incompressible flows with the artificial compressibility method
Authors: Ekaterinaris John A.
Published: May 2004

A high‐order accurate, finite‐difference method for the numerical solution of incompressible flows is presented. This method is based on the artificial compressibility formulation of the incompressible Navier–Stokes equations. Fourth‐ or sixth‐order accurate discretizations of the metric terms and the convective fluxes are obtained using compact, centred schemes. The viscous terms are also discretized using fourth‐order accurate, centred finite differences. Implicit time marching is performed for both steady‐state and time‐accurate numerical solutions. High‐order, spectral‐type, low‐pass, compact filters are used to regularize the numerical solution and remove spurious modes arising from unresolved scales, non‐linearities, and inaccuracies in the application of boundary conditions. The accuracy and efficiency of the proposed method is demonstrated for test problems. Copyright © 2004 John Wiley & Sons, Ltd.
Simulation of single‐ and two‐phase flows on sliding unstructured meshes using finite volume method
Authors: Basara B. , Alajbegovic A. , Beader D.
Published: May 2004

The paper presents an efficient finite volume method for unstructured grids with rotating sliding parts composed of arbitrary polyhedral elements for both single‐ and two‐phase flows. Mathematical model used in computations is based on the ensemble averaged conservation equations. These equations are solved for each phase and in case of single‐phase flow reduce to the transient Reynolds‐averaged Navier–Stokes (TRANS) equations. Transient flow induced by rotating impellers is thus resolved in time. The use of unstructured grids allows an easy and flexible meshing for the entire flow domain. Polyhedral cell volumes are created on the arbitrary mesh interface placed between rotating and static parts. Cells within the rotating parts move each time step and the new faces are created on the arbitrary interfaces only, while the rest of the domain remain ‘topologically’ unchanged. Implicit discretization scheme allows a wide range of time‐step sizes, which further reduce the computational effort. Special attention is given to the interpolation practices used for the reconstruction of the face quantities. Mass fluxes are recalculated at the beginning of each time step by using an interpolation scheme, which enhances the coupling between the pressure and velocity fields. The model has been implemented into the commercially available CFD code AVL SWIFT (AVL AST, SWIFT Manual 3.1, AVL List GmbH, Graz, Austria, 2002). Single‐phase flow in a mixing vessel stirred by a six‐bladed Rushton‐type turbine and two‐phase flow in aerated stirred vessel with the four‐blade Rushton impeller are simulated. The results are compared with the available experimental data, and good agreement is observed. The proposed algorithm is proved to be both stable and accurate for single‐phase as well as for the two‐phase flows calculations. Copyright 2004 John Wiley & Sons, Ltd.
Assessment of sex‐specific genetic and environmental effects on bone mineral density
Authors: Brown Lillian B. , Streeten Elizabeth A. , Shuldiner Alan R. , Almasy Laura A. , Peyser Patricia A. , Mitchell Braxton D.
Published: May 2004

Although it is widely accepted that genes contribute significantly to the variation in bone mineral density (BMD), the nature of the genetic contribution is poorly defined. There are large gender differences in BMD, although whether sex‐specific genetic effects influencing variation in BMD contribute to these differences is not known. To address this issue, we studied 929 subjects from large families participating in the Amish Family Osteoporosis Study. Bone mineral density was measured at the hip and spine by dual energy x‐ray absorptiometry (DXA). We used variance decomposition procedures to partition variation in BMD into genetic and environmental effects common to both sexes and to men and women separately. After accounting for covariate effects, the heritability of BMD ranged from 0.63 to 0.72 in men and 0.80 to 0.87 in women. The residual environmental variance in BMD at the spine, but not hip, was significantly higher in men than in women (P < 0.05), reflecting a greater variance in BMD due to unexplained non‐genetic factors in men. In contrast, there were no significant differences between men and women in the magnitude of the genetic variance in BMD, nor did the genetic correlation in BMD between men and women differ significantly from one. Overall, these analyses do not provide evidence for sex‐specific genetic effects, suggesting that many of the genes influencing variation in BMD should be detectable in both men and women. © 2004 Wiley‐Liss, Inc.
End‐to‐side venous anastomosis with the internal jugular vein stump: A preliminary report
Authors: Graham Brian B. , Varvares Mark A.
Published: May 2004

Background.

Failure of free flaps is frequently because of failure of the venous vascular anastomosis. A new venous anastomosis technique that uses the stump of the internal jugular vein (IJV) is described, with preliminary data on operative outcomes.

Methods.

Retrospective analysis of eight head and neck free flap operations in which a venous anastomosis to the stump of an IJV was used compared with 222 other free flap operations in the same period (1995–2001) at a single institution.

Results.

None of the eight free flaps that used venous end‐to‐side anastomoses to the stump of an IJV failed. There were 15 failures associated with the other 222 venous microvascular anastomoses (6.8%).

Conclusions.

This new technique resulted in no failures in eight operations. Advantages of this technique include avoiding creating an anastomosis under tension or requiring a saphenous vein graft and reducing pedicle torsion at the hilum of the flap. © 2004 Wiley Periodicals, Inc. Head Neck 26: 537–540, 2004
Clinical relevance of three subtypes of primary sinonasal lymphoma characterized by immunophenotypic analysis
Authors: Kim Gwi Eon , Koom Woong Sub , Yang Woo‐Ick , Lee Sang‐Wook , Keum Ki Chang , Lee Chang Geol , Suh Chang Ok , Hahn Jee Sook , Roh Jae Kyung , Kim Joo Hang
Published: May 2004

Background.

The purpose of this study was to investigate the clinical relevance of subtypes categorized by immunophenotypic analysis in primary sinonasal lymphomas.

Methods.

Eighty patients with localized non‐Hodgkin's lymphoma involving the nasal cavity and/or paranasal sinuses were divided into three subtypes on the basis of their immunohistochemical findings: (A) B‐cell lymphoma (n = 19), (B) T‐cell lymphoma (n = 27), and (C) natural killer (NK)/T‐cell lymphoma (n = 34). The clinicopathologic profiles, immunophenotypic data, patterns of treatment failure, and survival data among the three patient groups were retrospectively compared.

Results.

The nasal cavity was the predominant site of involvement in T‐cell and NK/T‐cell lymphoma, whereas sinus involvement without nasal disease was common in B‐cell lymphoma. Systemic B symptoms were frequently observed in NK/T‐cell lymphoma. Almost all patients with NK/T‐cell lymphoma showed a strong association with the Epstein‐Barr virus by in situ hybridization studies. Sixty‐five patients (81%) patients achieved complete remission after initial treatment, but 36 (55%) of these subsequently experienced treatment failure. Although there were no significant differences in locoregional failure rates among the patients of the three groups, distant failure was far more common in B‐cell or NK/T‐cell lymphoma than in T‐cell lymphoma (p = .005). Most B‐cell lymphoma cases showed a predilection for sites of systemic failure in the nodal and extranodal sites below the diaphragm, such as the paraaortic lymph nodes or the gastrointestinal (GI) tract, whereas patients with NK/T‐cell lymphoma showed an increased risk of systemic dissemination to the skin, testes, or GI tract, including the development of hemophagocytic syndrome. The 5‐year actuarial and disease‐free survival rates for all patients were 57% and 51%, respectively. Of the three subtypes of primary sinonasal lymphomas, T‐cell lymphoma seemed to carry the most favorable prognosis and NK/T‐cell lymphoma the worst. (The 5‐year actuarial survival rate was 57% for B‐cell lymphoma, 80% for T‐cell lymphoma, 37% for NK/T‐cell lymphoma; p = .02, log‐rank.) By univariate and multivariate analyses, immunophenotype was identified as the most important prognostic factor.

Conclusions.

Our data indicate that the three subtypes of primary sinonasal lymphomas classified by immunohistochemical studies exhibit different clinical profiles, different patterns of failure, and different treatment outcomes. Given these observations, it is concluded that the recognition of these distinct subsets, diagnosed on the basis of immunophenotypic study, is very important and clinically relevant in predicting their potential behavior and prognosis. © 2004 Wiley Periodicals, Inc. Head Neck 26: 584–593, 2004
Tracheal mucormycosis presented as an intraluminal soft tissue mass
Authors: Wolf Omer , Gil Ziv , Leider‐Trejo Leonor , Khafif Avi , Biderman Philippe , Fliss Dan M.
Published: May 2004

Background.

Mucormycosis is a potentially lethal disease caused by an opportunistic fungal infection. It occurs mostly in diabetic or immunosuppressed patients and usually involves the lungs or paranasal sinuses.

Methods.

We report a rare case of a patient with diabetic ketoacidosis who presented with progressive cough and dyspnea. CT of the neck and chest showed an intraluminal soft‐tissue mass extending from the first tracheal ring to the thoracic inlet, causing severe destruction of the trachea. Direct laryngoscopy and biopsy demonstrated hyphal invasion with architecture typical of invasive mucormycosis.

Results.

The patient underwent resection of the upper trachea and prolonged amphotericin B therapy and is disease free at 24 months after surgery.

Conclusions.

In patients with diabetes presenting with progressive hoarseness, dyspnea, and endobronchial mass, a fungal infection should be considered. In case of invasive tracheal mucormycosis, prompt diagnosis and early surgical resection may help improve survival. © 2004 Wiley Periodicals, Inc. Head Neck 26: 541–543, 2004
The sentinel node concept in head and neck cancer: solution for the controversies in the n0 neck?
Authors: Werner Jochen A. , Dünne Anja A. , Ramaswamy Anette , Dalchow Carsten , Behr Thomas , Moll Roland , Folz Benedikt J. , Davis R. Kim
Published: May 2004

Background.

The majority of patients with head and neck squamous cell carcinoma (HNSCC) who have a clinical N0 neck undergo neck dissection (ND) even though no lymph node metastases may be detected. With this background, our investigation critically analyzes the value of sentinel lymphadenectomy.

Methods.

Ninety patients with HNSCC, all staged with an N0 neck, underwent intraoperative 99mTc‐radiolabeled detection of up to three hot nodes (SN1–3) during elective ND and primary site resection.

Results.

Sentinel lymphadenectomy (SN1–3) detected occult metastatic spread in 20 (22%) of 90 patients, whereas failure occurred in three of 90 patients. Metastatic spread was directed to level II in the majority (66.7%) of cases. If only the SN1 had been examined, the procedure would have failed in nine (39%) of 23 patients.

Conclusion.

Sentinel lymphadenectomy correctly identified the stage of metastatic disease in 97% of patients in cases in which up to three sentinel nodes were identified. If only the lymph node with the highest tracer activity had been excised, 39% of cancer‐positive necks would have been missed. Selective ND identified metastatic disease in the additional 3% of patients. © 2004 Wiley Periodicals, Inc. Head Neck 26: 603–611, 2004
Functional outcomes of transoral laser surgery of supraglottic carcinoma compared with a transcervical approach
Authors: Cabanillas Rubén , Rodrigo Juan Pablo , Llorente Jose Luis , Suárez Vanessa , Ortega Primitivo , Suárez Carlos
Published: May 2004

Background.

Several functional advantages have been described for the transoral laser supraglottic laryngectomy as compared with open techniques. However, comparative studies have been rarely performed.

Methods.

Functional results in 26 patients treated with a transoral approach were retrospectively compared with those of a comparable series of 26 patients who underwent a transcervical approach.

Results.

The only significant differences found between the two groups were a lesser number of temporary tracheotomies and a shorter time of removal of the nasogastric tube in the laser group. No significant differences were found in the incidence of postoperative complications, hospital stay, and swallowing capacity.

Conclusions.

The rate of functional problems after transoral laser surgery did not greatly decrease compared with the rate after the conventional procedure. The mayor advantage of the transoral approach was the lower incidence of temporary tracheotomies. © 2004 Wiley Periodicals, Inc. Head Neck 26: 653–659, 2004
Enhancing the biological activity of immobilized osteopontin using a type‐1 collagen affinity coating
Authors: Martin Stephanie M. , Schwartz Jeffrey L. , Giachelli Cecilia M. , Ratner Buddy D.
Published: May 2004

The covalent attachment of biomolecules onto surfaces represents a step toward the improvement of biomaterial properties by providing relevant biological signals of interest to the cell culture or tissue environment. The chemistries involved, however, often attach proteins to the surface in a random fashion, rather than the conformation or orientation most easily recognized by cells and other proteins both in vitro and in vivo. An alternative approach is to take advantage of natural interactions to both bind and orient a biomolecule “naturally,” thereby enhancing its biological activity. Type 1 collagen has been shown to bind to osteopontin (OPN), a protein implicated in processes such as wound healing, endothelial cell survival, and angiogenesis. This study seeks to characterize, quantify, and exploit this interaction in order to present a more naturally recognized form of OPN to the environment surrounding a biomaterial. Binding of OPN to type 1 collagen was confirmed using Surface Plasmon Resonance (SPR). Radio‐iodination of OPN showed that binding to collagen was dose‐dependent and maximal in basic conditions. Principal component analysis of Time‐of‐Flight Secondary Ion Mass Spectrometry (ToF‐SIMS) data identified differences in OPN immobilized via different techniques. Adhesion of bovine aortic endothelial cells on OPN immobilized using the affinity coating was also significantly enhanced compared to controls. Investigation into the in vivo relevance of this immobilization method is currently underway. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 70A: 10–19, 2004
Application of experimental design to the formulation of glucose oxidase encapsulation by liposomes
Authors: Rodriguez‐Nogales José Manuel , Pérez‐Mateos Manuel , Dolores Busto Ma
Published: May 2004

Fractional factorial screening design and response surface methodology were applied to optimize the entrapment of glucose oxidase in liposomes by the dehydration–rehydration vesicle (DRV) method. Phosphatidylcholine from different sources, cholesterol:phosphatidylcholine (Ch:PC) and enzyme:lipid (E:L) ratios, buffer pH, sonication frequency and trehalose concentration were the parameters selected for this study. The type of phosphatidylcholine was found to be the most important factor followed by the trehalose concentration, Ch:PC ratio, sonication frequency and E:L ratio. The pH did not play an important role in the response. By treating liposomes with trehalose, as cryoprotectant, the activity of entrapped enzyme decreased by 16%. Two of the factors (cholesterol:phosphatidylcholine and enzyme:lipid ratios) were further studied in a 32 central composite design. The optimized liposomal formulation with an entrapment efficiency of 24% was obtained for egg yolk PC with Ch:PC and E:L ratios of 0.95 and 14.69, respectively, at pH 6 and applying a sonication frequency of 150 W. Copyright © 2004 Society of Chemical Industry
Length of the antibody heavy chain complementarity determining region 3 as a specificity‐determining factor
Authors: Barrios Yvelise , Jirholt Pernilla , Ohlin Mats
Published: May 2004

The antigen binding site of an antibody is made up of residues residing in six hypervariable loops of the heavy and light chains. In most cases several or all of these loops are required for the establishment of the antigen‐binding surface. Five of these loops display a limited diversity in length and sequence while the third complementarity determining region (CDR) of the heavy chain is highly different between antibodies not only with respect to sequence but also with respect to length. Its extensive diversity is a key component in the establishment of binding sites allowing for the recognition of essentially any antigen by humoral immunity. The relative importance of its sequence vs its length diversity in this context is however, not very well established. To investigate this matter further we have used an approach employing combinatorial antibody libraries and antigen‐specific selection in the search for CDRH3 length and sequence diversity compatible with a given antigen specificity, the major antigenic determinant on the tumour‐associated antigen mucin‐1. In this way we have now defined heavy chain CDR3 length as a critical parameter in the creation of an antigen‐specific binding site. We also propose that this may reflect a dependence of a particular structure of this hypervariable loop, the major carrier of diversity in the binding site, for establishment of a given specificity. Copyright © 2004 John Wiley & Sons, Ltd.
Quality control of daily meteorological data in China, 1951–2000: a new dataset
Authors: Feng Song , Hu Qi , Qian Weihong
Published: May 2004

Long‐term observational data are essential for understanding local and regional climate and climate change. These data are also important for hydrological designs and agricultural decision making. This study examined the daily meteorological data from 726 stations in China from 1951 to 2000, and developed an unprecedented climatic dataset that contains 10 daily variables: maximum and minimum surface air temperatures, mean surface air temperature, skin surface temperature, surface air relative humidity, wind speed, wind gust, sunshine duration hours, precipitation, and pan evaporation. The characteristics of the original stations' data and quality‐control methods designed and used in developing this dataset are detailed. The quality‐control procedures identified less than 0.05% of the data records as being erroneous because of typos and incorrect units, reading, or data coding. When the spatial and temporal consistency of the variables' time series were inspected, nearly 37.9% of the stations were found to have one or more variables with inconsistent changes. The sources causing the temporal inconsistency/discontinuity were evaluated, and a method was developed and applied to adjust those data segments containing inconsistent values. The resulting data series, as an alternative to the original quality‐controlled series, showed both spatially and temporally consistent trends in the occurrence frequency of extreme climate events compared with the unadjusted data series. Finally, the quality‐controlled daily data were gridded to a 1.0° × 1.0° grid system covering China after the erroneous and missing data were estimated. This new dataset opens up opportunities for analysing and understanding the climate variability and climate change in China. Copyright © 2004 Royal Meteorological Society
The impact of the alliance on the partners: A look at cause–brand alliances
Authors: Lafferty Barbara A. , Goldsmith Ronald E. , Hult G. Tomas M.
Published: May 2004

Partnering charitable causes with brands has become a common practice for many marketing programs; it is referred to strategically as cause‐related marketing. Although there is the perception that both partners benefit from the alliance, research has focused primarily on the benefits to the brand. Using Attitude Accessibility, Congruity, and Information Integration Theories, this study empirically tests a model to evaluate the impact of cause–brand alliances on subsequent attitudes toward both partners. The results of the study (n = 463) support the assumption that attitudes toward both the cause and the brand can be enhanced as a consequence of an alliance if perceptions of the alliance are favorable. Furthermore, the cause appears to benefit from the alliance to a greater extent than the brand. The study supports the notions that the fit between partners plays a pivotal role in consumer acceptance of the alliance as plausible and that familiarity with the cause moderates the effectiveness of the alliance. These results represent a necessary step in developing a theoretical model to explain the effects of a cause–brand alliance on both partners. © 2004 Wiley Periodicals, Inc.
An empirical analysis of the determinants of price tolerance
Authors: Herrmann Andreas , Huber Frank , Sivakumar K. , Wricke Martin
Published: May 2004

In the context of pricing strategies, the notion of price tolerance is an important construct for academic researchers and marketing managers. In this article, a conceptual model of factors influencing the level of price tolerance is proposed and empirically tested with the use of data collected from airline passengers. The results support most propositions of the conceptual model and offer several insights for managerial action and further academic research. © 2004 Wiley Periodicals, Inc.
Association of medically unexplained fatigue with ACE insertion/deletion polymorphism in gulf war veterans
Authors: Vladutiu Georgirene D. , Natelson Benjamin H.
Published: May 2004

Genes associated with muscle metabolism and physical endurance were evaluated for variants that may contribute to the etiology of medically unexplained severe and chronic fatigue. Subjects included 49 Gulf War veterans and 61 nonveterans with chronic fatigue syndrome (CFS) or idiopathic chronic fatigue (ICF) and 30 veterans and 45 nonveterans who served as healthy controls. Increased risk for CFS/ICF was associated with alterations of the insertion/deletion (I/D) polymorphism in the angiotensin‐converting enzyme gene within the Gulf War veteran sample only. The I allele frequency was decreased in affected versus unaffected veterans (0.15 versus 0.48; odds ratio [OR], 5.08; 95% confidence interval [CI], 1.97–13.35; P < 0.0001). Correspondingly, the II genotype was decreased fourfold in affected veterans (0.08 versus 0.35; OR = 5.87; 95% CI: 1.21–28.36; P = 0.02), and the DD genotype was increased twofold (0.78 versus 0.39; OR, 5.4; 95% CI, 1.6–18.4; P = 0.007). Veterans with the DD genotype were eight times more likely to develop CFS/ICF than were those with the II genotype (OR, 8.30; 95% CI, 1.50–56.09; P = 0.009). Muscle Nerve 30: 38–43, 2004
Processing characteristics and mechanical properties of metallocene catalyzed linear low‐density polyethylene foams for rotational molding
Authors: Archer E. , Harkin‐Jones E. , Kearns M. P. , Fatnes A‐M.
Published: May 2004

The object of this work is to assess the suitability of metallocene catalyzed linear low‐density polyethylenes for the rotational molding of foams and to link the material and processing conditions to cell morphology and part mechanical properties (flexural and compressive strength). Through adjustments to molding conditions, the significant processing and physical material parameters that optimize metallocene catalyzed linear low‐density polyethylene foam structure have been identified. The results obtained from an equivalent conventional grade of Ziegler‐Natta catalyzed linear low‐density polyethylene are used as a basis for comparison. The key findings of this study are that metallocene catalyzed LLDPE can be used in rotational foam molding to produce a foam that will perform as well as a Ziegler‐Natta catalyzed foam and that foam density is by far the most influential factor over mechanical properties of foam. Polym. Eng. Sci. 44:638–647, 2004. © 2004 Society of Plastics Engineers.
Reactive blending of functionalized polypropylene and polyamide 6: In situ polymerization and in situ compatibilization
Authors: Teng Jing , Otaigbe Joshua U. , Taylor Eric P.
Published: May 2004

Compatibilized polypropylene/polyamide 6 blends were prepared with polypropylene, ε‐caprolactam and maleic anhydride grafted polypropylene via in situ polymerization and in situ compatibilization in a batch mixer. Scanning electron microscopy and differential scanning calorimetric analysis showed that the compatibilizing effect was significantly enhanced through use of this method compared to the classic method of blending premade polymers. The optimum processing parameters were obtained for the reactive blends and the effect of maleic anhydride grafted polypropylene content, and the effect of relative weight fraction of maleic anhydride grafted polypropylene to ε‐caprolactam on the overall morphology of the blend system was investigated. It was found that the domain sizes of the polypropylene and polyamide components in the blends could be easily controlled through proper management of the polymerization and compatibilizing reactions during processing. Polym. Eng. Sci. 44:648–659, 2004. © 2004 Society of Plastics Engineers.
Rheological study of the influence of branch content on the miscibility of octene m‐LLDPE and ZN‐LLDPE in LDPE
Authors: Hussein Ibnelwaleed A. , Williams Michael C.
Published: May 2004

The influences of branch content on the miscibility of octene LLDPE made by metal‐locene catalyst (m‐LLDPE) and by Ziegler‐Natta LLDPE (ZN‐LLDPE) in LDPE were investigated with rheological methods. Dynamic and steady shear measurements were carried out in a Rheometrics Mechanical Spectrometer 800. Here, m‐LLDPEs were used to isolate interaction of molecular parameters. Blends of octene m‐LLDPE and ZN‐LLDPE with LDPE were mixed at 190°C in the presence of an adequate amount of antioxidant. The miscibilities of blends were revealed by the dependence of their measured ηo, η′ and G′ on blend composition as well as on agreement with predictions of different emulsion models. Blends of m‐LLDPE with LDPE were found to be almost miscible in the LLDPE branching range 10–30 branches/1000 C. However, immiscibility was found to develop at lower LLDPE branch contents. For ZN‐LLDPE/LDPE systems, branch content plays a significant role especially at low branch contents. The comparison of m‐LLDPE and ZN‐LLDPE systems suggest the strong influence of branch distribution (uniform and random, respectively). Palierne, Bousmina, and Scholz models fitted the loss and storage moduli data well with a value of α/R in the range 103−104 N/m2. Polym. Eng. Sci. 44:660–672, 2004. © 2004 Society of Plastics Engineers.