bluuebunny/crossref_metadata_2025 huggingface dataset:
Hexyl‐aminolevulinate‐mediated photodynamic therapy: How to spare normal urothelium. An in vitro approach
Authors: Vaucher Laurent , Jichlinski Patrice , Lange Norbert , Ritter‐Schenk Céline , van den Bergh Hubert , Kucera Pavel
Published: November 2006

Background and Objectives

Photodynamic therapy (PDT) of superficial bladder cancer may cause damages to the normal surrounding bladder wall. Prevention of these is important for bladder healing. We studied the influence of photosensitizer concentration, irradiation parameters, and production of reactive oxygen species (ROS) on the photodynamically induced damage in the porcine urothelium invitro. The aim was to determine the threshold conditions for the cell survival.

Methods

Living porcine bladder mucosae were incubated with solution of hexylester of 5‐aminolevulinic acid (HAL). The mucosae were irradiated with increasing doses and cell alterations were evaluated by scanning electron microscopy and by Sytox green fluorescence. The urothelial survival score was correlated with Protoporphyrin IX (PpIX) photobleaching and intracellular fluorescence of Rhodamine 123 reflecting the ROS production.

Results

The mortality ratio was dependent on PpIX concentration. After 3 hours of incubation, the threshold radiant exposures for blue light were 0.15 and 0.75 J/cm2 (irradiance 30 and 75 mW/cm2, respectively) and for white light 0.55 J/cm2 (irradiance 30 mW/cm2). Photobleaching rate increased with decreasing irradiance. Interestingly, the DHR123/R123 reporter system correlated well with the threshold exposures under all conditions used.

Conclusions

We have determined radiant exposures sparing half of normal urothelial cells. We propose that the use of low irradiance combined with systems reporting the ROS production in the irradiated tissue could improve the in vivo dosimetry and optimize the PDT. Lasers Surg. Med. © 2006 Wiley‐Liss, Inc.
Ex vivo imaging of chronic total occlusions using forward‐looking optical coherence tomography
Authors: Munce Nigel R. , Yang Victor X.D. , Standish Beau A. , Qiang Beiping , Butany Jagdish , Courtney Brian K. , Graham John J. , Dick Alexander J. , Strauss Bradley H. , Wright Graham A. , Vitkin I. Alex
Published: November 2006

Background and Objectives

Percutaneous coronary interventions (PCI) of chronic total occlusions (CTOs) of arteries are more challenging lesions to treat with angioplasty and stenting than stenotic vessels due primarily to the difficulty in guiding the wire across the lesion. Angiography alone is unable to differentiate between the occluded lumen and the vessel wall and to characterize the content of the occlusion. New technologies to aid in interventional guidance are therefore highly desirable. We sought to evaluate tissue characterization in arterial (CTOs) by imaging ex vivo peripheral arterial samples with optical coherence tomography (OCT).

Study Design/Materials and Methods

Ex vivo arterialsamples were obtained from patients undergoing peripheral limb amputation. Samples were imaged in an enface orientation using an OCT system, enabling sequential acquisition of longitudinal images and volumetric reconstruction of cross‐sectional views of theoccluded arteries. Histology was performed for comparison.

Results

OCT imaging reliably differentiated between the occluded lumen and the underlying arterial wall in peripheral CTOs. OCT correctly identified tissue composition within the CTO, such as the presence of collagen and calcium and was also able to identify intraluminal microchannels.

Conclusions

OCT imaging of CTO anatomy and tissue characteristics may potentially lead to substantial improvements in PCI interventions by providing novel guiding capabilities. Lasers Surg. Med. © 2006 Wiley‐Liss, Inc.
Preparation and Properties of Polystyrene/SEBS Blends with Compositional Gradients in Their Sheet Direction
Authors: Agari Yasuyuki , Yamamoto Taichi , Nomura Ryoki
Published: November 2006

There have been a few reports that discussed polymer blends with compositional gradient in their sheet directions. Thus, we discussed the preparation of the graded polystyrene(PS)/styrene‐hydorogenated butadiene‐ styrene block copolymer(SEBS) blend with compositional gradient in their sheet directions, by applying of the solution‐diffusion method. Then, the hardness on the air side surface of the graded blend gradually increased with shifting the measured point from the edge containing lowest PS content. All of the areas, into which the graded blend sheet was divided, were almost equal in length, when total elongation was 6.6 mm. However, the length of the area became longer at the larger SEBS content, when the total elongation was 175 mm. The ratio of the length of the area to that in lowest SEBS content increased gradually with increasing of SEBS content, when the total elongation became over 50 mm. It was considered that this phenomenon occurred, because of the compositional gradient in the PS/SEBS graded blend.
Synthesis of Low Dielectric Constant Polyetherimide Films
Authors: Chen Bor‐Kuan , Fang Yu‐Ting , Cheng Jing‐Ru
Published: November 2006

As the demand for downsizing in microelectronics is increasing, devices require material with lower dielectric constant accordingly. The dielectric constants for most polyimide (PI), including polyetherimide (PEI), films are ∼3.5. In this study, we modified the PEI by incorporating various monomers (fluorinated dianhydride 6FDA and phenylene ether diamines) to reduce the dielectric constant. The dielectric constants of synthesized PEIs decreased with increasing amounts of 6FDA content and phenylene ether units. The Tg decreased gradually with PEI containing longer phenylene ether units, but increased with the content of 6FDA. The thermal decomposition temperatures at 10% weight loss were ∼550 °C, indicating that these PEIs have high thermal stability. Both the tensile strength and the modulus decreased with the PEI containing longer phenylene ether units. The PEI synthesized with 40% 6FDA dianhydride and 1,4‐bis(4‐aminophenoxy)benzene (pBAB) diamine has the lowest dielectric constant of 2.78 at 1 MHz.
Supramolecular Structure of N,N‐Bis(2‐hydroxy‐benzyl)alkylamine: From Hydrogen Bond Assembly to Coordination Network in Guest Acceptance
Authors: Phongtamrug Suttinun , Chirachanchai Suwabun , Tashiro Kohji
Published: November 2006

N,N‐Bis(2‐hydroxybenzyl)alkylamine (HBA) was described as a model to simplify the supramolecular system of polybenzoxazines. The single crystal X‐ray analysis revealed that HBA forms a dimeric assembly based on its simultaneous inter‐ and intramolecular hydrogen bond network. When the HBA accepted the copper ion, the dimeric assembly HBA changed its primary hydrogen bond network to charge transfer coordination as clarified by the single crystal analysis as well as the superimposed structure based on DMol3 calculation. The supramolecular structure of HBA and copper also exhibited the role of solvent molecules in the packing structure which is a rare example showing the host accepts not only the metal ions but also the neutral molecules in the same time. The cyclization of HBA with esters or ethers to macrocyclic compounds was also an important model reaction to show how the backbone molecules self‐stabilized with the hydrogen bond network initiate the simple, effective and efficient macrocyclic reaction.
Paclitaxel‐Warfarin Interaction in Solution
Authors: Wunderlich Stefan , Zähres Manfred , Jo Byung‐Wook , Hess Michael
Published: November 2006

Interactions of a water‐soluble paclitaxel‐polymer conjugate were investigated in aqueous buffer solutions and in the solid state in the presence of model proteins that are abundant in blood serum (bovine serum albumin and human serum albumin). Studies of the intrinsic fluorescence of albumins and extrinsic fluorescence of the albumin/warfarin complex and MALDI‐TOF spectra proved significant interactions of the drug conjugate with the model proteins and warfarin.
RTL Investigation on the Radiochemical Oxidation of Polyolefins
Authors: Jipa Silviu , Zaharescu Traian , Kappel Wilhelm , Setnescu Radu , Oros Cǎlin
Published: November 2006

High energy radiation causes deep modification of exposed polymers. In the irradiated polymers, the main macroscopic process is the formation of free radicals. The “cooled” electron distribution at the temperature of liquid nitrogen will develop the existence of various electron gaps with certain depths by smooth heating up to room temperature. In this paper, low density polyethylene, high density polyethylene and polypropylene were subjected to the action of gamma rays for causing structural modifications. The glow curves of quantum emission were recorded by slow heating from 106 to 286 K. The characteristic shoulders were obtained, which were ascribed to various electron traps consisting of unsaturation or carbonyl groups. For depicting the influence of molecular structures, the influence of CH3 number/100 carbon atoms on the intensity of radiothermoluminescence (RTL) signal was studied on three types of LDPEs. A sharp decrease of maximum RTL intensity at advanced branching was pointed out. A mechanism of RTL emission is based on the present measurements.
Crystal Transformation and Development of Tensile Properties upon Drawing of Poly(L‐lactic acid) by Solid‐State Coextrusion: Effects of Molecular Weight
Authors: Sawai Daisuke , Yokoyama Takafumi , Kanamoto Tetsuo , Sungil Moon , Hyon Suong‐Hyu , Myasnikova Liuba P.
Published: November 2006

Melt‐crystallized films of poly(L‐lactic acid) (PLLA) with Mv in the range of 3.8 ∼ 46 × 104 consisting of α‐form crystals were uniaxially drawn by solid‐state coextrusion. The effects of Mv, extrusion draw ratio (EDR), and extrusion temperature (Text) on the crystal/crystal transformation from α‐ to β‐form crystals and the resultant tensile properties of drawn products were studied. The crystal transformation proceeded with EDR and more rapidly for the higher Mv's. Furthermore, the crystal transformation proceeded most rapidly with EDR at a Text around 130 °C, independently of the Mv's. As a result of the optimum combination of processing variables influencing the the crystal transformation (Mv, Text, and drawability), highly oriented films consisting of β‐form crystals alone were obtained by coextrusion of higher Mv samples at Text's slightly below the melting temperature (150 ∼ 170 °C) and at higher EDR's > 11. Both the tensile modulus and strength increased rapidly with EDR. The modulus at a given EDR was slightly higher for the samples with higher Mv's. In contrast, the strength at a given EDR was remarkably higher for the higher M
v's. The highest tensile modulus of 8.0 GPa and strength of 500 MPa were obtained with the sample of the highest Mv of 46 × 104 coextruded at 170 °C to the highest EDR of 14.
Re‐examination of the Reactivity of N‐Carboxy Amino Acid Anhydrides 1. Polymerisation of Amino Acid NCAs in Acetonitrile and in the Solid State in Hexane
Authors: Kanazawa Hitoshi , Inada Aya , Kawana Nobukazu
Published: November 2006

Ring‐opening polymerisation of N‐carboxy anhydrides of γ‐benzyl‐L‐ glutamate, L‐alanine and L‐leucine by a primary amine initiator in acetonitrile and in hexane was examined, with care taken to avoid contamination by moisture. The polymerisation of amino acid NCAs initiated by butylamine in hexane proceeded in the crystalline state (solid state) because the NCA crystals did not dissolve in hexane. Although amino acid NCAs were believed to polymerise completely in acetonitrile, polymerisation of the amino acid NCAs in acetonitrile was found to stop at around 20% conversion. As resulting polypeptides did not dissolve in acetonitrile, the polymer terminals were considered to be occluded in the polymer precipitate. On the other hand, each amino acid NCA was much more reactive in the solid state in hexane than in acetonitrile. Especially, L‐leucine NCA showed remarkable reactivity in the solid state. The reactivity in the solid state was explained with reference to the crystal structure.
Structural and Dynamical Properties of n‐Alkane Molecules in Clathrate Phase of Syndiotactic Polystyrene
Authors: Kaneko Fumitoshi , Uda Yukihiro , Kawaguchi Tatsuya , Ute Koichi , Yamamuro Osamu
Published: November 2006

Syndiotactic polystyrene (sPS) forms a clathrate phase with a variety of compounds. Not only rigid molecules but also flexible molecules can be stored in the cavities of the clathrate phase. To clarify the adjustment mechanism of a flexible guest molecule to the sPS clathrate system, the host and guest structures were investigated by means of solid‐state 13C NMR and Raman spectroscopy, and X‐ray diffractometry for the sPS clathrates with a series of n‐alkanes from n‐hexane to n‐decane. Although the 010 spacing of the host sPS lattice expanded slightly on going from n‐hexane to n‐heptane, it decreased markedly at n‐octane and then increased gradually with the chain length of guest n‐alkane. The conformational change of guest n‐alkane molecules was involved in this anomalous change in the 010 spacing. Majority of the n‐hexane and n‐heptane molecules took extended chain structures in the clathrates, whereas all longer n‐alkanes took bent chain structures. The mean‐square displacement of hydrogen atoms in the clathrates was estimated by quasielastic neutron scattering experiments. It was confirmed that the host lattice contraction suppressed thermal motion of the clathrate system.
Melting Processing of Biodegradable Cellulose Diacetate/Starch Composites
Authors: Lee S. Y. , Cho M. S. , Nam J. D. , Lee Y.
Published: November 2006

Natural polymers and their derivatives are attracting increasing interest as promising biodegradable materials that can meet the environmental and recycling demands from society. This study prepared biodegradable composites of cellulose diacetate and starch, and examined their physical and thermal properties. In addition, the morphology of the composites was examined by scanning electron microscopy. For melt processing, epoxidized soybean oil, as a lubricant, and triacetine, as a plasticizer, were added to the composites. The optimal conditions for the preparation of the biodegradable composites were determined. Increasing the amount of starch in the composites resulted in further enhancement of the processability of cellulose diacetate. The tensile strength and Young's modulus decreased, and the amount of elongation and Tg value increased with increasing amount of starch.
Interpenetrating Polymer Networks with Spatially Graded Morphology Controllable by UV‐Radiation Curing
Authors: Nakanishi Hideyuki , Namikawa Nobuhiro , Norisuye Tomohisa , Tran‐Cong‐Miyata Qui
Published: November 2006

Interpenetrating Polymer Networks (IPNs) composed of polystyrene (PS) and poly(methyl methacrylate) (PMMA) were synthesized from a precursor mixture by using dissimilar photo‐cross‐link reactions. When the reation yields exceeded a certain threshold, the mixture was quenched from one‐phase region into two‐phase region, leading to phase separation. Upon irradiation with strong UV‐light, an intensity gradient was formed along the propagating direction of the exciting light, generating a gradient of quench depth via the spatial inhomogeneity of the cross‐link reactions. As a consequence, a gradient of the characteristic length scales was continuously generated from the top to the bottom of the mixture. The resulting three‐dimensional (3‐D) morphology was in‐situ observed at different depths of the mixture by using a laser‐scanning confocal microscope (LSCM). From this 3‐D observation, it was found that phase separation was accelerated at the bottom of the mixture and proceeded in an autocatalytic fashion. The mechanism for the formation of the graded morphology was discussed in conjunction with the kinetics of the autocatalytic phase separation.
Ultrafast Optical Responsive SWNT/Polymer Thin Films in Guided Wave Mode Geometry
Authors: Ryu Jang‐Hyun , Nagamura Toshihiko , Shigeta Masahiro , Nakashima Naotoshi
Published: November 2006

Single walled carbon nanotubes (SWNT) having good optical and electrochemical properties were solublized by aromatic polymers. The polymer‐wrapped SWNT film cast from solution showed transient bleaching with a time constant of recovery less than 1 ps in both the visible and optical telecommunication wavelength region. Polymer thin film containing SWNT was assembled into the guided wave mode geometry with a low refractive index polymer.
Curing of Styrene‐Free Unsaturated Polyester Alkyd and Development of Novel Related Clay Nanocomposites
Authors: Mironi‐Harpaz I. , Narkis M. , Siegmann A.
Published: November 2006

Thermoset unsaturated polyesters (UP) are usually obtained by crosslinking of alkyd chains dissolved in an unsaturated reactive monomeric diluent, usually styrene. Recently we found that UP‐alkyd chains (without styrene) are intrinsically cured into a crosslinked matrix in the presence of peroxide. The thermal, mechanical, dynamic mechanical and chemorheological properties and the network molecular structure of the crosslinked UP‐alkyd are a function of the peroxide content used. All properties change considerably upon the addition of small amounts of peroxide (between 1 and 2%wt.) and change to a lesser extent upon employing higher peroxide concentrations (up to 6%wt.). Due to co‐occurrence of crosslinking and scission events, the crosslinked system contains both gel and sol fractions. The sol fraction demonstrates a plasticizing effect on the crosslinked network, affecting the thermal and mechanical properties of the crosslinked polymer. The new materials developed in this work are interesting for utilization in innovative styrene‐free UP‐alkyd/organo‐clay nanocomposites. It was found that inducing high shear levels for prolonged durations promotes the intercalation and exfoliation of the silicate layers, resulting in a better dispersion of clay particles. Crosslinking of the UP‐alkyd/organo‐clay nanocomposites alters their nanostructure, particularly affected by the peroxide content used. Thus, depending on the content employed, either an exfoliated or a combined intercalated/exfoliated structure may be realized.
Ultrasonic Investigation of the Gelation Process of Poly(Acrylamide) Gels
Authors: Norisuye Tomohisa , Strybulevych Anatoliy , Scanlon Martin , Page John
Published: November 2006

The time evolution of ultrasonic velocity and attenuation has been investigated in‐situ during the gelation process of polyacrylamide (PAAm) hydrogels. Longitudinal ultrasonic pulses were transmitted through the gel samples and continuously recorded to obtain the magnitude and phase of the waves as a function of time and frequency, enabling the attenuation coefficient, α, and phase velocity, vp, of PAAm gels to be determined. The reaction was characterized by (1) an initial rapid increase in α and vp, and (2) a subsequent reduction after both quantities passed through a peak associated with the exothermic reaction for the PAAm gelation. The square of vp is proportional to the longitudinal modulus of the sample and inversely proportional to the density, and the values of vp for the aged gels were smaller than those before the gelation. The cross‐linker concentration dependence was further examined in order to investigate the gelation process accompanied by phase separation.
Measurement System for Very Small Photoelastic Constant of Polymer Films
Authors: Tsukiji Mitsuo , Kowa Hiroyuki , Muraki Kanae , Umeda Norihiro , Imoto Kenji , Kanasaki Masayoshi , Tahara Komei , Morii Katsunori , Tajitsu Yoshiro
Published: November 2006

We produced a new system for measuring the small photoelastic constant of a polymer thin film with a small birefringence. Using our mesurement system, we evaluated the photoelastic constant of a polymer film in real time by quantitative analysis. Photoelastic constants of 11.30 × 10−12 Pa−1 for a cellulose triacetate film and 78.38 × 10−12 Pa−1 for a polycarbonate film were obtained. Furthermore, we obtained a small photoelastic constant of 0.12 × 10−12 Pa−1 for a cycloolefin film for liquid crystal displays, using our new measurement system. This value is very small. We emphasize that, if a small change in retardation and stress cannot be detected simultaneously using our system, then we cannot obtain such a small photoelastic constant.
Dynamical Mechanical Analysis and Curing Analysis of Fouling Release Coatings and Components
Authors: Provder Ted , Malliprakash Shyam , Amin Sarjak Hemantkumar , Majid Atheer , Texter John
Published: November 2006

A commercially available fouling release (adsorbed foulants removed by shear flow) coating based on poly(dimethylsiloxane) and a commercial marine epoxy primer have been analyzed by diffusing wave spectroscopy and by thermal and dynamical mechanical methods. Diffusing wave spectroscopy reveals 7–9 distinct relaxation intervals over short (minutes) to long (20 hour) time scales. Several junctures of these intervals are shown to correlate with mechanically determined film formation parameters, such as set to touch times, tack free times, and dry through times. Thickness series of coatings made by casting illustrate similarities and distinct differences between the epoxy primer and poly(dimethylsiloxane)‐based fouling release coating formulations. Several low temperature β transitions are resolved in the fouling release coatings in addition the α (Tg) transition in both formulations. A scaling analysis of the thickness series data shows that both the primer and the top coat exhibit a negative exponent for thickness; −0.77 for the epoxy; −1.2 for the top coat. Stress‐strain experiments reveal further significant difference between these two types of elastomers. The elastic modulus for the epoxy is 1000‐fold higher than for the topcoat. A small elastic modulus is thought to be key in the successful functioning of fouling release coatings. Analyses of substrate effects (wire mesh, fiberglass braid) and of coating or loading levels on dynamical mechanical properties, in comparison with thickness series of thin films are presented. The woven braid offers the advantage that it can be loaded more easily than can wire mesh substrates. The negative exponents show that thinner coatings may be more mechanically resilient than thicker coatings, as the ability to store and dissipate mechanical energy decreases as thickness increases.
Self‐Assembly and Liquid Crystalline Properties of Ionic Polymers and Their Nonionic Family
Authors: Yoshimi Takeshi , Ujiie Seiji
Published: November 2006

Langmuir‐Blodgett (LB) monolayers with an extremely dense azobenzene moiety in a unit area, were prepared using a series of ionic liquid crystalline polymers (ILCPs) and their nonionic family (NLCPs). The isober curves and the compression‐expansion isotherms of the ILCPs and NLCPs on water showed that the polymer Langmuir monolayers have good quality. The molecular organization of these polymers on the water surface depended on the length of spacer alkyl chains and the existence of ammonium salts. Low‐molecular‐weight liquid crystals between the LCP monolayer dipped glass substrates showed a homeotropic alignment.
Search of Optimum Conditions for Sublimation Growth of Thiophene/Phenylene Co‐Oligomer Crystals
Authors: Yamao Takeshi , Kawasaki Yasuhiro , Ota Satoshi , Hotta Shu , Azumi Reiko
Published: November 2006

Optimum crystal growth conditions of thiophene/phenylene co‐oligomers (TPCOs) have been studied by means of sublimation recrystallization method with changing both gas flow rate and gas pressure. The largest flaky crystal, more than 10 mm2, was produced at the gas flow rate ∼50 ml/min and reduced pressure ∼0.05 Mpa, while no crystals were obtained at pressure less than 0.01 MPa. Excess supply of N2 gas or reduced pressure for accelerating sublimation might obstruct the crystal growth of TPCOs.
Increased proximal urethral sensory threshold after radical pelvic surgery in women
Authors: Kessler Thomas M. , Studer Urs E. , Burkhard Fiona C.
Published: November 2006

Aim

To identify factors that potentially influence urethral sensitivity in women.

Patients and Methods

The current perception threshold was measured by double ring electrodes in the proximal and distal urethra in 120 women. Univariate analysis using Kaplan–Meier models and multivariate analysis applying Cox regressions were performed to identify factors influencing urethral sensitivity in women.

Results

In univariate and multivariate analysis, women who had undergone radical pelvic surgery (radical cystectomy n = 12, radical rectal surgery n = 4) showed a significantly (log rank test P < 0.0001) increased proximal urethral sensory threshold compared to those without prior surgery (hazard ratio (HR) 4.17, 95% confidence interval (CI) 2.04–8.51), following vaginal hysterectomy (HR 4.95, 95% CI 2.07–11.85), abdominal hysterectomy (HR 5.96, 95% CI 2.68–13.23), or other non‐pelvic surgery (HR 4.86, 95% CI 2.24–10.52). However, distal urethral sensitivity was unaffected by any form of prior surgery. Also other variables assessed, including age, concomitant diseases, urodynamic diagnoses, functional urethral length, and maximum urethral closure pressure at rest had no influence on urethral sensitivity in univariate as well as in multivariate analysis.

Conclusions

Increased proximal but unaffected distal urethral sensory threshold after radical pelvic surgery in women suggests that the afferent nerve fibers from the proximal urethra mainly pass through the pelvic plexus which is prone to damage during radical pelvic surgery, whereas the afferent innervation of the distal urethra is provided by the pudendal nerve. Better understanding the innervation of the proximal and distal urethra may help to improve surgical procedures, especially nerve sparing techniques. Neurourol. Urodynam. 26:208–212, 2007. © 2006 Wiley‐Liss, Inc.
A multi‐term semi‐energy finite strip method for post‐buckling analysis of composite plates
Authors: Assaee H. , Ovesy H. R.
Published: November 2006

In this paper a finite strip approach based on the concept of a rigorous post‐buckling solution for composite plates, namely the semi‐energy approach, is presented. Moreover, in semi‐energy finite strip approach, the out‐of‐plane displacement field of the finite strip is the only displacement which is postulated by a deflected form. The postulated deflected form is substituted into von Kármán's compatibility equation which is solved exactly to obtain the corresponding forms of the mid‐plane stresses and displacements. The solution of von Kármán's compatibility equation and the postulated out‐of‐plane deflected form are then used to evaluate the potential energy of the related finite strip. Finally, by invoking the principle of minimum potential energy, the equilibrium equations of the finite strip are derived. The developed finite strip method (FSM) is applied to analyse the post‐buckling behaviour of laminated composite plates. As far as, the validity and numerical efficiency of the developed semi‐energy FSM is concerned, the results obtained from semi‐energy FSM approach are compared with those obtained from a fairly conventional and well exploited finite strip technique, namely the full‐energy finite strip method. The study of the results revealed that the developed semi‐energy FSM provides a very higher convergence and stress distribution properties in comparison with the full‐energy solution by incorporating considerably less number of degrees of freedom. This means that from the computational economy point of view, the developed semi‐energy FSM is superior to the full energy FSM. Copyright © 2006 John Wiley & Sons, Ltd.
Free vibration of generally supported rectangular Kirchhoff plates: State‐space‐based differential quadrature method
Authors: Lü C. F. , Zhang Z. C. , Chen W. Q.
Published: November 2006

The title problem is investigated using the differential quadrature method based on the state‐space formalism. The plates, with mixed boundary conditions, may cross over one‐way internal rigid line supports that impose zero transverse displacement constraints. Differential quadrature procedure is applied in the direction of line supports, while exact solution is sought in the transfer domain perpendicular to the line supports using the state space method. To avoid numerical instability in the transfer matrix method, joint coupling matrices are introduced, mainly according to the continuity conditions at line joints. Natural frequencies of rectangular Kirchhoff plates with general boundary conditions are calculated and compared with the results from other methods. Effects of location of internal line supports and the mixed boundary conditions on the frequency parameters are discussed. Copyright © 2006 John Wiley & Sons, Ltd.
A meshless method for axi‐symmetric poroelastic simulations: numerical study
Authors: Ferronato Massimiliano , Mazzia Annamaria , Pini Giorgio , Gambolati Giuseppe
Published: November 2006

A meshless model, based on the meshless local Petrov–Galerkin (MLPG) approach, is developed and implemented for the solution of axi‐symmetric poroelastic problems. The solution accuracy and the code performance are investigated on a realistic application concerning the prediction of land subsidence above a deep compacting reservoir. The analysis addresses several numerical issues, including the parametric selection of the optimal size of the local sub‐domains for the weak form and the nodal supports, the appropriate integration rule, and the linear system solver. The results show that MLPG can be more accurate than the standard finite element (FE) method on coarse discretizations, with its superiority decreasing as the nodal resolution increases. This is due to both a slower convergence rate and a progressively higher computational cost compared to FE. These drawbacks can be partially mitigated by improving the efficiency of the numerical integration and the system solver with the aid of projection techniques based on Krylov subspace methods. The outcome of the present analysis supports the development of coupled methods where a limited number of MLPG nodes are used to locally improve a FE solution. Copyright © 2006 John Wiley & Sons, Ltd.
Synthesis and Rh(I)‐catalyzed polymerization of 1,3‐diphenylyne–calix[4]arene compounds: Novel conjugated, calixarene‐based polymers
Authors: Costa Alexandra I. , Prata José V.
Published: November 2006

The synthesis of two 1,3‐bis(4‐ethynylbenzyloxy)calix[4]arenes, 5,11,17,23‐tetrakis(1,1‐dimethylethyl)‐25,27‐bis(4‐ethynylbenzyloxy)‐26,28‐dihydroxycalix[4]arene (1) and 25,27‐bis(4‐ethynylbenzyloxy)‐26,28‐dihydroxycalix[4]arene (2), was accomplished through Sonogashira coupling of appropriate calixarene derivatives. Methods for the polymerization of these bifunctional building blocks with Rh(I) as a catalyst, leading ultimately to conjugated polymers having calix[4]arene units incorporated into the main chain, were explored. Calixarenes 1 and 2 were efficiently polymerized with rhodium‐based initiators and afforded the conjugated polymers poly{5,11,17,23‐tetrakis(1,1‐dimethylethyl)‐25,27‐bis(4‐ethynylbenzyloxy)‐26,28‐dihydroxycalix[4]arene} (poly 1) and poly{25,27‐bis(4‐ethynylbenzyloxy)‐26,28‐dihydroxycalix[4]arene}. Depending on the conditions, high conversions and good yields were obtained. The effects of adding cocatalysts (NHEt2 and/or PPh3) were studied in connection with the number‐average molecular weight and the molecular weight distribution of the resultant polymer (poly 1) and tentatively correlated with the formation of low‐molecular‐weight materials. A catalytic system containing triphenylphosphine as the sole additive ([Rh(nbd)Cl]2; [Rh]/[PPh3] = 0.5) proved to be the best for the polymerization of p‐tert‐butylcalixarene compound 1. Linear polymers having high number‐average molecular weights (up to 1.1 × 105 g mol−1) with low polydispersities were produced under these conditions. For debutylated homologue 2, its polymerization was best carried out in the absence of any added cocatalyst. A cyclopolymerization route, comprising the intramolecular ring closing of the calix[4]arene pendant ethynyl groups followed by an intermolecular propagation step, is advanced to explain the results. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 7054–7070, 2006
A study of the In Vivo activity of the leaf extract of Alchornea cordifolia against multiply antibiotic resistant S. aureus isolate in mice
Authors: Igbeneghu O. A. , Iwalewa E. O. , Lamikanra A.
Published: November 2006

The effect of a 50% aqueous ethanol extract of Alchornea cordifolia (Schum and Thonn) Muell. Arg. leaf was investigated in mice which had been infected intraperitoneally with 5.0 × 109 cfu of Staphylococcus aureus. Dose‐dependent antibacterial activity was demonstrated and the rate of survival of infected mice was improved significantly by doses between 25 and 200 mg/kg of injected extract when compared with untreated infected controls. The intraperitoneal median lethal dose of the extract was found to be 800 mg/kg. Copyright © 2006 John Wiley & Sons, Ltd.
Additional antiprotozoal flavonol glycosides of the aerial parts of Helianthemum glomeratum
Authors: Calzada Fernando , Alanís Alma Delia
Published: November 2006

Bioassay‐guided fractionation of the methanol extract of aerial parts from Helianthemum glomeratum afforded five antiprotozoal flavonol glycosides: tiliroside, kaempferol‐3‐O‐(3″,6″di‐O‐E‐p‐coumaroyl)‐βd‐glucopyranoside, astragalin, quercitrin and isoquercitrin. The in vitro antiprotozoal assay showed that tiliroside was the most potent antiamoebic and antigiardial compound with IC50 values of 17.5 µg/mL for Entamoeba histolytica and 17.4 µg/mL for G. lamblia. Isoquercitrin showed selectivity against E. histolytica (IC50 14.7 µg/mL) and quercitrin toward G. lamblia (IC50 24.3 µg/mL). All isolated compounds were less active than metronidazole and emetine, two antiprotozoal drugs used as positive controls. Copyright © 2006 John Wiley & Sons, Ltd.
A liquid chromatography/tandem mass spectrometric approach for the determination of gangliosides GD3 and GM3 in bovine milk and infant formulae
Authors: Sørensen Lambert K.
Published: November 2006

A liquid chromatographic/tandem mass spectrometric method using pneumatically assisted electrospray ionisation (LC/ESI‐MS/MS) was developed for the determination of gangliosides GD3 and GM3 in milk and infant formulae. The gangliosides were extracted in a chloroform/methanol/water environment and cleaned up by solid‐phase extraction (SPE) on an end‐capped C8 sorbent. The gangliosides were detected in negative ion mode after separation on a reversed‐phase (RP) C5 analytical column. From the different ganglioside molecular species, product ions at m/z 290 corresponding to an N‐acetylneuraminic acid fragment were produced in the collision cell and used in selected reaction monitoring. A standard addition technique was applied for quantification. The relative repeatability standard deviations were less than 5% for GD3 (level 10 mg/L) and 14% for GM3 (level 0.1–0.2 mg/L). Copyright © 2006 John Wiley & Sons, Ltd.
Site‐specific carbon isotope analysis of aromatic carboxylic acids by elemental analysis/pyrolysis/isotope ratio mass spectrometry
Authors: Oba Yasuhiro , Naraoka Hiroshi
Published: November 2006

Site‐specific carbon isotope composition of organic compounds can provide useful information on their origin and history in natural environments. Site‐specific isotope analyses of small amounts of organic compounds (sub‐nanomolar level), such as short‐chain carboxylic acids and amino acid analogues, have been performed using gas chromatography/pyrolysis/isotope ratio mass spectrometry (GC/pyrolysis/IRMS). These analyses were previously limited to volatile compounds. In this study, site‐specific carbon isotope analysis has been developed for non‐volatile aromatic carboxylic acids at sub‐micromolar level by decarboxylation using a continuous flow elemental analysis (EA)/pyrolysis/IRMS technique. Benzoic acid, 2‐naphthylacetic acid and 1‐pyrenecarboxylic acid were pyrolyzed at 500–1000°C by EA/pyrolysis/IRMS to produce CO2 for δ13C measurement of the carboxyl group. These three aromatic acids were most efficiently pyrolyzed at 750°C. Conventional sealed‐tube pyrolysis was also conducted for comparison. The δ13C values of CO2 generated by the continuous flow technique were within 1.0‰ of those performed by the conventional technique, indicating that the new continuous flow technique can accurately analyze the carbon isotopic composition of the carboxyl group in aromatic carboxylic acids. The new continuous flow technique is simple, rapid and uses small sample sizes, so this technique will be useful for characterizing the isotopic signature of carboxyl groups in organic compounds. Copyright © 2006 John Wiley & Sons, Ltd.
Partially saponified triglyceride ethoxylates
Authors: Cox Michael F. , Weerassoriya Upali
Published: November 2006

Various triglycerides (coconut oil, palm kernel oil, tallow) were ethoxylated with a proprietary catalyst (calcium/aluminum alkoxide complex partially neutralized in an alcohol ethoxylate base) to obtain triglyceride ethoxylates. Triglyceride ethoxylates were then partially saponified with sodium hydroxide to form mixtures of mono‐, di‐, and triglyceride ethoxylates, fatty acid soap, and glycerol ethoxylate. These mixtures were characterized in terms of physical properties, surface activity, and mildness. Partially saponified triglyceride ethoxylates were found to be unexpectedly mild and capable of imparting mildness to other surfactants.
Effect of fiber substrates on appearance and removal of aged oily soils
Authors: Chi Yong‐Seung , Obendorf S. Kay
Published: November 2006

Aging of oily soils produces difficult‐to‐remove yellow stains on fabrics. This study examines the effect of different textile substrates on yellowing and removal of aged oily soils. Model oily, squalene and artificial sebum, were aged at 40°C on cotton, nylon, and polyester fabrics for 8 wk. Radiotracer and spectrophotometric analyses were used to quantify volatilization and color change of soiled fabrics upon aging as well as soil and color removal after laundering. Differences in volatility of oils from three substrates were insignificant, although cotton and nylon fabrics produced significantly more yellowness than polyester fabrics. Aging of oily soil enhanced detergency from all three fabrics. The largest increase in removal upon aging was found with cotton. Difference in removal from the three substrates became very small after aging. The effect of substrate was pronounced on yellowing due to aging with cotton and nylon having higher yellowness indices. Cotton visually appeared to be cleaner than indicated by the actual amount of residual oil present after washing, whereas nylon had less residual oil present even though it visually appeared more yellow than cotton. For polyester, the amount of residual oil correlated well with appearance after washing. We conclude that discoloration mechanisms differ among cotton, polyester, and nylon substrates. For polyester, discoloration is solely discoloration of oily soil that is physically bound in the fibrous structure, whereas for cotton, discoloration is a result of discoloration of oil as well as additional yellowing caused by retention of chromophores chemically bound to the cotton substrate. In the case of nylon, yellowing of nylon itself is an additional factor contributing to yellowness even though, most of the oil is removed upon washing. These results illustrate the importance of the method of detergency evaluation. Measuring color change in yellowness or reflectance is not the same as oil removal based on a quantitative measurement of soil mass. Thus, it may be necessary to measure both color and quantity of residual soil.
Preparation and properties of new lactose‐based surfactants
Authors: Wilk Kazimiera A. , Syper Ludwik , Burczyk Bogdan , Maliszewska Irena , Jon Marek , Domagalska Beata W.
Published: November 2006

A new group of nonionic saccharide‐based surfactants, N‐alkanoyl‐N‐methyllactitolamines (alkanoyl: decanoyl, lauroyl, myristoyl, palmitoyl, stearoyl), were synthesized and characterized. Surface properties such as critical micelle concentration, standard free energy of adsorption, standard free energy of micellization, surface tension reduction efficiency, effectiveness of surface tension reduction, surface excess concentration, and surface area demand per molecule as well as foaming properties (i.e., foam volume and foam stability), contact angle, antiraicrobial activity, and biodegradability were determined. The selected performance properties were evaluated in relation to commercially available alkyl polyglucosides (Glukopon 600 EC(HH)‐a Henkel product), and oligooxyethylenated decyl (C10E4) and dodecyl (E12E5) alcohols. The foaming‐stabilizing effect and contact angle suggest that the lactose‐derived surfactants that were studied share some common properties with alkyl polyglucosides that are different from those with an oligooxyethylene grouping. All tested N‐alkanoyl‐N‐methyllactitolamines were practically nontoxic to bacteria and yeasts. These compounds are readily biodegradable in the Closed Bottle test inoculated with activated sludge. N‐Alkanoyl‐N‐methyllactitolamines with lower chain lengths (C10–C14) biodegraded at a slightly faster rate. Biological properties showed that this class of compounds fulfills all requirements needed for environmental acceptance.
Microbial survival and odor in laundry
Authors: Munk Signe , Johansen Charlotte , Stahnke Louise H. , Adler‐Nissen Jens
Published: November 2006

The survival and distribution of microflora during laundering at 30 or 40°C in commercial U.S. and European Union (E.U.) detergents were determined in laboratory wash experiments. Four test strains—Staphylococcus epidermidis, S. aureus, Escherichia coli, and Pseudomonas aeruginosa—were evaluated on cotton textile. A significant survival and transfer between textiles were found for all four test strains washed in E.U. and U.S. color detergents (without bleach), whereas no survival was observed in bleach‐containing detergents. Gram‐negative strains generally survived in greater numbers than Gram‐positive strains. A greater survival was observed in U.S. detergents at U.S. conditions (30°C, 12 min) than in E.U. detergents at E.U. conditions (40°C, 30 min). The adhesion of odorants to cotton and polyester textiles during washing and drying was studied using six previously identified odorants in laundry [ethylbutanoate, (Z)‐4‐heptenal, (E)‐2‐nonenal, 3‐methylbutanoic acid, 2‐methoxyphenol (guaiacol) and 4‐methyloctanoic acid]. All odorants were effectively removed from cotton during wash, whereas the odorants were more strongly associated with polyester fibers. During wash, hydrophobic odorants [(Z)‐4‐heptenal, (E)‐2‐nonenal, and guaiacol] adhered more strongly to polyester than the acids. The odor formed by surviving skin microflora attached to textiles soiled with human sebum and sweat after laundering at 30°C was studied by sensory evaluation and aroma extract dilution analysis. Intensive odor was formed in both cotton and polyester textiles during prolonged drying. Generally, the odor formation in cotton swatches and the bacterial count of the wash liquor from cotton swatches were greater than the odor formation and bacterial count from polyester swatches. Odorants with animal notes (branched fatty acids) dominated the odor profile after prolonged drying. Polyester swatches possessed a more complex odor profile than cotton; in particular, aldehydes were more dominating in polyester than in cotton. A high‐impact and malodorous component, 3‐methylindole, was formed during prolonged drying in cotton. The study demonstrates that microbial odor formation is a dominating factor determining the odor impression of laundered cotton and polyester textiles dried under slow drying conditions. The initial soiling with aromatic components has an additional impact on the odor profile of polyester textiles after wash, due to strong adherence of odorants during the wash cycle.
Sugar‐based cationic surfactants: Synthesis and aggregation of methyl 2‐acylamido‐6‐trimethylammonio‐2,6‐dideoxy‐d‐glucopyranoside chlorides
Authors: Bazito Reinaldo C. , El Seoud Omar A.
Published: November 2006

The synthesis of the sugar‐based cationic surfactants methyl 2‐acylamido‐6‐trimethylammonio‐2,6‐dideoxy‐d‐glucopyranoside chlorides is reported here. Aggregation of these surfactants (predominantly α anomers) in water was studied at 25°C by conductivity measurements. Increasing the chain length of the amido group R decreased the critical micelle concentration (CMC) and the degree of counter‐ion dissociation. The dependence of the Gibbs' free energy of micellization and CMC on the length of R is similar to that observed for other ionic surfactants. The free energy of transfer of the head group, i.e., cationic amino sugar moiety, from water to the micelle is more negative than that of other ionic surfactants, including sodium methyl 2‐acylamido‐2‐deoxy‐6‐O‐sulfo‐d‐glucopyranosides, probably due to a combination of a micellar “medium” effect and intermolecular H‐bonding in the micellar pseudophase.
Another new family of “extended” glucidoamphiphiles. Synthesis and surfactant properties for different sugar head groups and spacer arm lengths
Authors: Scorzza C. , Godé P. , Goethals G. , Martin P. , Miñana‐Pérez M. , Salager J. L. , Usubillaga A. , Villa P.
Published: November 2006

Following a new four‐step route, we prepared a family of “extended” glucidoamphiphiles from D‐glucose, D‐galactose, and xylitol in which the n‐dodecyl chain is attached to the glucidic moiety by the linkage Z=O‐Et‐O‐Et‐O‐(α‐PP‐O‐)n′ where‐O‐(α‐PP‐O‐)n is a poly‐(α‐propyloxy) commercial oligomeric mixture (with average length n=6, 10, and 14). This amphiphilic behavior study showed that (i) the glucose derivative exhibits water solubility and hydrophilic‐lipophilic balance values that are close to those found for the glucose compound with Z=‐O‐(α‐PP‐O‐)n (without the Et‐O‐Et group), (ii) all these compounds are more strongly hydrophilic than the corresponding glucidic derivatives with Z=O, (iii) the increase of the poly‐(α‐propyloxy) chain length from ñ=6 to ñ=14 tends to reduce the hydrophilicity slightly.
Synthesis of new extended surfactants containing a carboxylate or sulfate polar group
Authors: Fernández Alvaro , Scorzza Cesar , Usubillaga Alfredo , Salager Jean‐Louis
Published: November 2006

New extended anionic surfactants with a carboxylate or sulfate polar head were synthesized from polypropoxylated alcohols, and their structures were confirmed by 1H and 13C nuclear magnetic resonance analysis. The extended surfactant critical micelle concentration was found to decrease with the length of the polypropylene glycol spacer. Surfactants containing a diethylene glycol link to the head group exhibited a higher critical micelle concentration than did their nondiethoxylated homologs.
The role of enzymes in modern detergency
Authors: Olsen Hans Sejr , Falholt Per
Published: November 2006

Enzymes have effectively assisted the development and improvement of modern household and industrial detergents. The major classes of detergent enzymes—proteases, lipases, amylases, and cellulases—each provide specific benefits for application in laundry and automatic dishwashing. Historically, proteases were first to be used extensively in laundry detergents. In addition to raising the level of cleaning, they have also provided environmental benefits by reducing energy consumption through shorter washing times, lower washing temperatures, and reduced water consumption. Today proteases are joined by lipases and amylases in improving detergent efficacy especially for household laundering at lower temperatures and, in industrial cleaning operations, at lower pH levels. Cellulases contribute to overall fabric care by rejuvenating or maintaining the new appearance of washed garments. Enzymes are produced by fermentation technologies that utilize renewable resources.