bluuebunny/crossref_metadata_2025 huggingface dataset:
Statistical monitoring of multivariable dynamic processes with state‐space models
Authors: Negiz Antoine , Çlinar Ali
Published: June 2004

Industrial continuous processes may have a large number of process variables and are usually operated for extended periods at fixed operating points under closed‐loop control, yielding process measurements that are autocorrelated, cross‐correlated, and collinear. A statistical process monitoring (SPM) method based on multivariate statistics and system theory is introduced to monitor the variability of such processes. The statistical model that describes the in‐control variability is based on a canonical‐variate (CV) state‐space model that is an equivalent representation of a vector autoregressive moving‐average time‐series model. The CV state variables obtained from the state‐space model are linear combinations of the past process measurements that explain the variability of the future measurements the most. Because of this distinctive feature, the CV state variables are regarded as the principal dynamic directions A T2statistic based on the CV state variables is used for developing an SPM procedure. Simple examples based on simulated data and an experimental application based on a high‐temperature short‐time milk pasteurization process illustrate advantages of the proposed SPM method.
Nitrile reaction in high‐temperature water: Kinetics and mechanism
Authors: Izzo Bill , Harrell Cynthia L. , Klein Michael T.
Published: June 2004

The reaction pathways, kinetics and mechanisms underlying the hydrolysis of aliphatic and aromatic nitriles in high‐temperature water (HTW) were investigated. The reaction products were the associated amides and carboxylic acids. Autocatalytic kinetics were observed and confirmed by experiment and analysis of the physical chemistry of the HTW reaction environment. A model incorporating two autocatalytic steps captured the observed kinetics well, and the associated optimized rate constants highlighted the key differences in the reaction chemistry of aliphatic and aromatic nitriles. The rate behavior of nitrile hydrolysis at these conditions has tangible consequences regarding optimal processing strategies.
Moisture transport in shrinking gels during saturated drying
Authors: Achanta Srinivas , Okos Martin R. , Cushman John H. , Kessler David P.
Published: June 2004

The transport of moisture in shrinking food gels during drying is studied based on a novel thermomechanical theory accounting for a structural transition in the material—from the rubbery to the galssy state—during drying. The proposed theory is applied to the drying of a model cylindrical starch–gluten gel system. The predicted drying characteristics depend on the Deborah number, a ratio of the characteristic relaxation time to the characteristic diffusion time. At low Deborah numbers, drying is Fickian. At intermediate and high Deborah numbers, however, drying is non‐Fickian, leading to an apparent mass‐transfer shutdown, which is a result of surface dryout and skin/shell formation. Based on a time‐dependent surface boundary condition, the model proposes that surface drying is not only a function of the Biot number but also a function of the “Shell” number, a ratio of the Deborah and Biot numbers. The model is verified by comparing its predictions with experimental data from drying of starch–gluten gels at 22.5 and 40°C. The model predictions agree with experimental data and capture the observed sigmoidal shape of the experimental drying curves in the saturated flow regime. The predicted moisture profiles show shell formation and growth during drying, compatible with the experimental moisture profiles from the literature.
Spread and rebound of liquid droplets upon impact on flat surfaces
Authors: Mao Ted , Kuhn David C. S. , Tran Honghi
Published: June 2004

The spread and rebound of droplets upon impact on flat surfaces at room temperature were studied over a wide range of impact velocities (0.5–6 m/s), viscosities (1–100 mPa.s), static contact angles (30–120°), droplet sizes (1.5–3.5 mm), and surface roughnesses using a fast‐shutter‐speed CCD camera. The maximum spread of a droplet upon impact depended strongly on the liquid viscosity and the impact velocity. The tendency of a droplet to deposit or to rebound is determined primarily by the liquid viscosity and the liquid/substrate static contact angle. A model more broadly applicable than existing models was developed to predict maximum spread as a function of the Reynolds number, the Weber number, and the static contact angle. Based on the conservation of energy, a rebound model is proposed that predicts the tendency to rebound as a function of maximum spread and static contact angle.

The maximum‐spread model prediction agrees to within 10% with more than 90% of the experimental data from different sources. In the current study, the rebound model successfully predicts the tendency of a droplet to rebound.
Film profiles behind liquid slugs in gas‐liquid pipe flow
Authors: Cook Martin , Behnia Masud
Published: June 2004

A comprehensive one‐dimensional fully coupled hydrodynamic treatment of the film profiles behind liquid slugs in horizontal and inclined gas‐liquid slug flow is presented. Experiments were performed in horizontal air‐water pipes 32 and 50 mm in diameter, the smaller also being inclined to an angle of 5 degrees. Time traces of film thickness were produced with the use of a wire‐probe technique. The experimental results are compared against the theory presented here, as well as previously reported hydrodynamic models. It is concluded that the film profiles calculated by the use of one‐dimen‐sional models are highly sensitive to the choice of input variables, for example, the slug translational velocity; however, good agreement is achievable provided that consistent hydrodynamic equations and correct input variables are used. It is hoped that the work presented here will influence future mechanistic models of slug flow.
Hydrogen peroxide decomposition in supercritical water
Authors: Croiset Eric , Rice Steven F. , Hanush Russell G.
Published: June 2004

This work determines the rate constant of hydrogen peroxide decomposition in supercritical water. Experiments were conducted at pressures ranging from 5.0 to 34.0 MPa and for temperatures up to 450°C. The rate of the homogeneous decomposition reaction is distinguished from the rate of the catalytic decomposition on the reactor surface by conducting experiments at different surface‐to‐volume ratios. The rate constant of H2O2 decomposition follows the expression k(s−1) = 1013.4 ± 1.2 exp[(− 180 ± 16 kJ/mol)/RT], providing a higher value than that derived from RRKM calculations. Comparison between experiments at supercritical conditions (P = 24.5 and 34.0 MPa) and experiments in high‐pressure steam (P = 5.0 and 10.0 MPa) show that the efficiency of the catalytic surface reactions decreases significantly under supercritical conditions. The rate constant just mentioned was incorporated into a methanol oxidation model and the new prediction is compared with the experimental data of Rice et al. (1996), showing a distinct improvement compared to the original prediction.
Prediction of binary diffusion coefficients of solutes in supercritical solvents
Authors: He Chao‐Hong
Published: June 2004

New correlations, based on the rough hard‐sphere theory and an extensive literature database, were developed for the determination of the binary diffusion coefficients of liquid and solid solutes in supercritical solvents. The correlations were tested to predict 107 solute‐solvent systems with good results. The input data required for the correlations are the solute molecular weight, temperature, density and the solvent basic properties (molecular weight, critical volume, and critical pressure).
Catalytic and gas–solid reactions involving HCN over limestone
Authors: Jensen Anker , Johnsson Jan Erik , Dam‐Johansen Kim
Published: June 2004

In coal‐fired combustion systems solid calcium species may be present as ash components or limestone added to the combustion chamber. In this study heterogeneous reactions involving HCN over seven different limestones were investigated in a laboratory fixed‐bed quartz reactor at 873–1,173 K. Calcined limestone is an effective catalyst for oxidation of HCN. Under conditions with complete conversion of HCN at O2 concentrations above about 5,000 ppmv the selectivity for formation of NO and N2O is 50–70% and below 5%, respectively. Nitric oxide can be reduced by HCN to N2 in the absence of O2 and to N2 and N2O in the presence of O2. At low O2 concentrations or low temperatures, HCN may react with CaO, forming calcium cyanamide, CaCN2. The selectivities for formation of NO and N2O from oxidation of CaCN2 is 20–25% for both species. The catalytic activity of limestone for oxidation of HCN decreases with increasing degree of sulfation. Simultaneously the selectivity for formation of NO decreases while tht for N2O increases. The catalytic activity of sulfated limestone in‐creases with decreasing SO2 concentration, indicating a competition between SO2 and HCN for sites on the surface. The results indicate that heterogeneous oxidation of HCN is important in calciners and fluidized‐bed combustors with limestone addition or when burning coals with an ash with a high catalytic activity.
Predicting filtration time and maximizing throughput in a pressure filter
Authors: Landman Kerry A. , White Lee R.
Published: June 2004

The modeling of pressure filtration of flocculated suspensions using compressional rheology and a knowledge of compressional yield stress Py(ϕ) and a hydraulic resistance factor r(ϕ)(ϕ is the local volume fraction of solids) is shown to yield an initial solids loading that maximizes the throughput of the filter. The optimal initial height h0 is such that the filtration time to reach a specified average volume fraction as output equals the handling time for the filter press. The maximum throughput of the press is then examined as a function of the remaining control parameters, the initial solids volume fraction ϕ0, and the applied piston pressure δP. The dependence of filtration time on ϕ0/∞00 (where ϕ∞is the volume fraction of solids at infinite time under applied pressure δP) enables the construction of a simple numerical model for the pressure filtration process, which accurately approximates predictions of the full compressional rheology model.
Distribution kinetics of radical mechanisms: Reversible polymer decomposition
Authors: Kodera Yoichi , McCoy Benjamin J.
Published: June 2004

For polymers and other homologous mixtures that span a molecular weight (MW) range, many reaction mechanisms involve the formation, addition and decomposition of free radicals. In the chain reactions of polymerization and depolymerization, radicals and polymer molecules interact by a variety of primary reactions. We postulate that these radicals and molecules can be described by continuous molecular weight distributions (MWDs). Their chemical interactions are developed from generic, reversible addition or bond scission reactions. Distribution balance equations are proposed for initiation‐termination and propagation‐depropagation reactions, such as hydrogen abstraction, disproportionation, chain cleavage, and radical coupling. A comprehensive model including all these events conforms to the special mechanisms for chain‐end depolymer‐ization and for random‐scission polymer degradation. The evolution of an MWD from initial state to final equilibrium is described by the time dependence of MW moments. Irreversible degradation or polymerization relationships are obtained as limiting cases. First‐order rate constants observed in pyrolysis and thermolysis reactions are composed of algebraic groups of primary reaction rate constants.
IMA chromatography of a cell extract: Effect of loading pH on protein purification
Authors: Patwardhan Anshuman V. , Ataai Mohammad M.
Published: June 2004

Immobilized metal ion affinity chromatography has shown promise for isolating desired proteins from host cell extracts, based on differential affinities for chelated metal ions. This article focuses on modeling the effect of loading pH on the purity and binding capacity of target proteins, during their separation from the cell extract of Escherichia coli, using immobilized copper affinity chromatography. Early chromatography experiments revealed that cellular proteins of E. coli elute in two separate peaks from an immobilized copper column under a decreasing pH step gradient. Thus, the cell extract is modeled by a mixture of two proteins, tuna heart cytochrome c and chicken egg white lysozyme. Transport and binding parameters of these proteins are evaluated over a wide pH range and used in a mathematical model of multicomponent chromatography. Target proteins are chosen such that they elute at a pH between the elution pH of cytochrome and lysozyme. Simulation results showed that decreasing the loading pH to a value between the elution pH of the weaker copper binding proteins of E. coli and that of the target protein may not only decrease the amount of E. coli proteins bound in the column but lead to a substantially higher binding capacity for the target protein.
Dynamics of foam films in constricted pores
Authors: Singh Gurmeet , Hirasaki George J. , Miller Clarence A.
Published: June 2004

Hydrodynamics of foam films in a porous medium depend strongly on the pore geometry, foam quality, foam flow rate, surfactant formulation, rheological properties of the film, and the capillary pressure in the medium. These dynamics were studied numerically by simulating the behavior of a foam film as it traverses a periodically constricted sinusoidal pore. Different regions of film behavior exist depending on its rheological properties. For a film with rigid (immobile) surfaces, the entrainment effect leads to a thickening film consistent with related phenomena such as Bretherton's (1961) analysis of a bubble moving in a capillary tube. A film with mobile surfaces, however, stretches and thins while remaining uniform in thickness and may become unstable under certain conditions. The dependence of limiting capillary pressure on the foam flow rate and rheological properties is explained quantitatively.
Synthesis and characterization of novel odd–even nylons based on eicosanedioic acid
Authors: Cui Xiaowen , Yan Deyue
Published: June 2004

A series of novel odd–even nylons based on eicosanedioic acid, including nylons 11/20, 9/20, 7/20, 5/20, and 3/20, were prepared through step‐heating melting polycondensation with various diamines, and the products were comprehensively characterized. The results of FTIR, Raman spectra, NMR, and elemental analysis confirmed that the synthesized polyamides had the expected chemical structures. The viscosity‐average molecular weights of the obtained polyamides were in the range of 6.0 × 103–1.4 × 104. The melting points of the nylons, determined by differential scanning calorimetry, changed from 167 to 194°C. Thermogravimetric analysis gave the decomposition temperatures of the obtained nylons at about 460°C, except for nylon 3/20. Furthermore, dynamic mechanical analysis (DMA) was applied to nylons 11/20, 9/20, 7/20, and 5/20. The glass‐transition temperatures, measured by DMA, ranged from 29 to 52°C. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2066–2071, 2004
Thermal and thermo‐oxidative degradation properties of poly(benzimidazole amide imide) copolymers
Authors: Wang Huei‐Hsiung , Wu Shu‐Ping
Published: June 2004

In this study, 3,3′‐dinitrobenzidine was first reacted with excess isophthaloyl chloride to form a monomer with dicarboxylic acid end groups. Two types of aromatic dianhydride, [viz., pyromellitic dianhydride (PMDA) and 3,3′,4,4′‐sulfonyldiphthalic anhydride (DSDA)] also were reacted with excess 4,4′‐diphenyl‐ methane diisocyanate (MDI) to form polyimide prepolymers terminated with isocyanate groups. The prepolymers were reacted further with the diacid monomer to form a nitro group–containing aromatic poly(amide imide) copolymers. The nitro groups in these copolymers were hydrogenated to form amine groups and cyclized at 180°C to form the poly(benzimidazole amide imide) copolymers in polyphosphoric acid (PPA), which acts as a cyclization agent. From the viscosity measurements, copolymer appeared to be a reasonably high molecular weight. From the differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) measurements it was shown that the glass transition temperature of copolymers was in the range of ∼270–322°C. The 10% weight loss temperatures were in the range of 460 ∼ 541°C in nitrogen and ∼441–529°C in air, respectively. The activated energy and the integration parameter of degradation temperature of the copolymers were evaluated with the Doyle‐Ozawa method. It indicated that these copolymers have good thermal and thermo‐oxidative stability with the increase in imide content. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2072–2081, 2004
Prospects and implications of using chromatin insulators in gene therapy and transgenesis
Authors: Recillas‐Targa Félix , Valadez‐Graham Viviana , Farrell Catherine M.
Published: June 2004

Gene therapy has emerged from the idea of inserting a wild‐type copy of a gene in order to restore the proper expression and function of a damaged gene. Initial efforts have focused on finding the proper vector and delivery method to introduce a corrected gene to the affected tissue or cell type. Even though these first attempts are clearly promising, seveal problems remain unsolved. A major problem is the influence of chromatin structure on transgene expression. To overcome chromatin‐dependent repressive transgenic states, researchers have begun to use chromatin regulatory elements to drive transgene expression. Insulators or chromatin boundaries are able to protect a transgene against chromatin position effects at their genomic integration sites, and they are able to maintain transgene expression for long periods of time. Therefore, these elements may be very useful tools in gene therapy applications for ensuring high‐level and stable expression of transgenes. BioEssays 26:796–807, 2004. © 2004 Wiley Periodicals, Inc.
A gene for speed? The evolution and function of α‐actinin‐3
Authors: MacArthur Daniel G. , North Kathryn N.
Published: June 2004

The α‐actinins are an ancient family of actin‐binding proteins that play structural and regulatory roles in cytoskeletal organisation and muscle contraction. α‐actinin‐3 is the most‐highly specialised of the four mammalian α‐actinins, with its expression restricted largely to fast glycolytic fibres in skeletal muscle. Intriguingly, a significant proportion (∼18%) of the human population is totally deficient in α‐actinin‐3 due to homozygosity for a premature stop codon polymorphism (R577X) in the ACTN3 gene. Recent work in our laboratory has revealed a strong association between R577X genotype and performance in a variety of athletic endeavours. We are currently exploring the function and evolutionary history of the ACTN3 gene and other α‐actinin family members. The α‐actinin family provides a fascinating case study in molecular evolution, illustrating phenomena such as functional redundancy in duplicate genes, the evolution of protein function, and the action of natural selection during recent human evolution. BioEssays 26:786–795, 2004. © 2004 Wiley Periodicals, Inc.
Ups and downs of tissue and planar polarity in plants
Authors: Grebe Markus
Published: June 2004

The polar orientation of cells within a tissue is an intensively studied research area in animal cells. The term planar polarity refers to the common polar arrangement of cells within the plane of an epithelium. In plants, the subcellular analysis of tissue polarity has been limited by the lack of appropriate markers. Recently, research on plant tissue polarity has come of age. Advances are based on studies of Arabidopsis patterning, cell polarity and auxin transport mutants employing the coordinated, polar localization of auxin transporters and the planar polarity of root epidermal hairs as markers. These approaches have revealed auxin transport and response, vesicular trafficking, membrane sterol and cytoskeletal requirements of tissue polarity. This review summarizes recent progress in research on vascular tissue and planar epidermal polarity in the Arabidopsis root and compares it to findings on planar polarity in animals and cell polarity in yeast. BioEssays 26:719–729, 2004. © 2004 Wiley Periodicals, Inc.
Scavenger effect of ﬂavonols on HOCl‐induced luminol chemiluminescence
Authors: Selloum Laïd , Djelili Hanifa , Sebihi Laïla , Arnhold Juergen
Published: June 2004

Hypochlorous acid (HOCl), the main product of the myeloperoxidase system, is a strong oxidant and a potent chlorinating agent, which can damage host tissues. In the present work, the scavenger effect of three aglycone ﬂavonols (myricetin, quercetin and kaempferol) and of the natural glycoside ﬂavonol, rutin, was studied towards HOCl using luminol‐dependent chemiluminescence (CL). At 1 µmol/L ﬁnal concentration, rutin was the most powerful scavenger of HOCl with an inhibitory luminol oxidation of 91.4% ± 3.2%. Quercetin, kaempferol and myricetin inhibited the luminol‐dependent CL at the same concentration only by 75.9% ± 3.4%, 57.7% ± 5.3% and 43.3% ± 3.5%, respectively. With increasing concentration of these ﬂavonols, a dose‐dependent inhibition of luminol CL was observed. In order to prove to what extent ﬂavonols scavenge HOCl, their concentrations that gave 50% inhibition of luminescence (IC50) were compared to IC50 values of the sulphur‐containing compounds N‐acetyl cysteine (NAC) and taurine. The scavenging activities of compounds tested decrease in the order: rutin > NAC > quercetin > kaempferol > taurine. The present study revealed that rutin was the most effective scavenger agent. Copyright © 2004 John Wiley & Sons, Ltd.
Determination of quercetin in human plasma after ingestion of commercial canned green tea by semi‐micro HPLC with electrochemical detection
Authors: Jin Dongri , Hakamata Hideki , Takahashi Kouji , Kotani Akira , Kusu Fumiyo
Published: June 2004

Determination of quercetin in human plasma was carried out by semi‐micro high‐performance liquid chromatography with electrochemical detection. Peak heights for quercetin were found to be linearly related to the amount of each quercetin injected from 1.5 to 750 pg. The detection limit (signal‐noise ratio, S/N = 3) of the present method for quercetin was 0.3 pg. Glucuronic and sulfate forms of quercetin in plasma were hydrolyzed enzymatically using β‐glucuronidase and sulfatase, respectively. Quercetin in plasma and the hydrolyzed solution were extracted with ethyl acetate and determined by the present method. The time courses of concentrations of quercetin in human plasma showed maxima at 1–1.5 h after ingestion of 340 mL of commercial canned green tea. Copyright © 2004 John Wiley & Sons, Ltd.
The effects of Maras powder (smokeless tobacco) on oxidative stress in users
Authors: Kilinc Metin , Okur Erdogan , Kurutas Ergul Belge , Guler Fatma Inanc , Yildirim Ilhami
Published: June 2004

Maras Powder (MP) is a special kind of smokeless tobacco widely used in the southeast region of Turkey especially in Kahramanmaras and Gaziantep and other southeastern cities. It is obtained from a tobacco species, Nicotiana rustica L and ash of oak or grapevine wood. Tobacco may increase oxidative stress, which is related to the products of the oxygen metabolism taking place in all cells. Cellular antioxidants, e.g. catalase (CAT), superoxide dismutase (SOD) and glucose 6‐phosphate dehydrogenase (G6PD) protect the cell against oxidative damage. An imbalance between the ROS and antioxidants in favour of ROS is described as oxidative stress. In this study, we aimed to investigate the effect of MP on antioxidant enzyme levels and lipid peroxidation. We measured malondialdehyde (MDA), CAT, SOD and G6PD levels in blood of 68 MP users and 30 healthy controls who did not use MP. CAT, SOD and G6PD levels were lower in MP users than in the controls. On the other hand, lipid peroxidation levels (MDA), one of the best indicators of cytological damage, was increased in MP users compared with the controls. The present study showed that MP increases oxidative stress, which may cause many systemic disorders, including arteriosclerosis. Copyright © 2004 John Wiley & Sons, Ltd.
TNF‐α and leptin in experimental liver fibrosis models induced by carbon tetrachloride and by common bile duct ligation
Authors: Bahçecıoğlu İbrahim Halil , Yalniz Mehmet , Ataseven Hüseyin , Bülbüller Nurullah , Keçecı Muzaffer , Demırdağ Kutbeddin , Özercan İbrahim , Üstündağ Bilal
Published: June 2004

In this study we investigated TNF‐α and leptin levels in two different liver fibrosis models induced by carbon tetrachloride (CCl4) and common bile duct ligation (CBDL). A total of 36 male rats of Albino‐Wistar strain were allocated to three groups. One of the groups was the control. The second group received 0.15 ml 100 g−1 CCl4 subcutaneously for 6 weeks, 3 days per week. The third group underwent common bile duct ligation (CBDL) and was monitored for 4 weeks. Histopathological investigation included fibrosis, steatosis and inflammation. Serum IL‐6 and TNF‐α levels were analysed by ELISA methods and leptin was analysed by RIA. Fibrosis and steatosis increased significantly in the CCl4 group in comparison with the CBDL group (p < 0.01; p < 0.001). Leptin and TNF‐α levels in CCl4 group were higher than those in the CBDL and control groups (p < 0.05). TNF‐α and leptin levels were not related to each another in either the CCl4 group or the CBDL group (r=0.22, p > 0.05; r=0.19, p > 0.05). The IL‐6 level was higher in the CCl4 group in relation to severity of inflammation (p < 0.05). TNF‐α and leptin levels were higher in animals with liver fibrosis induced by CCl4, than they were in those whose liver fibrosis was induced by common bile duct ligation. Leptin and TNF‐α may be less effective on the development of liver fibrosis in the group which underwent common bile duct ligation. Copyright © 2004 John Wiley & Sons, Ltd.
Short‐ and long‐term clinical outcome after various stent implantation: Overview of the results of uni‐ and multicenter stent registries
Authors: Gyöngyösi Mariann , Khorsand Aliashgar , Sperker Wolfgang , Strehblow Christoph , Wexberg Paul , Probst Peter , Siostrzonek Peter , Lang Irene , Sochor Heinz , Glogar Dietmar
Published: June 2004

The present study reports the results of the short‐ and long‐term outcomes of prospective uni‐ and multicenter stent registries: Palmaz‐Schatz (n = 140 patients), Ave‐Micro and GFX (n = 280), Multilink Duet (n = 340), Multilink Tetra (n = 192), and Carbo (n = 140) Stent Registries, as well as the predictors and angiographic cutoff points predicting major adverse cardiac events (MACE) after different stent implantations. Significant decrease in subacute stent thrombosis (from 2.9% to 0) and MACE (from 35% to 8.3%) occurred as the improved stents, optimized stent implantation technique, and new postintervention drug therapy were introduced. The changes of angiographic cutoff values (postintervention minimal lumen diameter and preintervention reference diameter: from 2.9 and 3.1 mm for Palmaz‐Schatz to 2.5 and 2.8 mm for Multilink Duet, Multilink Tetra, and Carbo stents) and clinical and angiographic factors predicting MACE indicated the change of traditional restenosis paradigm and that progress in clinical practice might be able to counterbalance unfavorable lesion and intervention‐related characteristics. Catheter Cardiovasc Interv 2004;62:331–338. © 2004 Wiley‐Liss, Inc.
Outcomes for overlapping stents in the extracranial carotid artery
Authors: Lesley Walter S. , Weigele John B. , Chaloupka John C.
Published: June 2004

Various diseases of the carotid artery are treatable by stenting. However, few reports of overlapping carotid stents exist. As a result, the indications, long‐term outcomes, and potential complications of this technique remain largely unknown. We therefore present and examine a series of 11 patients treated by this unique stenting method. A retrospective single‐institution review was performed for patients in whom overlapping carotid stents were placed. Only patients with imaging follow‐up beyond 3 months were included. Of 38 patients who had extracranial carotid artery stents placed, 11 patients fulfilled the inclusion criteria for both overlapping stents and imaging follow‐up greater than 3 months (range, 0.4–3 years; mean, 1.3 years). Clinical follow‐up ranged between 0.4 and 3.6 years (mean, 2.1 years). Carotid pathology within this cohort included atheromatous stenosis (n = 3), recurrent stenosis following carotid endarterectomy (n = 2) or stenting (n = 1), postirradiation angiitis (n = 1), carotid artery kink created by initial stent placement (n = 2), and both traumatic (n = 1) and neoplastic (n = 1) carotid blowout syndrome. No permanent stroke or stenting‐related death occurred. Focal stenosis or intimal hyperplasia resulting in 35% or less luminal narrowing developed in three patients (27%) after tandem stenting. Overlapping stents provide a durable treatment for a variety of extracranial carotid pathologies. Clinically and hemodynamically significant (> 50%) poststenting stenosis or intimal hyperplasia did not occur in this series. Catheter Cardiovasc Interv 2004;62:375–379. © 2004 Wiley‐Liss, Inc.
Hepatocellular carcinoma and liver tumors in South African children
Authors: Moore Samuel W. , Millar Alistair J. W. , Hadley G. P. (Larry) , Ionescu Gabriel , Kruger Mariana , Poole Janet , Stones David , Wainwright Linda , Chitnis Milind , Wessels Glynn
Published: June 2004

BACKGROUND

The high regional incidence of hepatocellular carcinoma (HCC) in South Africa also may be present in children of the region, although the link to hepatitis B (HBV) appears less clear. The objective of this study was to assess the incidence and probable causes of HCC in South African children.

METHODS

Data were obtained from seven participating pediatric oncology units and from the tumor registry to review hepatic tumors in children in South Africa.

RESULTS

One hundred ninety‐four children (ages 0–14 years) presented with malignant primary hepatic tumors (1988–2003). One hundred twelve tumors (57%) were hepatoblastoma (HB), 68 tumors (35%) were hepatocellular carcinoma (HCC) (including 9 patients with the fibrolamellar variant, 6 of which occurred in black children), 10 tumors (5%) were sarcoma of the liver, and 4 tumors were lymphoma. The ratio of HB to HCC (1.67) was markedly lower compared with other reports, suggesting a greater prevalence of HCC. Correlation with population statistics indicated an incidence of 1.066 malignant liver tumors per year per 106 children age < 14 years (HB, 0.61 per 106 children; HCC, 0.39 per 106). Two‐thirds of patients with HCC were positive for HBV surface antigen (HBsAg), and HCC occurred mostly in black African patients (93%). The mean age of onset was 1.47 years for HB and 10.48 years for HCC. A preponderance of males (3.5:1.0) was noted in the HBsAg‐positive group that was not reflected elsewhere. Serum α‐fetoprotein (AFP) levels were raised both in patients with HB (100%; most AFP levels were very high) and in patients with HCC (69%), although 15% of patients with HCC had low or normal AFP levels.

CONCLUSIONS

It appeared from the current results that HCC is more prevalent among children in South Africa compared with the children in more developed countries, although their rates were lower that the rates noted in adults. A collaborative approach will be required to improve their diagnosis and management. Cancer 2004. © 2004 American Cancer Society.
Statistics of single‐molecule measurements: Applications in flow‐cytometry sizing of DNA fragments
Authors: Ferris Matthew M. , Habbersett Robbert C. , Wolinsky Murray , Jett James H. , Yoshida Thomas M. , Keller Richard A.
Published: June 2004

Background

The measurement of physical properties from single molecules has been demonstrated. However, the majority of single‐molecule studies report values based on relatively large data sets (e.g., N > 50). While there are studies that report physical quantities based on small sample sets, there has not been a detailed statistical analysis relating sample size to the reliability of derived parameters.

Methods

Monte Carlo simulations and multinomial analysis, dependent on quantifiable experimental parameters, were used to determine the minimum number of single‐molecule measurements required to produce an accurate estimate of a population mean. Simulation results were applied to the fluorescence‐based sizing of DNA fragments by ultrasensitive flow cytometry (FCM).

Results

Our simulations show, for an analytical technique with a 10% CV, that the average of as few as five single‐molecule measurements would provide a mean value within one SD of the population mean. Additional simulations determined the number of measurements required to obtain the desired number of replicates for each subpopulation within a mixture. Application of these results to flow cytometry data for λ/HindIII and S. aureus Mu50/SmaI DNA digests produced accurate DNA fingerprints from as few as 98 single‐molecule measurements.

Conclusions

A surprisingly small number of single‐molecule measurements are required to obtain a mean measurement descriptive of a normally‐distributed parent population. © 2004 Wiley‐Liss, Inc.
Bewehrtes Mauerwerk nach dem überarbeiteten Eurocode 6, Teil 1‐1
Authors: Jäger Wolfram , Baier Gunar , Schöps Peter
Published: June 2004

Mit dem überarbeiteten Eurocode 6, Teil 1‐1 liegt eine europäische Norm vor, die zukünftig eine sehr einfache Bemessung von bewehrtem Mauerwerk gestatten wird und die einige der strengen Restriktionen der DIN 1053‐3 aufhebt. Sie schafft damit Voraussetzungen für eine breitere Anwendung des bewehrten Mauerwerks auch in Deutschland.

Die wesentlichen Formeln der Norm sind auf ihre Hintergründe und Brauchbarkeit hin überprüft worden. Die getroffenen Vereinfachungen und erzielten Kompromisse sind bekannt. Es ist damit eine Grundlage für die Festlegung des nationalen Sicherheitsniveaus im Rahmen der Ausarbeitung des Nationalen Anhangs zu dieser Norm vorhanden.
‘Lipoproteins, glycoxidation and diabetic angiopathy’
Authors: Jenkins Alicia J. , Best James D. , Klein Richard L. , Lyons Timothy J.
Published: June 2004

The chronic vascular complications of diabetes (nephropathy, retinopathy and accelerated atherosclerosis) are a major cause of morbidity and premature mortality. In spite of the more widespread availability of intensive diabetes management, approximately one in three people with diabetes develop aggressive complications and over 70% die of atherosclerosis‐related diseases. Genetic and acquired factors are likely to be contributory. Potential mediators of vascular damage may include the interrelated processes of lipoprotein abnormalities, glycation, oxidation and endothelial dysfunction. Lipoprotein abnormalities encompass alterations in lipid concentrations, lipoprotein composition and subclass distribution and lipoprotein‐related enzymes. Nonenzymatic glycation and oxidative damage to lipoproteins, other proteins and to vascular structures may also be deleterious. As atherosclerosis is a chronic condition commencing in youth, and because clinical events may be silent in diabetes, surrogate measures of vascular disease are important for early identification of diabetic patients with or at high risk of vascular damage, and for monitoring efficacy of interventions. The increasing array of biochemical assays for markers and mediators of vascular damage, noninvasive measures of vascular health, and therapeutic options should enable a reduction in the excessive personal and economic burden of vascular disease in type 1 and type 2 diabetes. Copyright © 2004 John Wiley & Sons, Ltd.
Diverse populations of T cells with NK cell receptors accumulate in the human intestine in health and in colorectal cancer
Authors: O'Keeffe Joan , Doherty Derek G. , Kenna Tony , Sheahan Kieran , O'Donoghue Diarmuid P. , Hyland John M. , O'Farrelly Cliona
Published: June 2004

T cells expressing NK cell receptors (NKR) display rapid MHC‐unrestricted cytotoxicity and potent cytokine secretion and are thought to play roles in immunity against tumors. We have quantified and characterized NKR+ T cells freshly isolated from epithelial and lamina propria layers of duodenum and colon from 16 individuals with no evidence of gastrointestinal disease and from tumor and uninvolved tissue from 19 patients with colorectal cancer. NKR+ T cell subpopulations were differentially distributed in different intestinal compartments, and CD161+ T cells accounted for over one half of T cells at all locations tested. Most intestinal CD161+ T cells expressed α β TCR and either CD4 or CD8. Significant proportions expressed HLA‐DR,CD69 and Fas ligand. Upon stimulation in vitro, CD161+ T cells produced IFN‐γ and TNF‐α but not IL‐4. NKT cells expressing the Vα24Vβ11 TCR, which recognizes CD1d,were virtually absent from the intestine, but colonic cells produced IFN‐γ in response to the NKT cell agonist ligand α‐galactosylceramide. NKR+ T cells were not expanded in colonic tumors compared to adjacent uninvolved tissue. The predominance, heterogeneity and differential distribution of NKR+ T cells at different intestinal locations suggests that they are central to intestinal immunity.
Phosphane‐Catalyzed Reactions of LAlH2 with Elemental Chalcogens; Preparation of [LAl(μ‐E)2AlL] [E = S, Se, Te, L = HC{C(Me)N(Ar)}2, Ar = 2,6‐iPr2C6H3]
Authors: Jancik Vojtech , Moya Cabrera Monica M. , Roesky Herbert W. , Herbst‐Irmer Regine , Neculai Dante , Neculai Ana M. , Noltemeyer Mathias , Schmidt Hans‐Georg
Published: June 2004

Addition of catalytic amounts of a phosphane to a reaction mixture containing LAlH2 [2; L = HC{C(Me)N(Ar)}2, Ar = 2,6‐iPr2C6H3] and elemental Se or Te resulted in the formation of poorly soluble [LAl(μ‐Se)2AlL] (3) and [LAl(μ‐Te)2AlL] (4), respectively. The sulfur analogue [LAl(μ‐S)2AlL] (5) could not be obtained from the direct reaction of 2 with elemental sulfur; consequently, its synthesis was successfully achieved from the reaction of [LAlH2] and [LAl(SH)2]. A possible mechanism for the formation of [LAl(μ‐Se)2AlL] and [LAl(μ‐Te)2AlL] is discussed. The molecular structures of compounds 3−5 were determined by X‐ray structure analyses. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Interaction of the [GaH4]− Anion with Weak XH Acids − A Spectroscopic and Theoretical Study
Authors: Belkova Natalia V. , Filippov Oleg A. , Filin Andrey M. , Teplitskaya Liliya N. , Shmyrova Yulia V. , Gavrilenko Vyacheslav V. , Golubinskaya Ludmila M. , Bregadze Vladimir I. , Epstein Lina M. , Shubina Elena S.
Published: June 2004

The dihydrogen bonding (DHB) between the hydride atom of the [Bu4N][GaH4] salt and different XH acids, namely CF3CH2OH, FCH2CH2OH, iPrOH, MeOH, indole and 4‐O2NC6H4NH2, has been investigated for the first time by low‐temperature IR spectroscopy. The DHB spectroscopic and thermodynamic parameters in solvents of low polarity and high basicity (Ej = 1.37) were obtained. The nature, structures, energies and electron distributions of the model DHB complexes of GaH4− with H2O, MeOH, CF3OH, H2NCF3 or NO2C6H4NH2 were studied by DFT calculations and compared with those of the analogous complexes of BH4− with H2O, MeOH or CF3OH. Two types of DHB structures with monodentate and symmetric chelate coordination were found. The lengthening of the X−H and Ga−H bonds, electron polarization and overlap population of the H···H bond are greater in the first type of structure. A comparative analysis of experimental data demonstrates that the spectroscopic and thermodynamic characteristics, e.g. ν(XH) and ν(GaH) band shifts, ν(XH)bonded integral intensities, formation enthalpies and Ej of all the DHB complexes increase down the group (BH4−·HX < GaH4−·HX). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Relationships between exercise behaviour, eating‐disordered behaviour and quality of life in a community sample of women: when is exercise ‘excessive’?
Authors: Mond J. M. , Hay P. J. , Rodgers B. , Owen C. , Beumont P. J. V.
Published: June 2004

Objective

To examine relationships between exercise behaviour, eating‐disordered behaviour and quality of life in a community sample of women.

Method

Self‐report measures of frequency of exercise, obligatoriness of exercise and motivation for exercise, and of eating disorder psychopathology and quality of life, were completed by 169 women aged 18–45 who engaged in regular exercise.

Results

Exercising to improve appearance or body tone, and feelings of guilt following the postponement of exercise, were the exercise variables most strongly associated with elevated levels of eating disorder psychopathology and, in turn, reduced quality of life. There was no association between exercise behaviour and quality of life independent of the effects of eating disorder psychopathology.

Conclusions

Operational definitions of ‘excessive exercise’ might usefully include reference to the use of exercise to improve appearance or body tone and the experience of guilt following postponement of exercise. Inclusion of such information in prevention programmes for eating disorders may also be of benefit. ‘Excessive exercise’ is unlikely to be associated with impairment in psychosocial functioning in the absence of eating disorder psychopathology. Copyright © 2004 John Wiley & Sons, Ltd and Eating Disorders Association.
Chemical composition of the essential oils from fruits, leaves and ﬂowers of the Amur cork tree (Phellodendron amurense Rupr.)
Authors: Lis Anna , Boczek Ewa , Góra Józef
Published: June 2004

The essential oils from fruits, leaves and ﬂowers of the Amur cork tree (Phellodendron amurense Rupr.) were analysed by GC, GC–MS and 1H‐NMR spectroscopy. About 80 compounds were identiﬁed in each oil. Myrcene (62.3–70.3%) and β‐caryophyllene (6.8–10.5%) dominated in the oils from unripe and ripe fruits. The leaf oil contained β‐elemol (18.5%) and (Z)‐β‐ocimene (12.6%) as the main constituents, whereas in the ﬂower oil these were (Z)‐β‐ocimene (9.5%), β‐elemol (9.4%), myrcene (7.8%) and nonacosane (7.7%). Copyright © 2004 John Wiley & Sons, Ltd.
A stabilized finite element method for the Stokes problem based on polynomial pressure projections
Authors: Dohrmann Clark R. , Bochev Pavel B.
Published: June 2004

A new stabilized finite element method for the Stokes problem is presented. The method is obtained by modification of the mixed variational equation by using local L2 polynomial pressure projections. Our stabilization approach is motivated by the inherent inconsistency of equal‐order approximations for the Stokes equations, which leads to an unstable mixed finite element method. Application of pressure projections in conjunction with minimization of the pressure–velocity mismatch eliminates this inconsistency and leads to a stable variational formulation.

Unlike other stabilization methods, the present approach does not require specification of a stabilization parameter or calculation of higher‐order derivatives, and always leads to a symmetric linear system. The new method can be implemented at the element level and for affine families of finite elements on simplicial grids it reduces to a simple modification of the weak continuity equation. Numerical results are presented for a variety of equal‐order continuous velocity and pressure elements in two and three dimensions. Copyright © 2004 John Wiley & Sons, Ltd.
Shoulder and neck morbidity in quality of life after surgery for head and neck cancer
Authors: van Wilgen C. P. , Dijkstra P. U. , van der Laan B. F. A. M. , Plukker J. Th. , Roodenburg J. L. N.
Published: June 2004

Background.

Quality of life has become a major issue in determining the outcome of treatment in head and neck surgery with curative intent. The aim of our study was to determine which factors in the postoperative care, especially shoulder and neck morbidity, are related to quality of life and how these outcomes compared between patients who had undergone surgery and a control group.

Methods.

We analyzed physical symptoms, psychological symptoms, and social and functional well‐being at least 1 year after surgery and evaluated the differences in quality of life between patients who had undergone head and neck surgery and a control group.

Results.

Depression scores contributed significantly to all domains of quality of life. Reduced shoulder abduction, shoulder pain, and neck pain are related to several domains of quality of life. The patient group scored significantly worse for social functioning and limitations from physical problems but scored significantly better for bodily pain and health changes.

Conclusion.

Depression and shoulder and neck morbidity are important factors in quality of life for patients who have undergone surgery for head and neck cancer. © 2004 Wiley Periodicals, Inc. Head Neck 26: 839–844, 2004
Suppressing effects of dietary supplementation of soybean trypsin inhibitor on spontaneous, experimental and peritoneal disseminated metastasis in mouse model
Authors: Kobayashi Hiroshi , Fukuda Yoichi , Yoshida Ryuji , Kanada Yasufumi , Nishiyama Setsuko , Suzuki Mika , Kanayama Naohiro , Terao Toshihiko
Published: June 2004

The modifying effects of a Kunitz trypsin inhibitor (KTI) and a Bowman‐Birk trypsin inhibitor (BBI), purified from soybean trypsin inhibitor, as dietary supplements on experimental and spontaneous pulmonary metastasis of murine Lewis lung carcinoma 3LL cells as well as peritoneal disseminated metastasis model in human ovarian cancer HRA cells were investigated in i.v., s.c. and i.p. injection models in mice. Seven groups of female C57BL/6 or nude mice were fed a basal diet (control group) or the basal diet supplemented with KTI or BBI (5, 15, or 50 g/kg). Here we show that, in an in vivo spontaneous metastasis assay, the diet supplementation with KTI (15 and 50 g/kg), but not with BBI, for 28 days immediately after s.c. tumor cell inoculation significantly inhibited the formation of lung metastasis in C57BL/6 mice in a dose‐dependent manner. The inhibition of lung metastasis was not due to direct antitumor effects of KTI. In an in vivo experimental metastasis assay, the diet supplementation with KTI or BBI for 21 days after i.v. tumor cell inoculation did not reduce the number of lung tumor colonies. In addition, KTI (15 or 50 g/kg) treatment in a peritoneal disseminated metastasis model of HRA cells resulted in a 40% reduction in total tumor burden when compared with control animals. Immunoblot analysis revealed that KTI specifically reduced expression of uPA protein as well as phosphorylation of MAP kinase and PI3 kinase proteins in the cells stimulated with agonists (G‐CSF for 3LL cells or TGF‐β1 for HRA cells). These results suggest that dietary supplementation of KTI more efficiently regulates the mechanism involved in the entry into vascular circulation of tumor cells (intravasation) than in extravasation during the metastatic process. KTI treatment may also be beneficial for ovarian cancer patients with or at risk for peritoneal disseminated metastasis; it greatly reduces tumor burden in part by inhibiting phosphorylation of MAP kinase and PI3 kinase, leading to suppression of uPA expression. © 2004 Wiley‐Liss, Inc.