bluuebunny/crossref_metadata_2025 huggingface dataset:
Force Characteristics of Tire Tread Delamination
Authors: Daws J. W.
Published: June 2006

Belt-leaving-belt tread separations in radial tires have been pointed out as a cause of vehicle accidents. This paper presents the results of measurements on the level of forces generated during a tread delamination. This study showed that tires that had been cut to generate a belt-leaving-belt separation always generated a leading edge flap and that the interaction of this flap with the vehicle body is responsible for the tractive force generation. The research also showed that the total impulse generated by a belt-leaving-belt separation represents a small fraction of the total vehicle momentum at highway speed.
Measurement of the Slip of Tread Blocks in the Contact Patch
Authors: Koehne S. H. , Rieger A.
Published: June 2006

For the tread pattern design, irregular wear of a tire is an essential development criterion. From a physical point of view, irregular wear results from frictional energy exerted onto the individual tread blocks. The local tangential stresses and movements are needed for the calculation of the local frictional energy.

The measurement of slip is carried out optically using a line scan camera. The line scan camera enables measurements at real speeds (40 kmph) due to the camera's very high scan frequency. The picture acquirement is done through a glass window within a rotating drum of a test stand. With repeating roll over, the complete tire can be measured.

Finally, stresses and slip are combined to frictional energy to be visualized in colored distribution onto the block surface as indication for local wear behavior. In order to validate the measurements and calculations, four different tread pattern with different stiffness due to tread design and compounding are investigated. For the validation, the block stiffness, frictional energy and irregular wear results are compared with each other.
Tire Acoustic Optimization Using Point Damping Method
Authors: Wang X. , Gauterin F. , Saemann E-U.
Published: June 2006

In order to reduce vehicle tire/road induced interior noise and improve ride comfort, tires with optimized damping should be adopted for a vehicle.

The tire acoustic optimization will be evaluated by a point damping method in this paper. The point damping method allows for a direct calculation and measurement of tire damping. It relates the tire damping to tire design parameters such as stiffness, mass density, material properties and dimensions. The point damping method will be a useful tool for tire acoustic optimization.

The point damping method will be illustrated in this paper. Tires will be simplified as built up structures such as beams, plates, shells, and rings for tire damping calculation. Single and multi-parameter optimizations will be discussed. A laboratory measurement method for tire point damping will be illustrated.
Tire Lateral Force Modeling and the Bushing Analogy Tire Model
Authors: Kao B. G. , Warholic T.
Published: June 2006

The Bushing Analogy Tire (BAT) model has been studied for tire dynamics modeling in vertical and lateral directions. It was shown that the vibration characteristics included in the BAT model in the vertical and lateral directions cover the tire modes in those directions up to about 100 Hz. This capability of the BAT model is suitable for vehicle ride simulations. However, in vehicle handling situations such as accident avoidance, the tire is subjected to sudden steering motions that are not included in the vertical and lateral dynamics. The steering generates tire slip angle and, hence, the lateral forces for vehicle direction change. The tire steering motion also generates the aligning torque, which modifies the slip angle of the tire with respect to the wheel input steering angle. The tire steering compliance is therefore important for the dynamic responses during the vehicle handling maneuvers. In this paper, tire compliance in the steering direction is studied by treating the steering motion as an independent motion of the 3-dimentional tires.

In this paper, the steering stiffness (or compliance) of a tire is first derived from the analysis results of a tire Finite Element (FE) model. Comparing the steering direction vibration modes using the BAT model with the FE model extracted modes further validates the steering stiffness. The coupling of tire steering stiffness with the vertical forces is also studied. Then, the effects of the tire steering direction stiffness are used to study a data set of flat-track generated tire lateral force and moment. The procedure of generating required coefficients of a handling tire model coupled with tire dynamic features of the BAT model were also investigated.
Towards self‐organisational and multiple‐performance capacity in architecture
Authors: Hensel Michael , Menges Achim , Weinstock Michael
Published: June 2006

Techniques and Technologies in Morphogenetic Design expands and develops the themes of the previous, highly successful Emergence: Morphogenetic Design Strategies issue of 4 (Vol 74, No 3, 2004), which was also guest‐edited by Michael Hensel, Achim Menges and Michael Weinstock of the Emergence and Design Group. While the first volume elucidated the concepts of emergence and self‐organisation in relation to the discipline of architecture, this issue augments its theoretical and methodological foundation within a biological paradigm for architectural design, while also discussing promising, related, instrumental techniques for design, manufacturing and construction. Michael Hensel introduces the issue and explains how it addresses a much broader range of scales, from the molecular to that of macro‐structure and, beyond, to ecological relations. Copyright © 2006 John Wiley & Sons, Ltd.
Effect of Hole Mobility Through Emissive Layer on Temporal Stability of Blue Organic Light‐Emitting Diodes
Authors: Culligan S. W. , Chen A. C.‐A. , Wallace J. U. , Klubek K. P. , Tang C. W. , Chen S. H.
Published: June 2006

Light‐emitting conjugated oligomers comprising anthracene, naphthalene, and fluorene units have been synthesized to investigate three configurations of blue organic light‐emitting diodes (OLEDs) that are designed to identify the origins of device instability. The transient OLED technique is employed to measure hole mobilities, which are found to be 3.1 × 10–4, 8.9 × 10–5, and 3.6 × 10–5 cm2 V–1 s–1 for three different blue‐light‐emitting model compounds with varying fluorene content. A higher hole mobility through the emissive layer results in a wider recombination zone, which, in turn, is responsible for a longer device lifetime and a lower drive voltage at the expense of luminance yield.
Systematic review of enhanced recovery programmes in colonic surgery
Authors:   Fast Track Multimodal Management Versus Standard Care (LAFA) study group,   Enhanced Recovery After Surgery (ERAS) group, Wind J , Polle S W , Fung Kon Jin P H P , Dejong C H C , von Meyenfeldt M F , Ubbink D T , Gouma D J , Bemelman W A
Published: June 2006

Background

Fast track (FT) programmes optimize perioperative care in an attempt to accelerate recovery, reduce morbidity and shorten hospital stay. The aim of this review was to assess FT programmes for elective segmental colonic resections.

Methods

A systematic review was performed of all randomized controlled trials and controlled clinical trials on FT colonic surgery. The main endpoints were number of applied FT elements, hospital stay, readmission rate, morbidity and mortality. Quality assessment and data extraction were performed independently by three observers.

Results

Six papers were eligible for analysis (three randomized controlled and three controlled clinical trials), including 512 patients. FT programmes contained a mean of nine (range four to 12) of the 17 FT elements as defined in the literature. Primary hospital stay (weighted mean difference − 1·56 days, 95 per cent confidence interval (c.i.) − 2·61 to − 0·50 days) and morbidity (relative risk 0·54, 95 per cent c.i. 0·42 to 0·69) were significantly lower for FT programmes. Readmission rates were not significantly different (relative risk 1·17, 95 per cent c.i. 0·73 to 1·86). No increase in mortality was found.

Conclusions

FT appears to be safe and shortens hospital stay after elective colorectal surgery. However, as the evidence is limited, a multicentre randomized trial seems justified.
Randomized clinical trial of the effect of quilting latissimus dorsi flap donor site on seroma formation
Authors: Daltrey I , Thomson H , Hussien M , Krishna K , Rayter Z , Winters Z E
Published: June 2006

Background

Latissimus dorsi (LD) flap breast reconstruction is associated with a high incidence of donor site seromas, despite the use of surgical drains. The aim of this study was to evaluate the use of donor site quilting sutures, as well as drains, on the incidence, volume and frequency of seroma aspiration.

Methods

The trial randomized 108 women undergoing LD breast reconstruction to quilting procedures (54) or control group (52) for intention-to-treat analysis; two were excluded. Outcome measures were the incidence and volume of postoperative seroma. Secondary outcome measures included postoperative back pain, analgesic consumption, shoulder movement and duration of hospital stay.

Results

Quilting significantly reduced the overall incidence of seroma from 46 of 48 (96 per cent) to 43 of 52 (83 per cent) (P = 0·036), including the 38 women who had extended LD flap (with or without implants). There were further significant reductions in seroma volume (P = 0·004), frequency of aspiration (P = 0·001) and overall seroma volumes, including surgical drainage and symptomatic seromas (P = 0·013). Subset analyses for LD–implant (60 women) and extended LD (with or without implant) showed similar significance. Quilting did not affect back pain or compromise shoulder mobility.

Conclusion

Quilting significantly reduced overall seroma volumes after LD breast reconstruction including extended LD, and is recommended in combination with surgical drains.
DBSC‐based animation enhanced with feature and motion
Authors: Chen Quan , Tian Feng , Seah HockSoon , Wu Zhongke , Qiu Jie , Konstantin Melikhov
Published: June 2006

Disk B‐spline curve (DBSC) is previously proposed for drawing and animation. To generate inbetweens, linear interpolation is applied between points evenly taken in parametric domain of two DBSCs without incorporating characteristics of shape or motion, which results in distortion and unrealistic motion in animation. In this paper, more information in keyframes is extracted and utilized in inbetween generation. Points with high curvature are computed and corresponded between strokes in interpolation, which preserves features of strokes in animation. In addition, global motion of a character or its various components is estimated and interpolated as well, which retains the shapes during the motion. By applying the information to interpolation, the distortion is eliminated and smoother sequence of animation is achieved. Copyright © 2006 John Wiley & Sons, Ltd.
Autonomous boids
Authors: Hartman Christopher , Benes̆ Bedr̆ich
Published: June 2006

The classical work of bird‐like objects of Reynolds simulates polarized motion of groups of oriented particles, bird‐like objects, or simply boids. To do this, three steering vectors are introduced. Cohesion is the tendency of boids to stay in the center of the flock, alignment smoothes their velocities to similar values, and separation helps them to avoid mutual collisions. If no impetus is introduced the boids wander somewhat randomly so an external leading force is necessary for the correct flock behavior. As can be observed during the bird flocking in the fall, birds sometimes move in a way that is not captured by the above described framework. Some of the birds, typically the ones on the edge of the flock, suddenly shoot‐off. The flock then pursues this leader. In the original work by Reynolds the cohesion and separation are two complementary steers. We introduce a complementary force to the alignment that we call the change of leadership. This steer defines the chance of the boid to become a leader and try to escape. The leadership is derived from the boid position and the flock eccentricity. If a boid is on the front edge of the flock it has a higher chance to escape. Escaping from the flock is simulated as a sequence of velocity increases that are added to the current velocity of the boid. The entire system is easy to implement, is efficient, and runs simulations of hundreds of boids on a standard computer at 30 frames per second. Our system is aimed to real‐time simulations and has the potential to be used in games, crowd simulations, etc. Copyright © 2006 John Wiley & Sons, Ltd.
Emotional face expression profiles supported by virtual human ontology
Authors: García‐Rojas A. , Vexo F. , Thalmann D. , Raouzaiou A. , Karpouzis K. , Kollias S. , Moccozet L. , Magnenat‐Thalmann N.
Published: June 2006

Expressive facial animation synthesis of human like characters has had many approaches with good results. MPEG‐4 standard has functioned as the basis of many of those approaches. In this paper we would like to lay out the knowledge of some of those approaches inside an ontology in order to support the modeling of emotional facial animation in virtual humans (VH). Inside this ontology we will present MPEG‐4 facial animation concepts and its relationship with emotion through expression profiles that utilize psychological models of emotions. The ontology allows storing, indexing and retrieving prerecorded synthetic facial animations that can express a given emotion. Also this ontology can be used a refined knowledge base in regards to the emotional facial animation creation. This ontology is made using Web Ontology Language and the results are presented as answered queries. Copyright © 2006 John Wiley & Sons, Ltd.
Curve skeleton skinning for human and creature characters
Authors: Yang Xiaosong , Somasekharan Arun , Zhang Jian J.
Published: June 2006

The skeleton driven skinning technique is still the most popular method for animating deformable human and creature characters. Albeit an industryde factodue to its computational performance and intuitiveness, it suffers from problems like collapsing elbow and candy wrapper joint. To remedy these problems, one needs to formulate the non‐linear relationship between the skeleton and the skin shape of a character properly, which however proves mathematically very challenging. Placing additional joints where the skin bends increases the sampling rate and is an ad hoc way of approximating this non‐linear relationship. In this paper, we propose a method that is able to accommodate the inherent non‐linear relationships between the movement of the skeleton and the skin shape. We use the so‐called curve skeletons along with the joint‐based skeletons to animate the skin shape. Since the deformation follows the tangent of the curve skeleton and also due to higher sampling rates received from the curve points, collapsing skin and other undesirable skin deformation problems are avoided. The curve skeleton retains the advantages of the current skeleton driven skinning. It is easy to use and allows full control over the animation process. As a further enhancement, it is also fairly simple to build realistic muscle and fat bulge effect. A practical implementation in the form of a Maya plug‐in is created to demonstrate the viability of the technique. Copyright © 2006 John Wiley & Sons, Ltd.
Tour into the picture with water surface reflection and object movements
Authors: Park Jinho , Heo Nambin , Choi Sunghee , Shin Sung Yong
Published: June 2006

Given a still picture, tour into the picture (TIP) generates a walk‐through animation of a 3D scene constructed from the picture. In this paper, we generalize TIP to deal with water surface reflection while allowing foreground objects to move. We formulate a non‐linear optimization problem to find the 3D scene parameters with respect to the camera position, to automatically construct a reasonable 3D scene model, provided with a set of points and their corresponding points on the water surface. To synthesize a stream of reflected images on the water surface in accordance with the camera movement, we propose a novel image‐based approach, which makes the best of the limited information available in the input picture. Furthermore, we incorporate water surface movement data acquired from water simulation on top of stochastic motion textures for objects such as trees and plants, to create a dynamic scene. Copyright © 2006 John Wiley & Sons, Ltd.
Temporal alignment of communicative gesture sequences
Authors: Heloir Alexis , Courty Nicolas , Gibet Sylvie , Multon Franck
Published: June 2006

In this paper we address the problem of temporal alignment applied to capture communicative gestures conveying different styles. We propose a representation space that may be considered asrobustto the spatial variability induced by style. By extending a multilevel dynamic time warping algorithm, we show how this extension can fulfil the goals of time correspondence between gesture sequences while preventing jerkiness introduced by standard time warping methods. Copyright © 2006 John Wiley & Sons, Ltd.
Interactive mesh deformation with pseudo material effects
Authors: Huang Jin , Zhang Hongxin , Shi Xiaohan , Liu Xinguo , Bao Hujun
Published: June 2006

This paper presents a novel interactive mesh deformation method that can achieve various dynamic material effects, including elastic membrane and cloth effects. In our framework, a mesh is encoded by some differential quantities based on edge length and dihedral angle; and the deformation is formulated as a least square problem for preserving the edge length and dihedral angle via the differential quantities. In order to obtain anisotropic material effects, we further propose an edge‐weighting scheme based on a user‐specified vector field. To avoid specifying the local transformations, we set up an iterative scheme for solving the deformation. At last, several examples are presented to show that our approach can interactively generate visually pleasing deformations. Copyright © 2006 John Wiley & Sons, Ltd.
Generating genus‐n‐to‐mmesh morphing using spherical parameterization
Authors: Lee Tong‐Yee , Yao Chih‐Yuan , Chu Hung‐Kuo , Tai Ming‐Jen , Chen Cheng‐Chieh
Published: June 2006

Surface parameterization is a fundamental tool in computer graphics and benefits many applications such as texture mapping, morphing, and re‐meshing. Many spherical parameterization schemes with very nice properties have been proposed and widely used in the past. However, it is well known that the spherical parameterization is limited to genus‐0models. In this paper, we first propose a novel framework to extend spherical parameterization for handling a genus‐n surface. In this framework, we represent a surface S of arbitrary genus by a positive mesh O and several negative meshes Ni. Each negative surface is used to represent a hole. A positive surface O is obtained by removing all holes in the original surface S. Then, both positive and negative meshes are genus‐0 and can be spherically parameterized, respectively. To compute S, we can use a Boolean difference operation to subtract negative Nifrom a positive O. Next, we apply this novel framework to generate genus‐n‐to‐m mesh morphing application without restriction of n = m. Finally, there are many interesting non‐genus‐0 mesh morphing sequences generated. Copyright © 2006 John Wiley & Sons, Ltd.
An integrated perception for autonomous virtual agents: active and predictive perception
Authors: Conde Toni , Thalmann Daniel
Published: June 2006

This paper presents an original model with methodologies that integrate in a novel way different types of an autonomous virtual agent's perception in a virtual environment. Our first new approach permits the coherent management of the shared virtual environment for the simulations of an autonomous virtual agent (AVA). Our second approach allows the prediction or the estimation of both the orientation and the attention of an AVA in a virtual environment. By means of a test application with a ‘virtual goalkeeper’, we demonstrate the speed and the robustness of our technique. Copyright © 2006 John Wiley & Sons, Ltd.
Realistic human hand deformation
Authors: Lee Jieun , Yoon Seung‐Hyun , Kim Myung‐Soo
Published: June 2006

We present a new approach to realistic hand modeling and deformation with real‐time performance. We model the underlying shape of a human hand by means of sweeps which follow a simplified skeleton. The resulting swept surfaces are blended, and an auxiliary surface is then bound to the swept representation in the palm region. In the areas of this palm‐control surface where bulges occur in certain poses of a real hand, the vertices are given their own trajectories, so that the palm forms realistic shapes as the joints bend. Palm lines can also be modeled as valleys in the skin by sketching them on a displacement map on the palm‐control surface, and activitating them when appropriate joint movements take place. Self‐intersections and collisions are detected using geometric primitives that are automatically generated from, and deform with, the sweeps and palm surface. Our algorithm runs in real time, and the naturalism of its results are demonstrated by comparative images of modeled and real hands, including several challenging poses. Copyright © 2006 John Wiley & Sons, Ltd.
Hair motion cloning from cartoon animation sequences
Authors: Sugisaki Eiji , Kazama Yosuke , Morishima Shigeo , Tanaka Natsuko , Sato Akiko
Published: June 2006

This paper describes a new approach to create cartoon hair animation that allows users to use existing cel character animation sequences. We demonstrate the generation of cartoon hair animation accentuated in ‘anime‐like’ motions. The novelty of this method is that users can choose the existing cel animation of a character's hair animation and apply environmental elements such as wind to other characters with a three‐dimensional structure. In fact, users can reuse existing cartoon sequences as input to endow another character with environmental elements as if both characters exist in the same scene. A three‐dimensional character's hair motions are created based on hair motions from input cartoon animation sequences. First, users extract hair shapes at each frame from input sequences from which they then construct physical equations. ‘Anime‐like’ hair motion is created by using these physical equations. Copyright © 2006 John Wiley & Sons, Ltd.
Facial shape and 3D skin
Authors: Lee Won‐Sook , Soon Andrew
Published: June 2006

We present novel ideas for facial shape and skin simulation on extremely detailed three‐dimensional facial meshes. Our input database is composed of a small number of scanned human faces with resolutions up to several million triangles, where even the pores are clearly distinguished. We show how to decompose the facial meshes into the global shape of the face plus skin detail (3D skin), and then to reconstitute them. Our modeling methodology allows us to simulate the exaggeration of the facial global shape, retaining the original skin detail, as well as to transfer 3D skin from one face to another. First, we represent all the input faces in terms of a homogeneous structure on the base model in low resolution by using mesh adaptation techniques. Second, the differences between the original mesh and a base mesh, which appear as skin detail, are captured and stored, so that each face is decomposed into the global shape (a base mesh) plus skin detail. Face reconstitution after global shape exaggeration and/or skin transfer enables delicate simulation of facial models. In addition, we can increase the resolution of any model scanned at a low resolution by transferring skin from a higher resolution model. Our method shows successful manipulation of the minute structure of 3D skin differently from other methods such as Normal Mapping, Displacement Mapping, Displaced Subdivision Surfaces, and Normal Meshes where none of these techniques show manipulation of minute structure like ours and only approximation is used while our method recovers the original structure. Copyright © 2006 John Wiley & Sons, Ltd.
Direct and Efficient Monitoring of Glycosyltransferase Reactions on Gold Colloidal Nanoparticles by Using Mass Spectrometry
Authors: Nagahori Noriko , Nishimura Shin‐Ichiro
Published: June 2006

A simple and efficient assay for glycosyltransferase activity on gold colloidal nanoparticles (GCNPs) by using laser desorption/ionization time‐of‐flight mass spectrometry (LDI‐TOF MS) is demonstrated by the enzymatic synthesis of the Lewis X trisaccharide on GCNPs containing GlcNAc residues. GCNPs containing multivalent sugars were well dispersed in aqueous solution and proved to be excellent acceptor substrates for the glycosyltransferase reaction. Direct LDI‐TOF MS analysis of these GCNPs provided the ion peaks of the sugar derivatives, chemisorbed through SAu linkages onto the GCNPs, even in the presence of contaminants such as proteins and salts. Thus, it enabled the rapid and direct detection of the enzymatic reaction on the GCNPs by subjecting a small amount (0.15 μL) of the reaction mixture to MS analysis without purification. Subsequent MS/MS analyses (LDI‐LIFT‐TOF/TOF method) of the product‐carrying GCNPs enabled the structures of the sugar derivatives that had been constructed on the GCNPs by enzymatic glycosylation to be determined. A quantitative inhibition assay for glycosyltransferase by using LDI‐TOF MS analysis on the GCNPs was demonstrated by using uridine 5′‐diphosphate (UDP) as the inhibitor. This simple assay was then applied to the detection of the enzymatic activity of a crude cell extract of Escherichia coli, which produces Neisseria meningitidis β‐1,4‐galactosyltransferase (β‐1,4‐GalT). In this case, the GCNPs were roughly purified by means of ultrafiltration to remove the buffer and detergents before MS analysis. That the GCNPs are dissolved in solution in the reaction medium but are solid in the purification process is greatly advantageous for the simple and efficient detection of enzymatic activity in crude biological samples. Thus, GCNPs containing a variety of biomolecules may become a versatile and efficient tool for the rapid and direct monitoring of metabolism (metabolomics) in living cells when combined with LDI‐TOF MS analysis.
A Bridge between Pillared‐Layer and Helical Structures: A Series of Three‐Dimensional Pillared Coordination Polymers with Multiform Helical Chains
Authors: Xiao Dong‐Rong , Wang En‐Bo , An Hai‐Yan , Li Yang‐Guang , Su Zhong‐Min , Sun Chun‐Yan
Published: June 2006

Rational self‐assembly of a long V‐shaped 3,3′,4,4′‐benzophenonetetracarboxylate (bptc) ligand and metal salts in the presence of linear bidentate ligand yield a series of novel pillared helical‐layer complexes, namely, [Cu2(bptc)(bpy)2] (1), [M3(Hbptc)2(bpy)3(H2O)4]⋅2 H2O (M = Fe(2) and Ni(3)), [Co2(bptc)(bpy)(H2O)]⋅0.5 bpy (4), [Cd2(bptc)(bpy)(H2O)2]⋅H2O (5), [Mn2(bptc)(bpy)1.5(H2O)3] (6) and [M2(bptc)(bpy)0.5(H2O)5]⋅0.5 bpy (M = Mn(7), Mg(8) and Co(9), bpy=4,4′‐bipyridine). Their structures were determined by single‐crystal X‐ray diffraction analyses and further characterized by elemental analyses, IR spectra, and thermogravimetric (TG) analyses. The structure of 1 consists of two types of chiral layers, one left‐handed and the other right‐handed, which are connected by bpy pillars to generate a novel 3D open framework featuring four distinct helical chains. Compounds 2 and 3 are isostructural and feature 3D structures formed from the interconnection of arm‐shaped helical layers with bpy pillars. Compound 4 is a pillared helical double‐layer complex containing four different types of helices, among which the nine‐fold interwoven helices constructed from triple‐stranded helical motifs are unprecedented. Compound 5 exhibits a novel 3D covalent framework which features nanosized tubular channels. These channels are built from helical layers pillared by bptc ligands. The structure of 6 is constructed from {Mn(bptc)(H2O)}n2n− layers, which consist of left‐ and right‐handed helical chains, pillared by [Mn2(bpy)3(H2O)4]4+ complexes into a 3D framework. To the best of our knowledge, compounds 1–6 are the first examples of pillared helical‐layer coordination polymers. Compounds 7–9 are isostructural and exhibit interesting 2D helical double‐layer structures, which are constructed from {M(bptc)(H2O)2}n2n− ribbons cross‐linked by [M2(bpy)(H2O)6]4+ complexes. Furthermore, the 3D supramolecular structures of 7–9 are similar to the 3D structure of 6, and the 2D structure of 7 can be transformed into the 3D structure of 6 at higher reaction temperature. By inspection of the structures of 1–9, it is believed that the V‐shaped bptc ligand and V‐shaped phthalic group of the bptc ligand are important for the formation of the helical structures. The magnetic behavior of compounds 1, 2, 4, 6, and 9 was studied and indicated the existence of antiferromagnetic interactions. Moreover, compound 5 shows intense photoluminescence at room temperature.
Zn(II)‐Selective Membrane Electrode Based on Tetraazamacrocycle [Bzo2Me2Ph2(16)hexaeneN4]
Authors: Singh Ashok Kumar , Jain Ajay Kumar , Saxena Puja , Mehtab Sameena
Published: June 2006

A PVC membrane electrode using [Bzo2Me2Ph2(16)hexaeneN4] (I) as ionophore, oleic acid as lipophilic additive and o‐nitrophenyloctyl ether as plasticizer has been investigated as Zn(II)‐selective electrode. The membrane incorporating 34.9% (w/w) PVC, 2.3% I, 4.7% OA and 58.1% o‐NPOE gave linear response over the concentration range 2.82×10−6−1.0×10−1 M with a Nernstian slope of 28.5±0.2 mV/decade of concentration with a detection limit of 2.24×10−6 M (0.146 ppm) and showed a response time of less than 10 s and could be used in pH range 2.5–8.5. High selectivity was obtained over a wide variety of metal ions. The proposed electrode was successfully used as an indicator electrode in potentiometric titration of zinc ions with EDTA and for determination of zinc in real samples.
High volume hydrodynamic injection of plasmid DNA via the hepatic artery results in a high level of gene expression in rat hepatocellular carcinoma induced by diethylnitrosamine
Authors: Tada Masaharu , Hatano Etsuro , Taura Kojiro , Nitta Takashi , Koizumi Naoki , Ikai Iwao , Shimahara Yasuyuki
Published: June 2006

Background

Hydrodynamic injection of naked plasmid DNA (pDNA) via the tail vein is a safe and effective method of gene transfer to the liver. However, successful gene transfer has yet to be shown for hepatocellular carcinoma (HCC); therefore, we investigated the feasibility and efficacy of hydrodynamic injection via the tail vein and hepatic artery in a diethylnitrosamine (DEN)‐induced HCC model in rats.

Methods

HCC was induced in Sprague‐Dawley rats by 100 ppm DEN in drinking water. pCMV‐SPORT‐β‐galactosidase (β‐gal, 400 µg) was injected (i) via the tail vein in a volume of 0.1 ml/g in 30 s or (ii) via the hepatic artery in a volume of 5 or 10 ml at 1 ml/s, either with or without temporary occlusion of the inferior vena cava (IVC) and portal vein (PV). The liver was harvested 24 h after administration, and β‐gal expression was evaluated with X‐gal staining and measurement of enzymatic activity in tissue homogenates.

Results

Hydrodynamic injection via the tail vein achieved transgene expression only in non‐cancerous tissue (tumor: 0.16 ± 0.04%, non‐tumor: 5.07 ± 1.66%). Hydrodynamic injection via the hepatic artery was tolerated, but failed to produce efficient transgene expression in tumor and non‐tumor cells. On the other hand, concomitant use of temporary IVC/PV occlusion with hydrodynamic injection via the hepatic artery dramatically increased transgene expression in cancer cells, but tumor‐selective gene transfer was not achieved with this procedure (tumor: 7.38 ± 3.66%, non‐tumor: 7.77 ± 1.06%).

Conclusions

High‐volume hydrodynamic injection of a pDNA solution via the hepatic artery with IVC/PV occlusion achieved a high level of gene expression in a HCC rat model. This gene transfer technique may have potential in clinical gene therapy for HCC. Copyright © 2006 John Wiley & Sons, Ltd.
Discrimination of wheat varieties by simultaneous measurements of oxygen consumption and consistency of flour dough during mixing
Authors: Levavasseur Loïc , Rakotozafy Lalatiana , Manceau Elise , Louarme Loïc , Robert Hugues , Baret Jean‐Luc , Potus Jacques , Nicolas Jacques
Published: June 2006

Using an instrumented mixing reactor, oxygen consumption and torque evolution were recorded during the mixing of wheat flour doughs from eight pure French wheat varieties harvested in 2002 and 2003. Wheat flours were also characterised by biochemical analyses including lipoxygenase (LOX) activity assay, free polyunsaturated fatty acid (PUFA) content, glutathione and ferulic acid contents, results of alveograph and farinograph tests and breadmaking performances. Some parameters defined from the obtained torque curves, equivalent to consistency curves, were correlated with alveograph and farinograph data. The importance of LOX activity levels and free PUFA content to explain the oxygen consumption during mixing is confirmed. In addition to the characteristics of the oxygen consumption curves, the extent to which the consistency curve parameters are able to differentiate among doughs made with flours from different wheat varieties is considered. Copyright © 2006 Society of Chemical Industry
Anthocyanin fingerprint of grapes: environmental and genetic variations
Authors: Ortega‐Regules Ana , Romero‐Cascales Inmaculada , López‐Roca Jose M , Ros‐García Jose M , Gómez‐Plaza Encarna
Published: June 2006

The anthocyanin content and fingerprint of four different Vitis vinifera L. varieties (Cabernet Sauvignon, Merlot, Syrah and Monastrell), the last grown in two different locations, were studied during three growing seasons to determine how seasonal conditions and location affect the content of berry anthocyanins and their relative percentages. Important differences in the content of anthocyanins were detected among varieties—Monastrell grapes from one of the locations presenting the highest anthocyanin content—when expressed as µg g−1 of skin. However, due to the large berry size of Monastrell grapes, when the results were expressed as mg kg−1 of berry, Cabernet Sauvignon and Syrah grapes presented the highest concentration. Significant differences were found as regards growing season, the concentration of anthocyanins being lowest in 2003, the warmest year. As regards the relative percentage of the different anthocyanins, substantial differences were found between varieties, but again, the results were also influenced by the year under study. When the percentages of anthocyanins were used as variables in a discriminant analysis, a 100% correct classification of the four different varieties was obtained. Moreover, to check the suitability of this tool for classifying varieties, data referring to the anthocyanin percentages of the four varieties grown in very different agroecological conditions and at different ripening stages were tested with the model we have built, 89% of correct classification being achieved. Copyright © 2006 Society of Chemical Industry
Analysis of secondary metabolites from eschscholtzia californica by high‐performance liquid chromatography
Authors: Klvana Maya , Chen Jingkui , Lépine François , Legros Robert , Jolicoeur Mario
Published: June 2006

A rapid and precise analytical HPLC method has been developed for screening the major benzophenanthridine alkaloids produced by cell cultures of Eschscholtzia californica, namely, sanguinarine, chelirubine, macarpine, chelerythrine and chelilutine. Separation was achieved on a C18 reversed‐phase column with gradient elution using acetonitrile and 50 mm phosphoric acid. Detection was performed by both fluorescence (λex 330 nm, λem 570 nm) and photodiode array, leading to good selectivity and precision in determining peak purity. A simple and quick sample preparation protocol was elaborated involving a methanolic extraction for the measurement of intracellular concentrations of the alkaloids and a solid phase extraction for their quantification in culture medium. Owing to the non‐availability of commercially standards, a method for the purification of chelirubine, macarpine and chelilutine by semi‐preparative HPLC was developed. Coupled together, the isolation method and the analytical method were highly reliable for screening the alkaloids of interest produced by E. californica. Copyright © 2006 John Wiley & Sons, Ltd.
Headspace–solid‐phase microextraction fast GC in combination with principal component analysis as a tool to classify different chemotypes of chamomile flower‐heads (Matricaria recutita L.)
Authors: Rubiolo Patrizia , Belliardo Flavio , Cordero Chiara , Liberto Erica , Sgorbini Barbara , Bicchi Carlo
Published: June 2006

Headspace–solid‐phase microextraction gas chromatography‐principal component analysis (HS‐SPME GC‐PCA) is proposed as a complementary or alternative method to essential oil (EO) GC‐PCA in order to discriminate between flower‐heads of chamomile of different chemotypes. Ninety‐two EOs and the headspaces sampled by HS‐SPME of the corresponding chamomile flower‐heads were examined by conventional GC and fast GC (F‐GC) and the results submitted to statistical analysis by PCA. HS‐SPME F‐GC‐PCA showed itself to be a rapid technique by which to distinguish chamomile flower‐head chemotypes a produced results in agreement with the accepted EO classification. Using this method, the analysis time was reduced from at least 4.5 h with EO conventional GC to less than 1 h with HS‐SPME F‐GC. This approach can thus successfully be used as an analytical decision maker in order to reduce the number of time‐consuming EO conventional GC analyses by limiting them to those samples that cannot unequivocally be classified. The EO conventional GC and HS‐SPME F‐GC results of PCA were very uniform, but they did not provide quantitative correlations between the components as determined by the two methods. A different statistical approach and a larger number of samples will be needed in order to correlate components in the headspace sampled by SPME and those in the corresponding EO quantitatively through a function. Copyright © 2006 John Wiley & Sons, Ltd.
Retracted: Effect of Meso‐dihydroguaiaretic acid from Machilus thunbergii Sieb et Zucc on MMP‐1 expression in heat shock‐induced cultured primary human fibroblasts
Authors: Moon Hyungin , Jung Jae‐Chul
Published: June 2006

This article has been retracted. See retraction notice DOI: 10.1002/ptr.2151

Ethanol and aqueous extracts of Machilus thunbergii Sieb et Zucc (Lauraceae) used traditionally for the treatment of a variety of diseases were screened in vitro for MMP‐1 inhibitory actions. Meso‐dihydroguaiaretic acid (MDGA) from the stem bark of M. thunbergii showed a significant inhibition of matrix metalloproteinase (MMP)‐1 in primary human fibroblasts by heat shock‐induced. This study investigated the effect of MDGA isolated from M. thunbergii on heat shock‐induced premature skin aging. MDGA reduced the expression of MMP‐1 at the protein level in a dose‐dependent manner in heat shock‐induced cultured primary human fibroblasts. Taken together, these results show that MDGA can prevent the harmful effects of heat (and/or IR) that lead to skin aging. Copyright © 2006 John Wiley & Sons, Ltd.
QSTR with Extended Topochemical Atom (ETA) Indices 8.aQSAR for the inhibition of substituted phenols on germination rate ofCucumis sativususing chemometric tools
Authors: Roy Kunal , Ghosh Gopinath
Published: June 2006

Quantitative structure‐toxicity relationship (QSTR) study has proved to be a valuable approach in ecotoxicity estimations of acute and chronic toxicity to various organisms, and in fate estimations of physical/chemical properties, degradation, and bioconcentration. In this background, we have modeled the inhibition of 41 substituted phenols on germination rate ofCucumis sativuswith extended topochemical atom (ETA) indices using different chemometric tools and compared the ETA relations with non‐ETA models derived from different topological indices (WienerW, BalabanJ, HosoyaZ, Zagreb, molecular connectivity indices, E‐state indices and kappa shape indices) and physicochemical parameters (AlogP98, MolRef, H_bond_acceptor, H_bond_donor, MW,logKowand Elumo). Different statistical tools used in this communication are stepwise regression analysis, multiple linear regression with factor analysis as the preprocessing step for variable selection (FA‐MLR), multiple linear regression with genetic function approximation (GFA‐MLR), partial least squares regression with factor analysis as the preprocessing step for variable selection (FA‐PLS), genetic partial least squares (G/PLS) and principal component regression analysis (PCRA). The results show that the best statistical quality along with prediction statistics with ETA descriptors is found in case of GFA‐MLR equation. In case of non‐ETA descriptors, the best equation is obtained from PCRA considering both equation statistics and predictive ability. When combined descriptors were considered, FA‐PLS gave the best equation. The best ETA equation (GFA‐MLR) has better leave‐one‐outQ2value than the best non‐ETA equation (PCRA). The results suggest that the ETA descriptors are sufficiently rich in chemical information to encode the structural features contributing significantly to the comparative inhibition activity of substituted phenols on germination rate ofCucumis sativus.
Liquid chromatography/tandem mass spectrometry method for simultaneous determination of risperidone and its active metabolite 9‐hydroxyrisperidone in human plasma
Authors: Bhatt Jignesh , Subbaiah Gunta , Singh Sadhana
Published: June 2006

A rapid and sensitive liquid chromatography/tandem mass spectrometry (LC/MS/MS) method has been developed and validated for simultaneous quantification of risperidone (RSP) and its active metabolite 9‐hydroxyrisperidone (9‐OH‐RSP) in human plasma. The analytes were extracted from human plasma by using the protein precipitation extraction technique. Methyl risperidone was used as internal standard for RSP and 9‐OH‐RSP. A Betasil C18 column provided chromatographic separation of analytes followed by detection with mass spectrometry. The mass transition ion‐pair was followed as m/z 411.28 → 191.15 for RSP and m/z 427.30 → 207.10 for 9‐OH‐RSP. The method involves a simple extraction, isocratic chromatography conditions and mass spectrometric detection that enable detection at sub‐nanogram levels. The proposed method has been validated with a linear range of 0.10–15.0 ng/mL for RSP and 9‐OH‐RSP. The intrarun and interrun precision and accuracy values were within 15%. The overall recoveries for RSP and 9‐OH‐RSP were 82.1% and 83.2%, respectively. The total analysis time was as low as 3.0 min only. The developed method was applied for the determination of the pharmacokinetic parameters of RSP and 9‐OH‐RSP following a single oral administration of a 1 mg RSP tablet in 24 healthy male volunteers. Copyright © 2006 John Wiley & Sons, Ltd.
Study of polybrominated diphenyl ethers using both positive and negative atmospheric pressure photoionization and tandem mass spectrometry
Authors: Riu Anne , Zalko Daniel , Debrauwer Laurent
Published: June 2006

Atmospheric pressure photoionization (APPI) was assessed for the mass spectrometric analysis of polybromodiphenyl ethers (PBDEs) on the basis of a set of 17 standard compounds. Positive and negative ionization modes were both investigated. M+. ions were formed under positive ion conditions whereas the negative ion mode yielded [M–Br+O]− ions. The behavior of these APPI‐produced ions towards collisional activation was studied using an ion trap mass spectrometer. In positive ion mode, the loss of Br2 was one of the major fragmentation pathways, and was favored for ortho‐substituted PBDEs. Conversely, the loss of COBr. occurred only for non‐ortho‐substituted congeners. The collisional excitation of [M–Br+O]− ions in the ion trap also led to the loss of Br2, to the elimination of HBr, and to the formation of product ions by cleavage of the ether bond. The formation of para‐quinone radical anions was observed for PBDEs ranging from penta‐ to hepta‐congeners, whereas brominated aromatic carbanions were formed preferentially for the most brominated PBDEs studied in this work (hepta‐ or deca‐BDEs). M+. ions did not undergo this fragmentation process. Copyright © 2006 John Wiley & Sons, Ltd.
Determination of gabapentin in human plasma using hydrophilic interaction liquid chromatography with tandem mass spectrometry
Authors: Ji Hye Young , Jeong Dong Won , Kim Young Hoon , Kim Hui‐Hyun , Yoon Yoo‐Seok , Lee Kang Choon , Lee Hye Suk
Published: June 2006

A rapid, sensitive and selective method for the determination of gabapentin in human plasma was developed using hydrophilic interaction liquid chromatography/tandem mass spectrometry (HILIC/MS/MS). The devised method involved protein precipitation with acetonitrile followed by separation on an Atlantis HILIC silica column using an acetonitrile/ammonium formate mobile phase (100 mM, pH 3.0) (85:15, v/v). Analytes were detected using an electrospray ionization mass spectrometer in the multiple‐reaction monitoring mode. The standard curve was linear (r = 1.000) over the concentration range of 50.0–10000 ng/mL. The lower limit of quantification for gabapentin was 50.0 ng/mL (ca. 20 pg gabapentin) using a 10‐µL plasma sample. The coefficients of variation and relative errors for intra‐ and inter‐assay at four QC levels (i.e., 50.0, 125, 750, and 7500 ng/mL) were 4.7 to 9.4% and −4.1 to 1.6%, respectively. Absolute and relative matrix effects for gabapentin and metformin were practically absent. Gabapentin and metformin recoveries were 98.5% and 99.0%, respectively. This method was successfully applied to a bioequivalence study of gabapentin in humans. Copyright © 2006 John Wiley & Sons, Ltd.
Recognition of GPCRs by Peptide Ligands and Membrane Compartments theory: Structural Studies of Endogenous Peptide Hormones in Membrane Environment
Authors: Sankararamakrishnan Ramasubbu
Published: June 2006

One of the largest family of cell surface proteins, G-protein coupled receptors (GPCRs) regulate virtually all known physiological processes in mammals. With seven transmembrane segments, they respond to diverse range of extracellular stimuli and represent a major class of drug targets. Peptidergic GPCRs use endogenous peptides as ligands. To understand the mechanism of GPCR activation and rational drug design, knowledge of three-dimensional structure of receptor–ligand complex is important. The endogenous peptide hormones are often short, flexible and completely disordered in aqueous solution. According to “Membrane Compartments Theory”, the flexible peptide binds to the membrane in the first step before it recognizes its receptor and the membrane-induced conformation is postulated to bind to the receptor in the second step. Structures of several peptide hormones have been determined in membrane-mimetic medium. In these studies, micelles, reverse micelles and bicelles have been used to mimic the cell membrane environment. Recently, conformations of two peptide hormones have also been studied in receptor-bound form. Membrane environment induces stable secondary structures in flexible peptide ligands and membrane-induced peptide structures have been correlated with their bioactivity. Results of site-directed mutagenesis, spectroscopy and other experimental studies along with the conformations determined in membrane medium have been used to interpret the role of individual residues in the peptide ligand. Structural differences of membrane-bound peptides that belong to the same family but differ in selectivity are likely to explain the mechanism of receptor selectivity and specificity of the ligands. Knowledge of peptide 3D structures in membrane environment has potential applications in rational drug design.