bluuebunny/crossref_metadata_2025 huggingface dataset:
Lipid hydroperoxides determination in milk‐based infant formulae by gas chromatography
Authors: Lagarda María Jesús , Mañez José Gabriel , Manglano Pilar , Farré Rosaura
Published: June 2003

A simple gas chromatograph using a flame ionization detector and a polar capillary column method is proposed for determining hydroperoxides in the lipid fraction of milkbased infant formulas. Tricosanoic acid is used as internal standard. The method includes the following steps: a) the extraction of fat with chloroform/methanol (2:1, v/v), b) the reduction of hydroperoxide acids to hydroxide acids with hydrogen gas and palladium as a catalyst, c) the transmethylation to obtain the methyl esters with acetyl chloride and methanol/ hexane (4:1, v/v), and d) an acetylation with acetic anhydride/ pyridine (4:1, v/v) to obtain an acetoxy derivate of the hydroxide present. Two chromatography runs, before and after the acetylation step, are carried out. The decrease in the retention time observed after the acetylation process is the criterion used to detect the hydroperoxide. A gas chromatography‐mass spectrometry analysis is applied to confirm the conversion of hydroperoxide acids to the acetylated forms and to identify the specific hydroperoxide structures.

The estimated precision expressed as relative standard deviation (12.1%) and the accuracy, estimated by recovery assays (105 ± 28.3%) confirm the analytical quality of the method. In the milk‐based infant formula analyzed after storage of 11 months at 22 °C, the total hydroxide found corresponded to C18. The gas chromatography‐mass spectra obtained after the acetylation step confirmed the presence of methyl 9‐ and 13‐acetoxyoctadecanoate/s, respectively, derived from the corresponding peroxides.
Electrocatalytic Properties and Sensor Applications of Fullerenes and Carbon Nanotubes
Authors: Sherigara Bailure S. , Kutner Wlodzimierz , D'Souza Francis
Published: June 2003

The electrochemical behavior of fullerene and fullerene derivatives are reviewed with special reference to their catalytic and sensor applications. Recent work on carbon nanotubes, used as catalyst supports in heterogeneous catalysis and sensor development is also presented. An overview of recent progress in the area of fullerene electrochemistry is included. Several cases of electrocatalytic dehalogenation of alkyl halides, assisted by the electrode charge transfer to fullerenes, are discussed. Research work on the electrocatalysis of biomolecules, such as hemin, cytochrome c, DNA, coenzymes, glucose, ascorbic acid, dopamine, etc. have also been considered. Based on the studies of the interaction of fullerenes, fullerene derivatives, and carbon nanotubes with other molecules and biomolecules in particular, the possibilities for the preparation of electrochemical sensors and their application in electroanalytical chemistry are highlighted.
Cobalt Phthalocyanine‐Based Molecular Materials for the Electrocatalysis and Electroanalysis of 2‐Mercaptoethanol, 2‐Mercaptoethanesulfonic Acid, Reduced Glutathione and L‐Cysteine
Authors: Griveau Sophie , Gulppi Miguel , Pavez Jorge , Zagal José H. , Bedioui Fethi
Published: June 2003

We have investigated the electrocatalytic activity of cobalt tetra‐aminophthalocyanine (CoTAPc) for the one‐electron oxidation of thiols of various sizes, namely 2‐mercaptoethanol, 2‐mercaptoethanesulfonic acid, reduced glutathione and L‐cysteine, using adsorbed monomeric CoTAPc and electropolymerized poly‐CoTAPc films of different thickness on a vitreous carbon electrode. Our results show that the electrocatalytic activity of poly‐CoTAPc films towards the oxidation of the thiols increases slightly with the thickness of the film, but remains similar to that of the adsorbed monomeric CoTAPc. The higher stability of the electropolymerized poly‐CoTAPc films makes them attractive for applications in the activation and/or the detection of thiols. We have assessed this approach by designing ultra‐micro‐carbon‐fiber electrodes, coated with poly‐CoTAPc, and combining their use with different electrochemical techniques (cyclic voltammetry, differential pulse voltammetry and differential normal pulse amperometry) for the electroanalysis of the examined thiols.
Development of an Amperometric Sensor Highly Selective For Dopamine and Analogous Compounds Determination Using Bis(2,2′‐Bipyridil) Copper(II) Chloride Complex
Authors: Del Pilar Taboada Sotomayor Maria , Atsushi Tanaka Auro , Tatsuo Kubota Lauro
Published: June 2003

The use of [Cu(bipy)2]Cl2⋅6H2O as a biomimetic catalyst in the construction of an amperometric sensor for dopamine determination is reported. The sensor was prepared modifying a glassy carbon electrode with a Nafion membrane doped with [Cu(bipy)2]Cl2⋅6H2O complex. The sensor presented a higher response in 0.25 mol  L−1 phosphate buffer solution (pH 7.0), with an applied potential of −50 mV (vs. SCE). In the optimized operational conditions, a linear response range between 35 and 240 μmol  L−1, with a sensitivity of 2.02±0.07 nA l μmoL−1 cm−2 and detection limit of 8.0 μmol  L−1 were typically observed for the sensor. The response time presented for this sensor was 0.5 s, presenting the same response for at least 40 successive measurements, with good repeatability (3.0%) expressed as relative standard deviation for n=6. The difference of the response between four sensor preparations was 4%. A detailed investigation about the sensor response for other sixteen phenolic compounds and interfering species were carried out. The sensor was applied in the determination of dopamine in pharmaceutical preparation with success.
Adapting Mini‐Mental State Examination for dementia screening among illiterate or minimally educated elderly Chinese
Authors: Xu Gelin , Meyer John Stirling , Huang Yuangui , Du Fang , Chowdhury Munir , Quach Minh
Published: June 2003

Background

Illiteracy is prevalent among current elderly Chinese. There are few brief cognitive tests in Chinese designed to screen those possibly demented for more detailed evaluation in a clinical setting.

Objectives

The present study adapted the Mini‐Mental State Examination (MMSE) for screening dementia among illiterate or less educated elderly Chinese.

Methods

Literacy‐dependent items of the MMSE were modified or substituted by equivalent items that are not literacy‐dependment. Some items were modified to provide socio‐cultural compatibility. After developing it, the Chinese adapted MMSE (CAMSE) was administered to 370 elderly outpatients from Xijing hospitals located in Xi'an, China, 93 of whom were found to be demented and 277 non‐demented. Sensitivities and specificities for detecting dementia were evaluated by adjusting for different CAMSE cut‐off points. The optimal cut‐off points of 22 for literates and 20 for illiterates yielded a sensitivity of 83.87% and a specificity of 84.48%. Corresponding positive predictive value (PPV) was 0.65, and negative predictive value (NPV) was 0.94. The impact of literacy on CAMSE and individual test items was also evaluated. Illiterate subjects got a higher CAMSE total score than literate subjects (p < 0.05). Only one out of 12 test items, serial sevens, was negatively influenced by illiteracy (p < 0.01). After an interval of 4–6 weeks, 32 randomly selected subjects were retested with CAMSE. The test–retest reliability for total scores was 0.75 (p < 0.01).

Conclusions

Results suggest that in the socio‐cultural context for Chinese, irrespective of their literacy skills, CAMSE proved feasible for use in clinical settings for dementia screening. Copyright © 2003 John Wiley & Sons, Ltd.
Estimation of sons' intergenerational earnings mobility in the presence of censoring
Authors: Minicozzi Alexandra L.
Published: June 2003

Based on intergenerational data from the Panel Study of Income Dynamics, I provide estimates of income mobility across generations for men. Special attention is paid to issues of censoring caused by a son's unemployment. Employing non‐parametric bounds estimates, I illustrate that previous income mobility estimates rely heavily on (unjustified) assumptions of exogenous selection. Assuming a son's potential income is instead a function of his reason for unemployment and work history, I re‐estimate mobility. Allowing for sampling variability, the range of feasible slopes consistent with these modified bounds restrictions is 0.27 to 0.55. Copyright © 2002 John Wiley & Sons, Ltd.
Identification and estimation of a class of household production models
Authors: Kerkhofs Marcel , Kooreman Peter
Published: June 2003

We consider a class of household production models characterized by a dichotomy property. In these models the amount of time spent on household production does not depend on the household utility function, conditional on household members having a paid job. We analyse the (non‐parametric) identifiability of the production function and the so‐called jointness function (a function describing which part of household production time is counted as pure leisure). It is shown that the models are identified in the two‐adult case, but not in the single‐adult case. We present an empirical application to Swedish time‐allocation data. The estimates satisfy regularity conditions that were violated in previous studies and pass various specification tests. For this data set we find that male and female home production time are q‐substitutes. Copyright © 2003 John Wiley & Sons, Ltd.
Mathematical modeling of gas‐phase biofilter performance
Authors: Jorio Hasnaa , Payre Guy , Heitz Michèle
Published: June 2003

In the present paper, a new mathematical model describing the physical, chemical and biological phenomena involved in the process of contaminant removal in biofilters is developed. In addition to the contaminant, the key components of the present theoretical model are carbon dioxide and oxygen. The model predicts the concentration profile of the key components in the gas phase, the biofilm and the sorption liquid retained in the solid particles composing the filter bed at both steady and transient regimes. The model equations were solved numerically and comparison between theory and experiment showed that the model results for styrene and carbon dioxide concentration profiles were in very good agreement with experimental data for the biofiltration of styrene vapors at steady state. The analysis of oxygen concentration profile in the biofilm predicted by the theoretical model revealed that oxygen limitation does not occur under the operating styrene biodegradation rate in the biofilter. Copyright © 2003 Society of Chemical Industry
Gas phase esterification of acetic acid with ethanol over MoO3 supported on AlPO4 and the effect of modification with phosphomolybdic acid and Ce4+ ions
Authors: Said Abd El‐Aziz A
Published: June 2003

A series of AIPO4–MoO3 (APM) systems with various molybdena loadings (5–50) mol %, same modified with phosphomolybdic acid (PMA) and cerium ions, were prepared by an impregnation method and calcined at 400 °C, except for the samples modified with PMA which were calcined at 350 °C for 4 h. The catalysts were characterized by TG/DTG, XRD, IR spectroscopy, N2 adsorption and electrical conductivity measurements. The surface acidity and basicity of the catalysts were determined by adsorption of pyridine and the dehydration–dehydrogenation of isopropyl alcohol. The catalytic esterification of acetic acid with ethanol was carried out in a convention fixed bed reactor. The results clearly revealed that the catalyst with a composition of 10 mol % MoO3 (APM10) was the most active and selective catalyst for the production of ethyl acetate. Moreover, the yield of ethyl acetate increases on addition of PMA into APM10 while it decreases on the addition of Ce4+ ions. These results were correlated with structure, semiconductivity and the acid–base properties of the prepared catalysts. Copyright © 2003 Society of Chemical Industry
Optimization of extraction of bulk enzymes from spent mushroom compost
Authors: Singh Avneesh D , Abdullah Noorlidah , Vikineswary S
Published: June 2003

The profiling of ligninase, hemicellulase and cellulase of Pleurotus sajor‐caju after inoculation of spawn in bags containing sawdust was done at monthly intervals for a period of 6 months. Xylanase (EC 3.2.1.8) was produced throughout the 6 months studied with the productivity range from 5.60 to 7.51 U g−1. Cellulase (EC 3.2.1.4) and β‐glucosidase (EC 3.2.1.21) productivities were highest at 4 months, producing 3.31 U g−1 and 121.13 U g−1 respectively. Laccase (EC 1.10.3.2) productivity was highest at 2 months with a value of 7.59 U g−1. Lignin peroxidase (EC 1.11.1.14) productivity was highest at 5 months with a value of 206.20 U g−1. Total soluble proteins were highest at 4 months with a value of 0.139 mg cm−3. The profiling of lignin peroxidase in 5‐month‐old spent mushroom compost was monitored over a period of 10 months. It was observed that lignin peroxidase was produced throughout the period but productivity was variable. The average lignin peroxidase productivity ranged from 30 to 110 U g−1. The activities of the enzymes extracted in tap water at pH 8.4 were comparable to that extracted in 50 mmol sodium citrate buffer at pH 4.8 and distilled water at pH 5.2 at 4 °C using an incubator shaker at 200 rpm for 18 h. The optimum extraction time was 1 h using an incubator shaker at 4 °C. When an incubator shaker was used, there was no significant difference in the recovery of xylanase, cellulase and laccase at different pH values at 4 °C and 28 °C. No significant difference was observed in the recovery of β‐glucosidase using an incubator shaker at different pH values at 4 °C although the enzyme recovery was slightly higher at pH 8.12, with a value of 29.27 U g−1. The optimum extraction of β‐glucosidase was at pH 4 at room temperature using an incubator shaker. For the lignin peroxidase enzyme, the optimum pH for extraction was 6 at 4 °C and pH 7 at room temperature using an incubator shaker at 200 rpm for 1 h. Homogenization for 8 min at 8000 rpm using tap water at pH 4 had an advantage over the use of the incubator shaker for the extraction as high titers of enzymes were recovered. Copyright © 2003 Society of Chemical Industry
Effect of ring promoter on ionic mass transfer in a fluidized bed
Authors: Venkateswarlu P , Rao VSVSN , Srinivasa Krishna N , Subba Rao D
Published: June 2003

Mass transfer data were obtained at the wall of a batch fluidized bed in the presence of a ring promoter used for the reduction of ferricyanide ion. The ring promoter was a copper rod on which rings of uniform size were fixed at equal distances. In these studies, the cross‐sectional diameter of the ring, the spacing between the rings, the particle size and the void fraction were varied and the limiting current data were measured. It was observed that the mass transfer coefficients were augmented with increased particle diameter, decreased spacing between the rings, and increased cross‐sectional diameter of the ring. Copyright © 2003 Society of Chemical Industry
Pedotransfer functions for the pool size of slowly mineralizable organic N in sandy arable soils
Authors: Heumann Sabine , Böttcher Jürgen , Springob Günther
Published: June 2003

The major aim of this study was to evaluate how the pool size of slowly mineralizable, ‘old’ soil organic N can be derived from more easily accessible soil and site information via pedotransfer functions (PTF). Besides modeling, this pool size might be of great importance for the identification of soils with high mineralization potential in drinking‐water catchments. From long‐term laboratory incubations (ca. 200 days) at 35 °C, the pool sizes of easily mineralizable organic N (Nfast), mainly in fresh residues, and slowly mineralizable, ‘old’ soil organic N (Nslow) as well as their first‐order rate coefficients were obtained. 90 sandy arable soils from NW Germany served to derive PTFs for Nslow that were evaluated using another 20 soils from the same region. Information on former land‐use and soil type was obtained from topographical, historical, and soil maps (partly from 1780). Pool size Nslow very strongly depends on soil type and former land‐use. Mean pool sizes of Nslow were much lower in old arable lowland (105 mg N kg–1) than upland soils (175 mg N kg–1) possibly due to lower clay contents. Within lowlands, mean pool sizes in former grassland soils (245 mg N kg–1) were 2 to 3 times larger than in old arable soils due to accumulation of mineralizable N. In contrast, mean pool sizes of Nslow were lowest in recently cleared, former heath‐ and woodland (31 mg N kg–1) as a result of the input of hardly decomposable organic matter. Neither N nor C in the light fraction (density < 1.8 g cm–3) was adequate to derive pool size Nslow in the studied soils (r2 < 0.03). Instead, Nslow can be accurately (r2 = 0.55 – 0.83) derived from one or two basic soil characteristics (e.g. organic C, total N, C : N, mineral fraction < 20 μm), provided that sites were grouped by former land‐use. Field mineralization from Nslow during winter (independent data set) can be predicted as well on the basis of Nslow‐values calculated from PTFs that were derived after grouping the soils by former land‐use (r2 = 0.51***). In contrast, using the PTF without soil grouping strongly reduced the reliability (r2 = 0.16).
Differences in manganese efficiency of wheat (Triticum aestivum L.) and raya (Brassica juncea L.) as related to root‐shoot relations and manganese influx
Authors: Sadana Upkar Singh , Samal Debasmita , Claassen Norbert
Published: June 2003

Manganese efficiency is a term used to describe the ability of plants to obtain higher relative yields at low Mn supply compared to other species. To evaluate Mn efficiency of wheat (Triticum aestivum L.) and raya (Brassica juncea L.), a greenhouse pot experiment was conducted using Mn deficient Typic Ustochrept loamy sand soil, treated with 0, 50, and 100 mg Mn (kg soil)–1. In the no‐Mn treatment, wheat had produced only 30 % of its maximum dry matter yield (DMY) with a shoot concentration of 10.8 mg Mn (kg DM)–1 after 51 days of growth, while raya had produced 65 % of its maximum DMY with 13.0 mg Mn (kg DM)–1. Taking relative shoot yield as a measure of Mn efficiency, raya was more efficient than wheat. Both crops produced the maximum DMY with 50 mg Mn (kg soil)–1. Even though raya had a lower root length : DMY ratio and a higher shoot growth rate, it acquired higher Mn concentrations in the shoot than wheat under similar soil conditions, because of a 2.5 times higher Mn influx. Model calculations were used to calculate the difference of Mn solution concentration (ΔCL) between the bulk soil (CLi) and the root surface (CL0) that is needed to drive the flux by diffusion equal to the measured influx. The results showed that ΔCL was smaller than CLi, which indicates that chemical mobilization of Mn was not needed to explain the observed Mn uptake even for raya. According to these calculations, the higher Mn influx of raya was caused by more efficient uptake kinetics, allowing for a 4.5 times higher Mn influx at the same Mn concentration at the root surface.
New technique for chest opening in mice: U‐sternotomy
Authors: Schrepfer Sonja , Deuse Tobias , Reichenspurner Hermann
Published: June 2003

In cardiac xenotransplantation, transfections with recombinant adeno‐associated viruses could be a promising way of modulating the cardiomyocyte genome. Proteins like TRAIL, hDAF, Il‐10, Il‐4, and β‐galactosidase may be expressed on cardiomyocyte surfaces in order to prevent cellular rejection processes. However, after intracoronary perfusion with transfecting viruses, it takes up to 4 weeks before expression of the transgene can be detected. Mouse models have been established to create reliable transfection protocols. Currently, the major problem involves performing the intraaortic injection in mice without causing a lethal pneumothorax. Here we describe a new technique for chest opening to safely reach the mouse ascending aorta without opening the pleural space. This U‐sternotomy reduces the risk of animal death and therefore the amount of quite expensive virus solutions needed. © 2003 Wiley‐Liss, Inc. MICROSURGERY 23:274–275 2003
Alternative approach using the combined technique of nerve crossover and cross‐nerve grafting for reanimation of facial palsy
Authors: Yamamoto Yuhei , Sasaki Satoru , Sekido Mitsuru , Yokoyama Toichiro , Tsutsumida Arata , Furukawa Hiroshi , Sawamura Yutaka , Sugihara Tsuneki
Published: June 2003

An alternative approach, using a combination of nerve crossover and cross‐nerve grafting technique in a single‐stage procedure, was developed for the reconstruction of reversible facial palsy. This combined technique provides some benefits such as early facial reanimation resulting from the single‐stage procedure, less morbidity and sufficient innervation with an application of the end‐to‐side anastomosis method, and efficient neural regeneration due to coaptation of the intratemporal facial nerve. Facial nerve rehabilitation, based on double innervation by hypoglossal and contralateral healthy facial nerves, takes advantage of reliable and physiological facial reanimation. © 2003 Wiley‐Liss, Inc. MICROSURGERY 23:251–256 2003
Use of mixed lymphocyte reaction to identify subimmunosuppressive FK‐506 levels in mice
Authors: Ellis Ramsay A. , Brenner Michael J. , Mackinnon Susan E. , Myckatyn Terence M. , Hunter Daniel A.
Published: June 2003

The immunosuppressive agent FK‐506 has a well‐described neuroregenerative effect that is mediated by a mechanism independent of calcineurin inhibition. FK‐506 levels that fall below the threshold for immunosuppression could therefore potentially enhance nerve regeneration while minimizing toxicity. The purpose of this study was to characterize the dose‐dependent effects of FK506 on T‐cell proliferation, and establish a subimmunosuppressive dosing regimen for FK‐506 in mice. Forty BALB/cJ mice were randomized to four groups corresponding to 0, 0.25, 0.5, or 1.0 mg/kg/day doses of FK‐506. Ten days postoperatively, animals were sacrificed, and mixed lymphocyte reaction assays were performed to quantify the immune response to nerve allografts. Mice receiving 0.25 and 0.5 mg/kg/day of FK‐506 exhibited a robust T‐cell proliferation response, with stimulation indices approaching those of untreated animals. Mice treated with 1.0 mg/kg/day of FK‐506 demonstrated significantly decreased T‐cell proliferation. These results establish 0.5 mg/kg/day as an upper limit for subimmunosuppressive FK‐506 administration. © 2003 Wiley‐Liss, Inc. MICROSURGERY 23:276–282 2003
One‐stage reconstruction of facial paralysis associated with severe skin scar deformity, using combined flexor carpi radialis muscle and radial forearm free flap
Authors: Antohi Nicolae , Stan Vitalie , Nitescu Cristian
Published: June 2003

The authors present a case of free microsurgical transfer of combined flexor carpi radialis muscle and radial fasciocutaneous forearm flap in reconstruction of facial paralysis associated with severe ipsilateral skin scar deformity after removal of a giant cavernous hemangioma 22 years previously. The flexor carpi radialis muscle was used to reanimate the paralyzed face, and its fasciocutaneous radial forearm part restored overlying hemifacial skin, with good functional and rather pleasing aesthetic results. The follow‐up period was 5 years. © 2003 Wiley‐Liss, Inc. MICROSURGERY 23:194–197 2003
Anisotropy in optical transmittance and molecular chain orientation of silver‐ dispersed uniaxially drawn polyimide films
Authors: Matsuda Sho‐ichi , Ando Shinji
Published: June 2003

The anisotropy in optical transmittance in the visible and near‐infrared region observed for uniaxially drawn and silver‐dispersed polyimide (PI) films was investigated. The films were prepared in a one‐step operation that consists of thermal curing and simultaneous uniaxial drawing of poly(amic acid) (PAA) films dissolving 5.7 ∼ 20 mol% of silver nitrate. The PAA was converted to PI by heating, and the PI chains were orientated along the drawing direction during curing. Silver nanoparticles were precipitated in the films when they were cured in air and under nitrogen. In particular, silver nanoparticles aggregated along drawing direction and spheroidal nanoparticles (size of longer axis: 10–25 nm, aspect ratio: ca. 1.5) were observed in the films cured in air, and distinct anisotropy in optical transmittance was observed. The maximum optical anisotropy was obtained with a specific holding time at the final curing temperature (320 °C). In addition, the anisotropy can be controlled by polymer chain orientation when films are cured with the optimal holding time. In optimized preparing conditions, anisotropies in transmittance larger than 500 : 1 were obtained at the wavelengths between 700 and 900 nm, and its optical properties were retained after annealing at 150 °C for 1 hr. The PI films thus obtained can be used as thermally stable thin‐film polarizers. Copyright © 2003 John Wiley & Sons, Ltd.
Redox reaction of PEO modified cytochrome c adsorbed on the electrode in ion conductive PEO matrix analyzed with non‐contact optical waveguide spectroscopy
Authors: Fujita Kyoko , Ohno Hiroyuki
Published: June 2003

Optical waveguide spectroscopy was used under non‐contact conditions to analyze the visible absorption spectrum of poly(ethylene oxide) (M
w = 150) modified cytochrome c (PEO150‐cyt.c) adsorbed on an indium tin oxide (ITO) glass electrode. The redox reactions of the adsorbed PEO150‐cyt.c were dynamically measured in situ in PEO oligomers (M
w = 200). It was confirmed that PEO modification of cyt.c is effective in maintaining the redox activity of the cyt.c after adsorption on the ITO glass electrode. The PEO150‐cyt.c adsorbed on the electrode re‐dissolved gradually in PEO oligomer. Against this, PEO1000‐cyt.c having longer PEO chains (M
w = 1000) was found to be adsorbed stably on the electrode. Copyright © 2003 John Wiley & Sons, Ltd.
Acrylate‐based pressure sensitive adhesive in fabrication of transdermal therapeutic system
Authors: Tipre Dnyanesh N. , Vavia Pradeep R.
Published: June 2003

An acrylate‐based pressure sensitive adhesive (PSA) was synthesized to incorporate in a design of a drug‐in‐adhesive (DIA) type transdermal therapeutic system (TTS) for nitrendipine and nicorandil in treatment of hypertension and angina pectoris, respectively. Solutions of 2‐ethylhexyl acrylate (EHA; 85% w/w), methyl methacrylate (MMA; 10% w/w), acrylic acid (AA; 3% w/w) and vinyl acetate (VA; 2% w/w) in either ethyl acetate, acetone or methanol were polymerized under free radical conditions to synthesize the PSA. The effects of solvent, reaction time, initiator concentration and reaction temperature on polymerization were studied. The resultant copolymers were characterized by 1H‐NMR, IR, differential scanning calorimetry (DSC) and gel permeation chromatography (GPC) and the intrinsic viscosities, refractive index, peel strength, moisture uptake and skin irritation potential were determined. The PSA was used to develop DIA type patches for delivery of nitrendipine and nicorandil. The TTS were evaluated for thickness, weight, peel strength, moisture uptake, in vitro release and in vitro skin permeation through guinea‐pig skin. The copolymer found to effectively control the rate of drug release and the corresponding TTSs could be successfully employed in transdermal delivery of nitrendipine and nicorandil. Copyright © 2003 John Wiley & Sons, Ltd.
Synthesis and characterization of hyperbranched aromatic polyesters used for polymeric graded‐index materials
Authors: Kou Huiguang , Shi Wenfang , Lu Yonghua , Ming Hai
Published: June 2003

A series of hyperbranched aromatic polyesters, with different numbers of terminal naphthyl groups per molecule, were synthesized from 5‐hydroxyisophthalic acid as an AB2 type monomer and ethylenediaminetetraacetic acid as an ‘initiator core’ molecule via an ‘one‐step’ approach, to be modified with β‐naphthol. These polyesters had polydispersities in the range 1.78–2.13, indicated by gel permeation chromatography, and degrees of branching between 0.45 and 0.60 by 1H NMR using model compounds. Characterization indicated intense absorption bands in the near‐UV spectral region and one fluorescence centre with emission at 365 nm. The refractive index increased with the number of naphthyl groups up to a value of 1.6205. The diffraction efficiency was about 8.7% for diffraction grating of cured films. Copyright © 2003 Society of Chemical Industry
Mechanism of solvent entrapment within the network scaffolding in organogels: thermodynamic and kinetic investigations
Authors: Markovic Nov , Ginic‐Markovic Milena , Dutta Naba K
Published: June 2003

A detailed investigation on the thermodynamic behaviour of the physical and chemical organogels, using differential scanning calorimetry (DSC) and modulated thermogravimetric analysis (MTGA), is presented. Aluminium soap of fatty acid was used as the physical gelator and in situ crosslinking of siloxane copolymer was used for chemical gelation. The effects of the type and concentration of the gelators and the corresponding mesh‐size distribution of the gel network scaffolding on the trapped‐solvent crystallization, melting and evaporation mechanism, and kinetics are examined. It appears that the kinetics of crystallization of the trapped‐solvent are significantly affected by the quality of the gel network scaffolding and can be treated successfully by the Avrami equation of crystallization. From the melting behaviour of the entrapped‐solvent crystallites, quantitative information about the number of solvent molecules bound per molecule of the gelator has been extracted. The effect of gelation network structure on the kinetics of evaporation of the solvent from the gel network scaffolding has been evaluated. DSC appears to be the reliable technique to evaluate the population distribution of solvent molecules trapped in the gel network scaffolding. Copyright © 2003 Society of Chemical Industry
Novel approach to highly porous superabsorbent hydrogels: synergistic effect of porogens on porosity and swelling rate
Authors: Kabiri K , Omidian H , Zohuriaan‐Mehr MJ
Published: June 2003

A novel practical strategy for preparing highly porous superabsorbent hydrogels (HPSHs) was invented. HPSHs were quantitatively prepared through an optimized rapid convenient solution polymerization of partially neutralized acrylic acid in the presence of a crosslinking agent under normal atmospheric conditions. Acetone and sodium bicarbonate were used as porosity generators (porogens) during the polymerization process to create highly porous structures. Time and sequence of addition of the porogens, as well as the gelation time of the polymerization, were recognized to affect the efficiency of the porogens. Sodium bicarbonate produced the more porous hydrogels with a higher rate of swelling. In comparison with a hydrogel prepared under porogen‐free conditions (control), acetone and sodium bicarbonate enhanced the swelling rate as high as 43–55% and 111–131% of the control, respectively. When both the porogens were used consecutively in the process, a remarkable synergistic effect was observed in the swelling rate of the products. Nearly all the two‐porogen processes resulted in foamy products from the polymerization system. With the single‐porogen systems, however, the foam formation stage was observed only in a part of the total process time. The apparent volume of the as‐synthesized foamy products prepared from the two‐porogen system was more than that of the single‐porogen systems by up to fourfolds. Morphological studies using scanning electron microscopy (SEM) showed that the two‐porogen systems created highly porous structures. The density of all the HPSHs synthesized was about 1.5 g cm−3 and no distinct differences were observed in their equilibrium swelling. These superabsorbent hydrogels exhibited a very high rate of swelling, so that their swelling time was measured to be less than one minute. Copyright © 2003 Society of Chemical Industry
Toughness and morphology of radiation‐crosslinked natural rubber modified polystyrene
Authors: Aiamsen P , Paiphansiri U , Sangribsub S , Polpanich D , Tangboriboonrat P
Published: June 2003

γ‐Radiation vulcanized natural rubber (RVNR)/phase transfer/suspension polymerization technique was used to prepare high‐impact polystyrene (HIPS) in bead form. The high notched Izod impact resistance of HIPS based on RVNR was observed and compared with that of unmodified PS. The impact resistance of HIPS based on RVNR was further enhanced by addition of 10% of polystyrene‐block‐polyisoprene‐block‐polystyrene copolymer. A mesh structure of all crosslinked rubber particles containing polystyrene and long crazes in HIPS were observed under electron microscopy. Copyright © 2003 Society of Chemical Industry
Copolymerization of bromophenylmaleimide with ethyl or butyl methacrylate
Authors: Naguib HF , Saad GR , Elsabeé MZ
Published: June 2003

N‐p‐Bromophenylmaleimide (BrPMI) does not polymerize in solution by conventional free radical mechanism. However, it readily polymerized in bulk when mixed with a free radical initiator and heated in a microwave oven for 7–8 min. Copolymerization of ethyl methacrylate or butyl methacrylate with BrPMI was conducted in dioxane. The copolymers were characterized by IR and 1H NMR spectroscopy and gel permeation chromatography. The monomer reactivity ratios were calculated by a non‐linear least‐square analysis. Thermal analysis indicated a great improvement in thermal stability of the copolymers compared with the methacrylate homopolymers. BrPMI was also polymerized in bulk in the DSC pan, which allowed the calculation of the activation energy of its polymerization. Copyright © 2003 Society of Chemical Industry
Analysis of complex autoantibody repertoires by surface‐enhanced laser desorption/ionization‐time of flight mass spectrometry
Authors: Grus Franz H. , Joachim S. C. , Pfeiffer Norbert
Published: June 2003

Normal sera contain a large number of naturally occurring autoantibodies which can mask important disease‐associated ones. Western blotting has evolved as the most important tool to demonstrate autoantibodies in autoimmune diseases, because of its ability to simultaneous screening for a wide spectrum of different antigens. In previous studies we have shown the diagnostic potential of the analysis of autoantibodies in autoimmune diseases by means of multivariate statistics and artificial neural networks. However, the Western blotting procedure remains very time‐consuming and is also limited in sensitivity. Therefore, we used an on‐chip approach for the analysis of autoantibodies. This ProteinChip system uses ProteinChip arrays and SELDI‐TOF MS (surface‐enhanced laser desorption/ionization‐time of flight mass spectrometry) technology for capturing, detection, and analysis of proteins without labelling or without the need of chemical modification. The microscale design of the arrays allows the analysis of very small quantities of proteins. In the present study, we used arrays with biologically activated surfaces that permit antibody capture studies. Protein‐A‐Chips were incubated with sera of patients (n = 12). After washing, the chips were incubated with a complex solution of autoantigens and subsequently washed again. If the Protein‐A bound autoantibodies recognized their antigens, these proteins could be separated by their molecular masses and were to be detected by mass spectrometry. Previous studies using monoclonal antibodies have demonstrated that the detection limit is in the attomole level. Furthermore, all sera were analyzed by conventional Western blotting for direct comparison. In the present study, we have shown complex on‐chip antibody‐antigen reactions. At higher molecular weights (> 30 kDa) the detection sensitivity of this on‐chip method was comparable to conventional Western blotting. At lower molecular mass, the Western blot technique is easily exceeded by the on‐chip method. Considering that this on‐chip procedure is quite easy to use, is much less time‐consuming than Western blotting, and is much more sensitive at least in the low molecular weight range, the SELDI‐TOF technology is a very promising approach for the screening of autoantibodies in autoimmune diseases. Due to its versatility, this on‐chip technology could allow the large‐scale screening for complex autoantibody distributions for diagnostic purposes and early detection of autoimmune diseases might be possible.
Proteomic analysis of changes in the extracellular matrix of Arabidopsis cell suspension cultures induced by fungal elicitors
Authors: Ndimba Bongani K. , Chivasa Stephen , Hamilton John M. , Simon William J. , Slabas Antoni R.
Published: June 2003

A proteomic approach has been applied to investigate changes in the extracellular matrix of Arabidopsis thaliana cell suspension cultures following treatments with two fungal pathogen elicitors, chitosan and extracts of Fusarium moniliforme. The oxidative burst and induction of glutathione S‐transferase were used as markers for induction of the pathogen defence response. Changes in the cell wall and culture filtrate proteome were profiled. Proteins whose abundance changed reproducibly were analysed via matrix assisted laser desorption ionisation‐time of flight (MALDI‐TOF) mass spectrometry (MS). An increase in the level of two classical cell wall proteins (a putative endochitinase and a polygalacturonase inhibiting protein) and two novel proteins (a putative receptor‐like protein kinase and a probable apospory‐associated protein) were seen at 24 hours following elicitation. The level of an unknown protein and a hypothetical protein, which has some homology to serine carboxypeptidases, were decreased at 24 hours post‐elicitation. In the culture filtrate extracts, we identified two pathogen elicitor responsive proteins, a xyloglucan endo‐1,4‐β‐D glucanases (XEG) and a peroxidase. Using a combination of two‐dimensional polyacrylamide gel electrophoresis, immunoblotting with a phosphotyrosine‐specific antibody, and MALDI‐TOF MS we discovered that spots that represent putative lectin receptor‐like kinase, a putative endochitinase and a XEG possess phosphorylated tyrosine residues. The identification of phosphorylated bona fide cell wall proteins and a putative extracellular receptor‐like kinase with no transmembrane domain implicate the existence of an extracellular phosphorylation network which could be involved in intercellular communication.
Membrane proteome of Acinetobacter radioresistens S13 during aromatic exposure
Authors: Pessione Enrica , Giuffrida Maria Gabriella , Prunotto Laura , Barello Cristina , Mazzoli Roberto , Fortunato Donatella , Conti Amedeo , Giunta Carlo
Published: June 2003

Study of the bacterial membrane proteome, though in its early stages, is a field of growing interest in the search for information about nutrient transport and processing. We tested different strategies and chemical compounds to extract proteins from the membranes (inner and outer) of Acinetobacter radioresistens S13, a Gram‐negative bacterium selected for its ability to degrade aromatics. A. radioresistens S13 was monitored under different growth substrate conditions, using acetate, benzoate or phenol as sole carbon source. Two‐dimensional gel electrophoresis map analysis of membrane extracts from benzoate‐ and phenol‐grown cells reveals differences versus controls (acetate‐grown cultures). Primarily, a different pattern of spots was observed and, in particular, some proteins were only expressed in the presence of aromatic substrate. Among these, we detected a Na+/H+ antiporter, whose function is likely to be regulation of intracellular pH, and an ABC type sugar transport system, probably involved in capsular polysaccharide translocation. We also identified other proteins, detectable in acetate‐grown but over‐expressed in aromatic‐grown cells. These include: (1) an outer membrane protein ascribable to an OmpA‐like protein, recently described in the literature as “alasan”, a bioemulsifying agent involved in solubilizing and enhancing bioavailability of hydrocarbons; (2) a trimeric porin of the PhoE family also belonging to the outer membrane and involved in facilitating the transport of anions (especially phosphate); and (3) two glycosyl transferases probably involved in capsules and/or lipopolysaccharide biosynthesis. Study of the bacterial membrane proteome helps to elucidate the role of the membrane as modulable site enabling communication between internal and external environments.
The sizes of molecules—revisited
Authors: Marcus Yizhak
Published: June 2003

The size of molecules, be it their volume, surface area or linear extent, is an important quantity in many fields of chemistry. Molecules are often tacitly or explicitly treated as if they were spheres, so that a diameter can be assigned to them. However, the molecules of many kinds of substances are rather cylindrical, being rod‐ or disk‐shaped, so that two linear dimensions are needed for their description. The collision diameters obtainable from experimental data on gases and vapors or diameters obtained from the molar volume or the application of an expression for the interaction potential in liquids, e.g. the Lennard–Jones potential, are explored as ways to yield information on molecular sizes. The ratio of the van der Waals volume and surface area is related to a simple expression derived solely from the composition of the molecules for various types of molecular shapes. These approaches were applied to a database of 350 mainly liquid (but also some gaseous and solid) organic (and a few inorganic) substances. Copyright © 2003 John Wiley & Sons, Ltd.
Transport properties of organic vapors in nanocomposites of isotactic polypropylene
Authors: Gorrasi Giuliana , Tammaro Loredana , Tortora Mariarosaria , Vittoria Vittoria , Kaempfer Dirk , Reichert Peter , Mülhaupt Rolf
Published: June 2003

Isotactic polypropylene nanocomposites were obtained by the melt blending of polypropylene‐graft‐maleic anhydride and organophilic layered silicate (OLS) consisting of synthetic fluorohectorite modified by cation exchange with protonated octadecylamine. The composition of the inorganic clay was varied between 2.5 and 10 wt %, and films of the composites were obtained via hot‐press molding. X‐ray analysis showed that nanocomposites in which silicate layers were either delaminated or ordered as in an intercalated structure were obtained. The elastic modulus of the samples was higher than that of the pure polymer over a wide temperature range and increased with increasing inorganic content. The transport properties, sorption and diffusion, were measured for two organic vapors, dichloromethane and n‐pentane. For both vapors, the sorption was not very different from that of the pure polymer, whereas the zero‐concentration diffusion parameter strongly decreased with increasing OLS content. Therefore, the permeability, that is, the product of sorption and diffusion, decreased for both vapors as a result of the decreased value of the diffusion parameter. The decrease was higher for the less interacting n‐pentane. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 1798–1805, 2003
The association between social support, intrusive thoughts, avoidance, and adjustment following an experimental cancer treatment
Authors: Devine Danielle , Parker Patricia A. , Fouladi Rachel T. , Cohen Lorenzo
Published: June 2003

A social‐cognitive processing model was used to examine the association of social support with intrusive thoughts and avoidance in predicting adjustment in 53 patients receiving an experimental vaccine for the treatment of either metastatic melanoma (n=24) or metastatic renal cell cancer (n=29). Social support, intrusive thoughts/avoidance, psychological distress and quality of life were assessed on the day of the first treatment, on the day of the final treatment, and 1 month after the end of treatment during a routine follow‐up visit. Social support at the beginning of treatment was negatively associated with psychological distress and positively associated with mental health quality of life (QOL) 1 month after treatment, and these associations were mediated by intrusive thoughts/avoidance at the end of treatment. There was also an interaction between social support and intrusive thoughts/avoidance at the beginning of treatment in predicting both psychological distress and mental health QOL 1 month after treatment. Specifically, for patients with lower levels of support, greater intrusive thoughts/avoidance was associated with greater psychological distress and poorer mental health QOL 1 month after treatment. However, there was no association between intrusive thoughts/avoidance and adjustment in patients with high levels of social support. These results suggest that social support buffers the negative association between intrusive thoughts/avoidance and psychological adjustment. Overall, the results are consistent with a social‐cognitive processing model of post‐trauma reactions among cancer patients. Our results highlight the need to assess patients' perceived support and to further develop and assess the benefits of interventions to increase patients' supportive networks and to facilitate cognitive processing of the cancer experience. Copyright © 2003 John Wiley & Sons, Ltd.
The fertility‐ and menopause‐related information needs of younger women with a diagnosis of breast cancer: A qualitative study
Authors: Thewes Belinda , Meiser Bettina , Rickard Judy , Friedlander Michael
Published: June 2003

The use of chemotherapy and endocrine therapies in the treatment of pre‐menopausal women carries with it reproductive and gynaecological implications which younger women may find both unpleasant and discordant with plans for childbearing. This study aims to investigate the fertility‐ and menopause‐related information needs of younger women with a diagnosis of early breast cancer. A retrospective qualitative methodology was chosen. Twenty‐four women aged between 26 and 45 years at diagnosis participated in focus group interviews and telephone interviews. Many women thought that the information they had received in the past about fertility and menopausal symptoms was either insufficient or unavailable. Some women felt that, while information on fertility and menopause issues had not been paramount at the time of diagnosis, it became increasingly important after diagnosis. Participants spoke about the need to revisit or review fertility‐ and menopause‐related information with their doctors during the course of treatment. Many women believed that information about fertility should be given prior to or during treatment decision‐making, and that information related to the management of menopausal symptoms should be delivered during or after treatment when menopausal symptoms begin. Consultation with a fertility and/or menopause specialist‐rated as the most preferred mode of receiving fertility‐ and menopause‐related information. Clinical implications are drawn from the results of this study to assist clinicians and researchers to improve their communication with younger patients about the fertility‐ and menopause‐related side effects of breast cancer treatment. Copyright © 2003 John Wiley & Sons, Ltd.