bluuebunny/crossref_metadata_2025 huggingface dataset:
Three‐month, zero‐order piroxicam release from monodispersed double‐walled microspheres of controlled shell thickness
Authors: Berkland Cory , Cox Amanda , Kim Kyekyoon (Kevin) , Pack Daniel W.
Published: July 2004

Double‐walled microspheres represent an increasingly important class of drug delivery devices that provide enhanced control of drug delivery schedules. Clearly, the overall particle size and shell thickness are important parameters in modulating the drug release rates. Precision particle fabrication technology has been used to fabricate double‐walled microspheres of predefined uniform diameters of 40–60 μm exhibiting a poly(D,L‐lactide‐co‐glycolide) (PLG) core and poly(L‐lactide) (PL) shell of controllable thickness from ∼2 to 10 μm. The release of a model small‐molecule drug, piroxicam, from uniform microspheres of pure PLG and PL is compared to the release from double‐walled microspheres exhibiting different PL shell thicknesses. The presence of the PL shell enveloping a PLG core essentially eliminated the initial “burst” of piroxicam that was observed when the drug was released from pure PLG microspheres. In addition, increasing the PL shell thickness shifted the release profile from a biphasic shape for pure PLG microspheres to zero‐order piroxicam release over 3 months for the thickest (∼10 μm) PL shell. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 70A: 576–584, 2004
In vitro response of osteoblast‐like and odontoblast‐like cells to unsubstituted and substituted apatites
Authors: Inoue Miho , LeGeros Racquel Z. , Inoue Masahisa , Tsujigiwa Hidetsugu , Nagatsuka Hitoshi , Yamamoto Toshio , Nagai Noriyuki
Published: July 2004

Different types of calcium phosphate compounds [calcium‐deficient apatite (CDA); beta‐tricalcium phosphate (β‐TCP); biphasic calcium phosphate (BCP)] are commercially available for medical and dental applications as bone substitute materials. Most of the reported in vitro studies on cell‐material interactions have used osteoblast‐like cells. The purpose of this study was to investigate the in vitro response of osteoblast‐like (MC3T3‐E1) and odontoblast‐like (MDPC23) cells on unsubstituted (HA) and substituted (F‐substituted) apatites. MC3T3‐E1 and MDPC23 were cultured in alpha‐modified medium containing 10% fetal bovine serum, ascorbic acid (50 μg/mL) and β‐glycerophosphate (2 mM). The cells were seeded on pellets made from HA, and FAp (with low, medium, and high F concentrations). Cell morphology was observed after 7 and 14 days using scanning electron microscopy (SEM). Cell attachment and differentiation were determined from the DNA content, alkaline phosphatase (ALP) activity, and total collagen content. Pellet surface composition was characterized by using Fourier Transform infrared spectroscopy. MC3T3‐E1 and MDPC23 cells on HA were normal in shape and in fusion but not on FAp. Results of this study showed that the pattern of cell proliferation of osteoblast‐like cells was different from that of the odontoblast‐like cells. This study suggests that cell morphology, fusion, and proliferation on biomaterial surfaces depend on cell type (osteoblast‐like vs odontoblast‐like cell) and biomaterial composition (unsubstituted vs substituted F‐apatites). © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 70A: 585–593, 2004
Restoration of function after spinal cord transection using a collagen bridge
Authors: Yoshii Satoru , Oka Masanori , Shima Mitsuhiro , Taniguchi Ataru , Taki Yoshiro , Akagi Masao
Published: July 2004

The restoration of function of transected adult mammalian spinal cord without living tissue has not been reported previously. We report the first success of functional restoration of transected spinal cord without living tissue. We grafted collagen filaments parallel or transverse to the axis of the spinal cord to bridge 5‐mm defects of 47 adult rat spinal cords. Twenty‐five rats were used as a control. Of the 72 rats, 42 rats survived the experimental period. At 4 weeks postoperatively, regenerated axons crossed the proximal and distal spinal cord‐implant interfaces in all 5 rats of the parallel‐grafted group. At 12 weeks postoperatively, the rats in the parallel‐grafted group (8 rats) could walk, run, and climb with hind‐forelimb coordination. The somatosensory‐evoked potentials were seen. Results suggest that the collagen filaments support the axonal regeneration of the transected spinal cord and the restoration of function when grafted parallel to the axis of the spinal cord. The functional restoration appeared to be permanent, raising the possibility of therapeutic application in humans. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 70A: 569–575, 2004
Cover Picture: Macromol. Rapid Commun. 15/2004
Authors: Hiroi Ryoichi , Ray Suprakas Sinha , Okamoto Masami , Shiroi Takashi
Published: July 2004

Cover: The structure of pristine protonated layered titanate (HTO) (left) and the bright‐field transmission electron microscopy image of a photodegradable nanocomposite (right) prepared by melt extrusion of polylactide and organically modified HTO are shown on the cover.

Further details can be found in the Communication by R. Hiroi, S. S. Ray, M. Okamoto,* and T. Shiroi on page 1359.
Association of a mutation in the ryanodine receptor 1 gene with equine malignant hyperthermia
Authors: Aleman Monica , Riehl Joyce , Aldridge Brian M. , Lecouteur Richard A. , Stott Jeffrey L. , Pessah Isaac N.
Published: July 2004

Equine malignant hyperthermia (MH) has been suspected but never genetically confirmed. In this study, we investigated whether mutations in a candidate gene,RyR1, were associated with MH in two clinically affected horses.RyR1gene sequences revealed polymorphisms in exons 15, 17, and 46 inWTRyR1 andMHRyR1 horses with one derived amino acid change inMHRyR1 exon 46, R2454G. TheMHRyR1 horses were genetically heterozygous for this mutation, but presented an MH phenotype with halothane challenge. Skeletal sarcoplasmic reticulum from a R2454G heterozygote collected during a fulminant MH episode showed significantly higher affinity and density of [3H]ryanodine‐binding sites compared toWTRyR1, but no differences in Ca2+, Mg2+, and caffeine modulation. In conclusion, an autosomal missense mutation inRyR1is associated with MH in the horse, providing a screening test for susceptible individuals. [3H]ryanodine‐binding analysis suggests that long‐lasting changes in RyR1 conformation persists in vitro after the triggering event. Muscle Nerve 30: 356–365, 2004
Cardinality constrained path covering problems in grid graphs
Authors: Apollonio N. , Caccetta L. , Simeone B.
Published: July 2004

In this article we continue our study on the complexity of Path Covering Problems started in 2. Here, taking one further step, we investigate the complexity of the problem on grids. For special classes of grids (general grids, grids with a fixed number of rows, ladders), and several special unweighted path collections (general paths, paths of length 2, L‐shaped paths, pipes, hooks, staples) we either give polynomial‐time algorithms or prove NP‐completeness results. © 2004 Wiley Periodicals, Inc. NETWORKS, Vol. 44(2), 120–131 2004
A competitive scheduling problem and its relevance to UMTS channel assignment
Authors: Arbib Claudio , Smriglio Stefano , Servilio Mara
Published: July 2004

This article investigates a two‐user competitive scheduling problem. The problem arises in a Universal Mobile Telecommunication System (UMTS) developed within the European IST project FUTURE: given two mobile terminals, one wants to maximize the on‐time data packets transmitted to one user, while guaranteeing a certain amount of on‐time data packets to the other. We show that the problem is NP‐hard, despite peculiar properties of data and solutions. We propose a fast lagrangian heuristic able to cope with a severe real‐time requirement, and compare it to a greedy‐like heuristic on a set of practical instances. © 2004 Wiley Periodicals, Inc. NETWORKS, Vol. 44(2), 132–141 2004
Decomposition techniques for the minimum toll revenue problem
Authors: Bai Lihui , Hearn Donald W. , Lawphongpanich Siriphong
Published: July 2004

The objective of the minimum toll revenue (MINREV) problem is to find tolls that simultaneously cause users to use the transportation network efficiently and minimize the total toll revenues that must be collected. This article investigates the Dantzig‐Wolfe (DW) decomposition as an approach for solving the MINREV problem and establishes its relationships with a cutting plane algorithm and other proposed approaches. The article also identifies the variant of DW decomposition most suitable for implementation. Numerical experiments with real transportation networks suggest that DW decomposition is robust and should be used when the problems are too large for standard linear programming software. Although transportation planning is the application emphasized in this article, it should be noted that the MINREV problem also has applications in telecommunication network design and control. © 2004 Wiley Periodicals, Inc. NETWORKS, Vol. 44(2), 142–150 2004
An implicit enumeration scheme for the batch selection problem
Authors: Agnetis A. , Rossi F. , Smriglio S.
Published: July 2004

An important problem arising in the management of logistic networks is the following: given a set of activities to be performed, each requiring a set of resources, select the optimal set of resources compatible with the system capacity constraints. This problem is called Batch Selection Problem (BSP) from traditional applications to flexible manufacturing. BSP is known to be NP‐hard, and is also considered a difficult integer programming problem. In fact, polyhedral approaches to BSP suffer from the poor quality of the bound provided by the linear relaxation, even after strengthening. We devise an implicit enumeration scheme that attempts to overcome this difficulty. It is based on a formulation of BSP, which is equivalent to a stable set problem with one side constraint. This allows to exploit the upper bound, not only for pruning subproblems, but also for controlling the number and the quality of the subproblems generated. We show the effectiveness of the approach by an extensive computational experience on real‐sized randomly generated instances. © 2004 Wiley Periodicals, Inc. NETWORKS, Vol. 44(2), 151–159 2004
A neighborhood search algorithm for the combined through and fleet assignment model with time windows
Authors: Ahuja Ravindra K. , Liu Jian , Orlin James B. , Goodstein Jon , Mukherjee Amit
Published: July 2004

The fleet assignment model (FAM) for an airline assigns fleet types to a set of flight legs that satisfies a variety of constraints and minimizes the cost of the assignment. The through assignment model matches inbound flight legs into a city with the outbound flight legs at the same city that are flown by the same plane types and creates through connections (that is, flight connections with one stopover). The combined through and fleet assignment model (ctFAM) integrates both the models into a single model and obtains optimal fleet and through assignments by varying both sets of decision variables simultaneously. In a recent article, Ahuja et al. (2001) proposed a very large‐scale neighborhood (VLSN) search algorithm for the ctFAM. In this article, we generalize this approach to incorporate time windows. In the model considered in this article, each flight leg has a time window associated with its departure time. The objective is to determine fleet assignment, departure time of all flight legs, and through connections between flights to minimize the total cost of fleet assignment and through connections. We call this model ctFAM with time windows or ctFAM‐TW. Allowing flexibility in the flight departure time creates greater opportunities for fleet assignment and through connections, and can reduce costs substantially. We describe the details of a VLSN search algorithm for ctFAM‐TW and also present computational results of our algorithm on the data provided by a large U.S. airline. © 2004 Wiley Periodicals, Inc. NETWORKS, Vol. 44(2), 160–171 2004
Desirable features in mold filling simulations for Liquid Composite Molding processes
Authors: Šimáček Pavel , Advani Suresh G.
Published: July 2004

Numerical simulations of the mold filling process in various Liquid Composite Molding (LCM) techniques, in which the fiber reinforcements represent the porous media and the polymeric resin is the impregnating fluid, have been successfully utilized for over a decade now, but they continue to be under dynamic development. Some of the recent applications are the increased emphasis on design optimization, control of the impregnation process and the rapid introduction of new LCM techniques such as the Vacuum Assisted Resin Transfer Molding (VARTM). This paper describes the requirements that these new applications demand on the implementation of such numerical simulation for modeling mold filling in LCM processes, namely Resin Transfer molding (RTM) and VARTM. Liquid Injection Molding Simulation (LIMS) developed at the University of Delaware, which can simulate the flow in such processes, has been modified to encompass these features. It addresses practical issues concerning modeling the part geometry, such as the proper choice of one‐, two‐ and three‐dimensional elements and their effective combinations. It also describes the simulation of non‐trivial boundary conditions, placement of sensors and allowing for resin injection control using the functions built into the simulation program and the embedded scripting language. Several examples are presented to highlight the importance of its flexibility. The paper also addresses some VARTM specific issues, such as the modeling of distribution media, dimensional change during filling and fiber tow saturation. Polym. Compos. 25:355–367, 2004. © 2004 Society of Plastics Engineers.
Effect of reinforcing glass fibers on morphology and properties of thermoplastic modified epoxy‐aromatic diamine matrix
Authors: Bonnaud L. , Pascault J. P. , Sautereau H. , Zhao J. Q. , Jia D. M.
Published: July 2004

A usual way to improve the fracture toughness of thermosetting polymers consists of using an initially miscible thermoplastic that phase separates at a particular conversion, depending on composition and reaction temperature. This work deals with the effect of glass reinforcing fibers on the morphologies of polyetherimide and aminografted polyetherimide toughened epoxy‐diamine systems. The presence of fibers in these systems does not affect the phase separation process, but the final morphology changes in the case where polyetherimide (PEI) is used as an additive. Furthermore, the use of aminografted PEI does not change the previously observed morphology. In terms of mechanical properties, the use of fibers leads to a great improvement in the fracture energy, indicating that good adhesion between fiber and matrix is also achieved. Polym. Compos. 25:368–374, 2004. © 2004 Society of Plastics Engineers.
Non‐isothermal flow of a polymeric liquid through rounded rectangular ducts
Authors: Wu G. H.
Published: July 2004

The 3D non‐isothermal creeping flow of nylon‐6 in a bent rectangular duct is studied numerically. A differential‐type non‐isothermal White‐Metzner constitutive equation is used for this flow simulation. Computational results are obtained by the elastic‐viscous split‐stress (EVSS) finite element method, incorporating the streamline‐upwind Petrov‐Galerkin (SUPG) scheme. The generated thermal field is entirely due to viscous heating. Essential flow characteristics, including temperature distribution in the flow field, are predicted. The resulting average Nusselt numbers along the walls and dimensionless bulk temperatures along the channel are obtained. Subsequently, the effects of flow‐rate and geometry are investigated. Polym. Compos. 25:375–383, 2004. © 2004 Society of Plastics Engineers.
Experimental and numerical analysis of flow behavior in the FASTRAC liquid composite manufacturing process
Authors: Allende Melquiades , Mohan Ram V. , Walsh Shawn M.
Published: July 2004

The success of resin infusion during liquid composite processing depends on several factors; including the complete impregnation of the dry performs, the processing conditions, and the tooling used during processing. New process developments based on the Fast Remotely Actuated Channels (FASTRAC) process aid the infusion with the creation of preferential resin flow paths using a non‐contact tooling. Experiments to understand and study the infusion behavior with the presence of the FASTRAC non‐contacting tooling have been performed, and compared with vacuum‐assisted processes without such tooling. Experimental studies indicate that the infusion time with FASTRAC channel configurations is significantly less despite the additional volume regions to be infused during processing. The use of a non‐contacting interchangeable tool, the improved infusion behavior, and the significant reduction in the infusion time provide significant advantages for processing advanced composite systems, including the potential to use high viscosity resin systems, and process automation. The process simulation models of the experimental configurations based on the thin shell model configurations have been compared with experimental observations. Studies indicate that the process simulation models and approaches employed clearly emulate the infusion behavior seen when the channels are present, validating the modeling strategies employed. Similar simulation approaches will thus be effective to study and understand various FASTRAC tooling configurations while processing complex composite structures. Polym. Compos. 25:384–396, 2004. © 2004 Society of Plastics Engineers.
Shielding effectiveness of carbon‐filled nylon 6,6
Authors: Heiser Jessica A. , King Julia A. , Konell Jeremiah P. , Sutter Lawrence L.
Published: July 2004

Electrically conductive resins can be made by adding electrically conductive fillers to typically insulating polymers. Resins with an electrical resistivity of approximately 100 ohm‐cm or less can be used for electromagnetic and radio frequency interference shielding applications. This research focused on performing compounding runs followed by injection molding and shielding effectiveness testing of carbon filled nylon 6,6 based resins. The three carbon fillers investigated included an electrically conductive carbon black, synthetic graphite particles, and a surface‐treated polyacrylonitrile (PAN)‐based carbon fiber. Conductive resins were produced and tested that contained varying amounts of these single carbon fillers. In addition, combinations of fillers were investigated by conducting a full 23 factorial design and a complete replicate. The objective of this paper was to determine the effects and interactions of each filler on the shielding effectiveness properties of the conductive resins. Carbon fiber caused the largest increase in shielding effectiveness. Also, all the single fillers and combinations of fillers were statistically significant at the 95% confidence level, except the composite containing carbon black and synthetic graphite particles tested at 800 MHz. Polym. Compos. 25:407–416, 2004. © 2004 Society of Plastics Engineers.
Void transport in resin transfer molding
Authors: Kang Kai , Koelling Kurt
Published: July 2004

The transport of single drops through a hexagonal cylinder array is used to study the void movement and deformation in a resin transfer molding process. A transparent flow cell is used to visualize the transport of voids through a porous media model. Experiments are conducted with nearly inviscid water drops and viscous glycerol drops with drop sizes ranging from 0.4 to 80 μl, and with both a Newtonian fluid and Boger fluid with average resin velocities ranging from 0.011 to 0.140 cm/s. Two critical capillary numbers, which determine the breakup (Cab) and mobilization (Ca*) of drops, are measured to better understand the flow dynamics of voids. As demonstrated by the experiments, there is a critical drop size, below or above which a quite different flow behavior is observed. Such a transition is analyzed with consideration of the geometry characters in the flow field. Results expand the former studies in this area to a significantly larger range of drop sizes and capillary numbers. Particle Tracking Velocimetry is also used to quantify the local velocity, shear stress, extensional stress and energy dissipation in the flow field. Polym. Compos. 25:417–432, 2004. © 2004 Society of Plastics Engineers.
Parallel isoelectric focusing chip
Authors: Zilberstein Gleb , Korol Leonid , Bukshpan Shmuel , Baskin Emanuil
Published: July 2004

Fast isoelectric focusing (IEF) is becoming a key method in modern protein analysis. We report here the theory and experimental results of new parallel isoelectric devices (PID) for fast IEF. The main separation tool of any PID is a dielectric membrane with conducting channels filled by immobiline gels of varying pH. The pH value of the surrounding aqueous solution is not equal to the pH of any of the channels. The membrane is held perpendicular to the applied electric field. Proteins are collected (trapped) in the channels whose pH values are equal to the pI of the proteins. The fast particle transport between different channels takes place due to convection in the aqueous solution. We developed a mathematical model for PID. Experiment duration is shown to be proportional to the number of different bands N (the peak capacity in standard IEF) in contrast with N2 for usual IEF devices. This model was validated with experimental results. Parallel IEF accelerates the fractionation of proteins by their pI values (down to several minutes) allowing a more desirable collection efficiency to be achieved. The main theoretical limitation of PID resolution is the sensitivity of proteins to pH change due to the Coulomb blockade effect. The existence of a minimal pH change δpHmin for each type of protein is shown: δpHmin ∼ r−1 for globular molecules with radius r.
Homology‐based functional proteomics by mass spectrometry: Application to the Xenopus microtubule‐associated proteome
Authors: Liska Adam J. , Popov Andrei V. , Sunyaev Shamil , Coughlin Peg , Habermann Bianca , Shevchenko Anna , Bork Peer , Karsenti Eric , Shevchenko Andrej
Published: July 2004

The application of functional proteomics to important model organisms with unsequenced genomes is restricted because of the limited ability to identify proteins by conventional mass spectrometry (MS) methods. Here we applied MS and sequence‐similarity database searching strategies to characterize the Xenopus laevis microtubule‐associated proteome. We identified over 40 unique, and many novel, microtubule‐bound proteins, as well as two macromolecular protein complexes involved in protein translation. This finding was corroborated by electron microscopy showing the presence of ribosomes on spindles assembled from frog egg extracts. Taken together, these results suggest that protein translation occurs on the spindle during meiosis in the Xenopus oocyte. These findings were made possible due to the application of sequence‐similarity methods, which extended mass spectrometric protein identification capabilities by 2‐fold compared to conventional methods.
The principle of nonperfect synchronization: how does it apply to aromatic systems?
Authors: Bernasconi C. F.
Published: July 2004

According to the Principle of Nonperfect Synchronization (PNS), a product‐stabilizing factor, the development of which at the transition state lags behind bond changes, increases the intrinsic barrier of a reaction, but lowers it if it develops ahead of bond changes. Because of the generality of this principle, details of transition state structures can be deduced from comparisons of intrinsic barriers within classes of reactions. A major conclusion that has emerged from such comparisons is that reactions that lead to charge delocalization/resonance stabilized products have transition states in which the development of charge delocalization/resonance stabilization lags behind bond changes and, hence, have relatively high intrinsic barriers. This paper deals with reactions that lead to aromatic molecules or ions. The question we are asking is whether or not aromaticity follows the pattern of common resonance effects and lags behind bond changes at the transition state. Evidence based on experimentally determined intrinsic barriers of proton transfers from rhenium carbene complexes in solution, as well as that based on ab initio calculations of proton transfers in the gas phase, suggests that aromaticity development at the transition state may actually be ahead of bond changes. Copyright © 2004 John Wiley & Sons, Ltd.
Role of cyclic dithiocarbonate as a promoter in the reaction of epoxide and imine in the presence of water
Authors: Suzuki Kentarou , Horii Hisakazu , Sugita Yuko , Sanda Fumio , Endo Takeshi
Published: July 2004

It was demonstrated that the reaction of epoxide and imine as a latent initiator under highly humid conditions was accelerated by addition of 5‐phenoxymethyl‐1,3‐oxathiolane‐2‐thione (1). When 1 was added to a mixture of glycidyl phenyl ether and an imine, the reaction of the epoxide with an amine released from the imine became faster than was the case without 1, that is, 1 worked as a promoter of the reaction. The curing rate and initial adhesive strength of epoxy resin increased compared with that without 1. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4276–4283, 2004
Konjac glucomannan‐graft‐acrylic acid hydrogels containing azo crosslinker for colon‐specific delivery
Authors: Liu Zhi‐Lan , Hu Han , Zhuo Ren‐Xi
Published: July 2004

In this article, the synthesis and characterization of novel hydrogel systems designed for colon‐targeting drug delivery are reported. The gels were composed of konjac glucomannan, copolymerized with acrylic acid, and crosslinked by the aromatic azo agent bis(methacryloylamino)‐azobenzene. The influence of various parameters on the dynamic and equilibrium swelling ratios (SRs) of the hydrogels was investigated. It is shown that the SR was inversely proportional to the grafting degree of acrylic acid and the content of bis(methacryloylamino)‐azobenzene. The dependence of SR on the pH indicates that obtained hydrogels are potential for drug delivery to colon. It was possible to modulate the degree of swelling and the pH sensitivity of the gels by changing crosslinking density of the polymer. The main chain of hydrogels can be degraded by β‐glycosidase which is abundant in colon. They can be in vitro degraded for 73% in a month by Cereflo® and 86% in 20 days by Mannaway25L. We have also prepared the hydrogels that loaded with bovine serum albumin about 1.5%, 3%, 9%, and 20% by weight. In vitro release of model drug bovine serum albumin was studied in the presence of Mannaway25L or Fungamyl®800L in pH 7.4 phosphate buffer at 37 °C. The drug release can be controlled by the biodegradation of the hydrogels. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4370–4378, 2004
Gel‐like aspect of a miscible polymer mixture studied by small‐angle neutron scattering
Authors: Koizumi Satoshi
Published: July 2004

By employing small‐angle neutron scattering (SANS), we have investigated a miscible mixture of polystyrene (PS) and poly(vinyl methyl ether) (PVME) to answer the question of what a gel state is. The large difference in the glass‐transition temperatures (Tg's) of PS and PVME uniquely enhances dynamic asymmetry by a temperature change. In an intermediate temperature range between the two Tg's, SANS reveals two interesting findings: (1) the anomalous suppression of small‐angle scattering in a quiescent state and (2) an abnormal butterfly scattering pattern due to shear‐induced phase separation. In this temperature region, we have further confirmed experimentally that the mixture behaves in a gel‐like limit at which concentration fluctuations relax more quickly than rheological relaxation. With the gel‐like limit and enhanced dynamic asymmetry, which is required for the gel state, our two SANS findings can be interpreted within the theoretical framework of dynamical coupling between stress and diffusion. For comparison, we have studied a swollen real chemical gel of poly(N‐isopropyl acrylamide), in which covalent bonds crosslink chains heterogeneously. A combined method of SANS and neutron spin echo has been used to quantitatively determine the static inhomogeneity, which gives rise to a structure factor of a squared Lorentzian shape. The static inhomogeneity is closely related to the nonergodic feature of excess scattering when the gel is subjected to swelling or nondecaying abnormal butterfly scattering under deformation. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3148–3164, 2004
Time‐resolved small‐angle neutron scattering study of polyethylene crystallization from solution
Authors: Wang Howard
Published: July 2004

With time‐resolved small‐angle neutron scattering (TR‐SANS), the crystallization kinetics of polyethylene from deuterated o‐xylene solutions upon a temperature jump have been investigated. On the basis of a morphological model of coexisting lamellar stacks and coil chains in solution, experimental data have been quantitatively analyzed to provide structural information, such as the lamellar long period, the lamellar crystal thickness, the thickness of the amorphous layers between lamellae, the degree of crystallinity, and the crystal growth rate at various degrees of undercooling. The viability of TR‐SANS for studying polymer crystallization is demonstrated through the consistency of these measurements and well‐established knowledge of polyethylene crystallization from xylene solutions. One unique feature of this experimentation is that both the growth of lamellar crystals and the condensation of coil chains from solution are monitored simultaneously. The ratio of the crystal growth to the chain consumption rate decreases rapidly with a decreasing degree of undercooling. The Avrami analysis suggests that the growth mechanism approaches two‐dimensional behavior at higher temperatures, and this is consistent with the observation of an increasing ratio of the sharp‐surface area to the bulk crystal growth rate with temperature. The limitations, possible remedies, and potentials of TR‐SANS for studying polymer crystallization are discussed. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3133–3147, 2004
Quality of life and psychological adaptation in siblings of paediatric cancer patients, 2 years after diagnosis
Authors: Houtzager B.A. , Grootenhuis M.A. , Caron H.N. , Last B.F.
Published: July 2004

Several studies have been conducted on sibling psychosocial adaptation to cancer in a brother or sister, but little is known on how the long‐term adaptation of siblings to the illness develops. The concept quality of life has primarily been applied in research on the effects of chronic illness on the affected patient, but has not yet been studied in siblings. Aims: To investigate the prevalence of self‐reported psychosocial problems in siblings of pediatric cancer patients, 2 years after the onset of the illness. Measurements: Two Dutch quality of life questionnaires, the TACQOL and the DUCATQOL are used, as well as generic non‐health‐related measures of emotional and behaviour problems (CBCL‐YSR) and anxiety (STAI‐C). Participants: Participants were 103 siblings aged 7–18 years old. Fifty seven Siblings participated in a prospective and 46 in a retrospective study group. Results: Siblings aged 7–11 report lower overall quality of life than children in the norm group. No differences in mean scores were found on any of the other domains that were investigated. When the prevalence of problems was investigated, however, relatively more siblings compared to normative data had scores in the impaired group based on the 20th percentile norm. A relatively high number of siblings aged 7–11 reported impaired emotional (42%), social (34%) and total quality of life (47%) (DUCATQOL) and physical problems (26%) (TACQOL). Relatively many adolescent siblings (26%) reported significant internalising problems on the CBCL‐YSR. Conclusions: Although acute emotional distress reactions seem to have normalised in most siblings as has been suggested in the literature, emotional distress of having a brother or sister with cancer may continue beyond diagnosis for a subgroup of children. Young siblings seem to be affected in their quality of life, whereas a subgroup of adolescent siblings experience clinically relevant internalising problems. The results support the use of quality of life measures for siblings. Predictors of long‐term adaptation in siblings need to be investigated. Copyright © 2003 John Wiley & Sons, Ltd.
Parent‐reported environmental tobacco smoke exposure among preadolescents and adolescents treated for cancer
Authors: Tyc Vida L. , Klosky James , Throckmorton‐Belzer Leslee , Lensing Shelly , Rai Shesh N.
Published: July 2004

Exposure to environmental tobacco smoke (ETS) poses serious health risks for children with cancer. Parental smoke is a primary source of exposure for these children. Parent smoking behaviors and parent‐reported ETS exposure among children treated for cancer were examined in this study. In addition, reports of ETS exposure among children with cancer who currently smoked or who had smoked in the past were compared to those of children with cancer who never smoked. Written questionnaires about smoking behaviors and ETS exposure were administered to 47 smoking parents of youngsters diagnosed with cancer, 10–18 years of age (57.4% male, 78.7% Caucasian). Child reports of smoking status were also obtained. Results indicated that children with cancer are exposed to ETS from a number of sources and settings, as reported by their parents. Current or previous child smokers had greater ETS exposure than non‐smoking children. Older children and Caucasian children also had greater ETS exposure. Level of ETS exposure did not differ based on the child's treatment status. Interventions that teach parents to protect their youngster from ETS exposure have potential for reducing adverse health outcomes in this vulnerable population. Copyright © 2003 John Wiley & Sons, Ltd.
The psychological impact of a cancer diagnosis on families: The influence of family functioning and patients' illness characteristics on depression and anxiety
Authors: Edwards Ben , Clarke Valerie
Published: July 2004

A diagnosis of cancer is a very stressful event for the patients and their families. Patients, partners and other family members can suffer from clinical levels of depression and severe levels of anxiety and stress reactions. The similarity in levels of distress between patients and partners and patients and offspring suggests that there are common factors that impact on families' distress levels. The current study examined levels of depression and anxiety in newly diagnosed adult patients (n=48) and their adult relatives (n=99). Family functioning and patients' illness characteristics were identified as factors that might impact on families' depression and anxiety. Results from multilevel models indicated that family functioning was important. Families that were able to act openly, express feelings directly, and solve problems effectively had lower levels of depression. Direct communication of information within the family was associated with lower levels of anxiety. Aside from differences anxiety due to cancer type, patients' illness characteristics appear to be risk factors in patients' but not relatives' depression and anxiety. The results from the current study suggest that researchers and clinicians need to be family‐focused as cancer affects the whole family, not just the patient. Copyright © 2003 John Wiley & Sons, Ltd.
Ranking the risk of pesticide dietary intake
Authors: Low Felicia , Lin Hui‐Ming , Gerrard Juliet A , Cressey Peter J , Shaw Ian C
Published: July 2004

Pesticide residues in various foods were assessed for the relative risk to the consumer. The analysis took into account criteria such as a pesticide's toxicity, usage, frequency of occurrence in foods, frequency of Maximum Residue Level (MRL) exceedances, and the overall risks of specific pesticide/food combinations. Examination of the top ten ranked pesticides for each criterion showed that there are no trends of commonality. Thus, no single pesticide is of particular concern from a consumer's point of view. This suggests that the consumer's risk perception is likely to be higher than justified. Copyright © 2004 Society of Chemical Industry
Nonlinear Seebeck and Peltier effects in quantum point contacts
Authors: Çipiloğlu M. A. , Turgut S. , Tomak M.
Published: July 2004

The charge and entropy currents across a quantum point contact are expanded as a series in powers of the applied bias voltage and the temperature difference. After that, the expansions of the Seebeck voltage in temperature difference and the Peltier heat in current are obtained. With a suitable choice of the average temperature and chemical potential, the lowest order nonlinear term in both cases appear to be of third order. The behavior of the third‐order coefficients in both cases are then investigated for different contact parameters. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Stereospeciﬁc effects of catechin isomers on insulin induced lipogenesis in 3T3‐L1 cells
Authors: Mochizuki Miyako , Hasegawa Noboru
Published: July 2004

We studied the inﬂuence of (+)‐ and (−)‐catechin contained in green tea on insulin induced lipogenesis in 3T3‐L1 cells. In 14 days of culture with insulin, the intracellular triglyceride concentration and the activities of glycerophosphate dehydrogenase, a marker of adipose conversion, increased. The addition of 0.02 mg/ml (+)‐isomer stimulated the accumulation of triglyceride induced by insulin, but the addition of the same concentration of (−)‐isomer inhibited lipogenesis. The activities of glycerophosphate dehydrogenase were changed by (+)‐ and (−)‐catechin in the same direction as the corresponding changes in triglyceride accumulation. These data suggest a biological signiﬁcance of catechins, with opposite effects on lipid metabolism depending on the isomer. Copyright © 2004 John Wiley & Sons, Ltd.
Inhibitory effects of leaf extracts of Stachytarpheta jamaicensis (Verbenaceae) on the respiratory burst of rat macrophages
Authors: Álvarez Ezequiel , Leiro José Manuel , Rodríguez Melita , Orallo Francisco
Published: July 2004

The anti‐oxidant effects of ethyl acetate (EAcE) and n‐hexane extracts (nHE) of dried leaves of Stachytarpheta jamaicensis Vahl. (Verbenaceae) on the reactive oxygen species (ROS) generating during the respiratory burst of rat peritoneal macrophages were investigated. Only EAcE, at concentrations between 0.4 and 40 µg/ml, inhibited the extracellular release of oxygen radicals by resident peritoneal macrophages stimulated with phorbol‐12‐myristate 13‐acetate (PMA). At concentrations above 40 µg/ml, EAcE inhibited the production of nitric oxide (NO) in macrophages stimulated in vivo with sodium thioglycollate then in vitro with lipopolysaccharide (LPS) and gamma‐interferon (IFN‐γ). nHE extracts at concentrations between 0.4 and 40 µg/ml did not scavenge O−2 generated enzymatically by hypoxanthine/xanthine oxidase (HX/XO) system, but EAcE at the same concentrations showed potent O−2‐scavenging activity. At 40 µg/ml, EAcE also inhibited XO activity. These results suggest that the EAcE extract of S. jamaicensis may be a potential pharmaceutical value in treatment of immunopathological diseases related to oxidative stress. Copyright © 2004 John Wiley & Sons, Ltd.
Structural criteria for depigmenting mechanism of arbutin
Authors: Hori Ikuyo , Nihei Ken‐ichi , Kubo Isao
Published: July 2004

Arbutin, hydroquinone‐O‐β‐d‐glucopyranoside (1) was found to inhibit the oxidation of l‐tyrosine (monophenolase activity) catalyzed by mushroom tyrosinase. However, arbutin itself was oxidized as a monophenol substrate at an extremely slow rate, and this oxidation was accelerated as soon as catalytic amounts (0.01 mm) of l‐3,4‐dihydroxyphenylalanine (l‐DOPA) became available as a cofactor. The result observed was supported by monitoring oxygen consumption. The depigmenting mechanism of arbutin previously reported is supportable if a cofactor is not available in the melanocytes. The combination with l‐ascorbic acid is a useful application, particularly when oxygen is limited. Copyright © 2004 John Wiley & Sons, Ltd.
Attenuating effect of a traditional korean formulation, Paeng‐Jo‐Yeon‐Nyeon‐Baek‐Ja‐In‐Hwan (PJBH), on hydrogen peroxide‐induced injury in PC12 cells
Authors: Koo Byung‐Soo , Kim Yeon‐Kye , Park Kyung‐Su , Chung Kang‐Hyun , Kim Cheorl‐Ho
Published: July 2004

The Paeng‐Jo‐Yeon‐Nyeon‐Baek‐Ja‐In‐Hwan (PJBH) prescription is a dried decoctum consisting of a mixture of 18 medicinal herbs that include Semen Biotae, Fructus Torilis seu cnidii, Fructus Rubi, Herba Dendrobii, Radix Morindae ofﬁcinalis, Cortex Eucommiae, Radix Aspragi, Radix Polygalae, Radix Dipsaci, Ramulus Cinnamomi, Rhizoma Acori graminei, Rhizoma Alismatis, Rhizoma Dioscoreae, Radix Ginseng, Radix Rehmanniae preparata, Fructus corni, Fructus Schisandrae and Herba Cistanches. The effect of PJBH extracts on H2O2‐induced toxicity in the rat pheochromocytoma line PC12 was examined by measurements of cell lesion, level of lipid peroxidation and antioxidant enzyme activities, since free radicals are involved in neurodegeneration in Alzheimer's disease (AD). After a 30 min exposure of the cells to H2O2 (150 µM), a marked decrease in cell survival, activities of glutathione peroxidase and catalase as well as an increased production of malondialdehyde (MDA) were found. Pretreatment of the cells with PJBH (0.5–10 µg/ml) prior to H2O2 exposure signiﬁcantly elevated cell survival, antioxidant enzyme activities and resulted in a decrease in the level of MDA. The effects of the PJBH on hydrogen peroxide‐induced injury in PC12 cells were also examined. PJBH had a remarkable elevating effect on catalase and GSH‐Px activities as well as cell survival, suggesting that cytoprotective effects of the PJBH are involved in stimulation against intermediate concentrations of H2O2‐induced PC12 cell injury. The above‐mentioned neuroprotective effects were also compared with the effect of tacrine. The results suggest that PJBH has potential for use as a novel neuronal therapeutic agent. Copyright © 2004 John Wiley & Sons, Ltd.
Methods to study the phytochemistry and bioactivity of essential oils
Authors: Lahlou Mouhssen
Published: July 2004

Many essential oils are extracted, analysed and their main components are identiﬁed, characterised and then published without any biological testing whatsoever. Their useful biological activities can remain unknown for years. Yet, the search for these activities often increases our knowledge of the potential use of oils in therapeutics. Therefore, there is a real need for a simple, reliable and reproducible methods to study the bioactivity of essential oils and their constituents which can detect a broad spectrum of action or speciﬁc pharmacological activities in aromatic plants. These methods can then be employed by natural product chemists, pharmacologists and biologists to conduct their scientiﬁc research and to valorise natural products. Standardisation of some of these methods is therefore desirable to permit more comprehensive evaluation of plant oils, and greater comparability of the results obtained by different investigators. Copyright © 2004 John Wiley & Sons, Ltd.
Antifungal activity of actinomycetes from cuban soils
Authors: Iznaga Y. , Lemus M. , González L. , Garmendía L. , Nadal L. , Vallín C.
Published: July 2004

This study reports on the capacity of actinomycete strains isolated from Cuban soils to produce antifungal agents. The antimicrobial activities were determined by susceptibility disk assay methods. We isolated 563 different actinomycetes and 286 produced compounds with antifungal activity. Our screening method indicated the presence of many possible polyene macrolide antibiotics and the important antifungal activity in the soils rich in minerals. Copyright © 2004 John Wiley & Sons, Ltd.
Antibacterial activity of the Chinese traditional medicine, Zi Hua Di Ding
Authors: Xie Chen , Kokubun Tetsuo , Houghton Peter J. , Simmonds Monique S. J.
Published: July 2004

The antibacterial activity of extracts from species of plants used in the Chinese medicine, Zi Hua Di Ding (Viola yedoensis, V. prionantha, Corydalis bungeana and Gueldenstaedtia verna), was tested against Bacillus subtilis and Pseudomonas syringae using a bioautographic assay. The petroleum ether and ethyl acetate extracts of all four species of plants showed activity against both species of bacteria, whereas the methanol and aqueous methanol extracts were inactive. Three fractions from the petroleum ether extracts of V. yedoensis, V. prionantha and C. bungeana showed activity against B. subtilis at 6.25 µg/mL. Preliminary analysis of these active fractions indicates that they contain long chain carboxylic acids. Copyright © 2004 John Wiley & Sons, Ltd.
Measurement System Analysis for Bounded Ordinal Data
Authors: de Mast Jeroen , van Wieringen Wessel
Published: July 2004

The precision of a measurement system is the consistency across multiple measurements of the same object. This paper studies the evaluation of the precision of measurement systems that measure on a bounded ordinal scale. A bounded ordinal scale consists of a finite number of categories that have a specific order. Based on an inventory of methods for the evaluation of precision for other types of measurement scales, the article proposes two approaches. The first approach is based on a latent variable model and is a variant of the intraclass correlation method. The second approach is a non‐parametric approach, the results of which are, however, rather difficult to interpret. The approaches are illustrated with an artificial data set and an industrial data set. Copyright © 2004 John Wiley & Sons, Ltd.
Optimization of a Car Brake Prototype as a Consequence of Successful DOE Training
Authors: Marco Lluís , Tort‐Martorell Xavier , Cuadrado Juan A. , Pozueta Lourdes
Published: July 2004

In this article we discuss the importance of running a successful experiment while teaching design of experiments (DOE) to working engineers. A key aspect is to build engineer's confidence in DOE methodology and in their capabilities of using it, and this means keeping the content simple and developing a learning‐by‐doing experience. We cover several aspects of the course content and preparation, but the emphasis is in the preparation, follow up, roles of teachers and attendants, and the planning and steps followed in preparing and conducting the real experiment. A crucial aspect is making sure that the attendants recognize that they have gained valuable knowledge. A measure of the success of the approach suggested is that after the course and the real experiment associated with it were finished, Bosch's engineers have run several other experiments completely on their own. Even though a professional statistician may have done a better job, the use of the techniques were correct and the learning from the experiments was highly valuable. Copyright © 2004 John Wiley & Sons, Ltd.
Designing Phase I ―X Charts with Small Sample Sizes
Authors: Champ Charles W. , Jones L. Allison
Published: July 2004

Methods are examined for obtaining probability limits for Phase I Shewhart ―X charts when the process mean and standard deviation are estimated. The design methods assume m independent random samples of size n will be taken periodically from a normally distributed process. It is shown that the joint distribution of the standardized subgroup means follows either an approximate or exact multivariate t distribution, depending on the standard deviation estimator used. The multivariate t distribution is used to define the probability limits for the Phase I ―X chart. Extensive simulation compares the performance of the proposed limits with other design procedures. Tables of design constants are given for $m<20$, and simple procedures for obtaining design constants are given for $m\geq 20$. Copyright © 2004 John Wiley & Sons, Ltd.