bluuebunny/crossref_metadata_2025 huggingface dataset:
Parison formation and inflation behavior of polyamide‐6 during extrusion blow molding
Authors: Wagner Alan H. , Kalyon Dilhan M.
Published: April 2004

Parison formation and inflation behavior of three polyamide 6 resins during extrusion blow molding were investigated using cinematography, a transparent mold, a pinch‐off mold and a modified blow pin, which allowed the pressure inside the parison to be determined during inflation. The glass fiber filled polyamide exhibited negligible extrudate swell and significant drawdown, whereas polyolefin modified polyamide exhibited appreciable extrudate swell and relatively small drawdown effects. The inflation behavior of the polyolefin modified polyamide was similar to the behavior of conventional blow molding grade polyolefins, whereas the unmodified and glass filled polyamides exhibited different inflation characteristics. Their inflation behavior at different internal pressures was characterized by decreasing and increasing Hencky strain rates with inflation time at high and low internal blow pressures, respectively. The characterized parison formation and inflation behavior of the polyamides emphasize the importance of rigorous blow moldability experiments and the difficulties associated with linking various rheological material functions to the blow moldability of modified polyamides.
Radiation processing of polymer insulators: A method for improving their properties and performance
Authors: Ivanov V. S. , Migunova I. I. , Kalinina N. A. , Aleksandrov G. N.
Published: April 2004

Polymer insulators for electric apparatus and high‐voltage overhead lines are promising for replacing porcelain and glass insulators. The possibility of this application is shown by radiation‐chemical technology for the manufacture of rodshaped polymer insulators. An ethylene and vinyl acetate copolymer (EVA) was used as the basis for polymer insulators. The composition also contains aluminium hydroxide as a filler and N,N′‐m‐phenylene dimaleimide as a sensitizer. The investigation of γ‐radiation‐induced crosslinking of this composition made it possible to establish the following optimum conditions of radiation processing of insulators: the absorbed dose of up to 200 kGy at a dose rate of 10 kGy/h in air. By forming a three‐dimensional network in the polymer bulk by radiation, the service properties of the insulators are improved: Shape and heat stability is >200°C and the stability to tracking and erosion >200 h. Differential scanning calorimetry (DSC) and a method of stress relaxation were used in evaluation. In the Saint Petersburg region (Russia), several types of high‐voltage (10–110 kV) polymer insulators are manufactured with the application of such radiation‐chemical technology.
Numerical simulation of blow molding—prediction of parison diameter and thickness distributions in the parison formation process
Authors: Tanoue Shuichi , Kajiwara Toshihisa , Funatsu Kazumori , Terada Kousuke , Yamabe Masashi
Published: April 2004

In our previous study, we calculated the time course of parison length in the parison formation stage, but it could predict only the parison area swell. The next target in our study is to calculate the parison diameter and thickness swell. Annular extrudate swell simulation is necessary for the understanding of various kinds of swelling ratios in blow molding. We have examined three kinds of swells (outer diameter, thickness, and area swells) obtained from simulation results of annular extrudate swell, using the Giesekus model, and have developed a method of predicting parison outer diameter and thickness swell values. The predicted values of parison outer diameters are discussed in comparison with experimental data, and reasonable results are obtained by the proposed method. This prediction method could also be applied to the parison formation process using a parison controller. As a result, it is possible to predict approximately the whole process of parison formation by numerical simulation.
The glass transition temperature of nitrated polystyrene/poly(acrylic acid) blends
Authors: Al‐Najjar Mohammed M. , Hamid S. Halim , Hamad Esam Z.
Published: April 2004

Low‐molecular‐weight polystyrene was nitrated to different levels. The nitrated polystyrene was blended with different molecular weights of poly(acrylic acid), PAA. The glass transition temperatures (Tg) for the mixtures were investigated by differential scanning calorimetry. A single Tg was observed for all blends, indicating single‐phase blends. In general, it was found that the Tg increases with molecular weight of PAA. The Tg values of the blends showed a positive deviation from the linear average Tg as a result of strong hydrogen bonding between the segments of the component polymers. The observed Tg values were not adequately represented by simple predictive equations or by single‐parameter fitting equations. However, two‐parameter fitting equations gave a reasonable representation of the data.
Non‐fickian diffusion with reaction in glassy polymers with swelling induced by the penetrant—effects of consecutive and parallel reactions
Authors: Kuipers Norbert J. M. , Beenackers Antonie A. C. M.
Published: April 2004

A mathematical model is presented for non‐Fickian diffusion of a penetrant A into a granular glassy polymer containing a reactive group B, resulting in the desired product P. Further, both a consecutive reaction between A and P (producing X) and a parallel reaction between A and C (producing Y) are incorporated, with C initially present in the particle. The swelling of the polymer, induced by the penetrant, is described by power‐law kinetics for the velocity of the swelling front. Kinetics are considered to be first order in each of the two reactants. Concentration profiles in the particle and selectivity to desired product are calculated as function of the swelling behavior of the polymer grain. In case of a consecutive reaction the local concentration of P reaches a maximum value independent of the swelling rate. However, the position of the maximal concentration of P moves towards the center of the grain with a rate depending on the kinetics of swelling. For Case II diffusion this velocity equals the velocity of the advancing front between glassy and rubbery polymer. The selectivity of the desired reaction decreases with decreasing swelling rate. A low swelling rate also results in an inhomogeneous product distribution within the granule. A criterion is derived predicting under what conditions the consecutive reaction can be neglected and a pure product is obtained. The analysis further reveals that both a more homogeneous product and a higher selectivity toward a desired product can be obtained by realizing preswelling of the polymer with an inert swelling agent. For Case II diffusion the concentration profiles of the side product of the parallel reaction, Y, are flat in the rubbery part of the polymer. This is caused by the relatively low swelling rate allowing Y to redistribute in the swollen polymer. If additional C is continuously supplied from the gas phase, then the selectivity decreases continuously with increasing conversion of B.
Bubble dissolution in molten polymers and its role in rotational molding
Authors: Kontopoulou M. , Vlachopoulos J.
Published: April 2004

The presence of bubbles is inherent in the rotational molding process and can often cause poor quality in rotomolded parts. In an effort to gain a fundamental understanding of bubble removal in polymer melts, a model that includes diffusion, surface tension, and viscosity effects has been implemented. This work has been complemented with experiments performed in a heated chamber, which enabled the visualization of the bubble formation and removal process. It was concluded that bubble removal is mainly diffusion controlled and is not influenced significantly by melt viscosity when the latter lies within ranges typical for rotational molding resins. Air concentration in the bulk of the polymer melt and initial bubble size were found to be of great importance. The application of pressure after the polymer has melted accelerates the dissolution rate, owing to an increased driving force for diffusion.
Analysis of an LDPE compact autoclave reactor by two‐cell model with backflow
Authors: Lee Jinsuk , Ham Jae Yong , Rhee Hyun‐Ku , Chang Kil Sang , Kim Jae Youn
Published: April 2004

A two‐cell model with backflow and heat exchange is developed to analyze the dynamics of an LDPE compact autoclave reactor. The backflow exists between the two mixing cells and represents the degree of mixing within the reactor. The performance of the reactor and the physical properties of the product polymer such as the number average molecular weight and the polydispersity are investigated under various operating conditions, especially when the initiator feed concentration is varied. Bifurcation diagrams are constructed by taking the initiator feed concentration as the bifuracation parameter and the dynamic feature in the feasible parameter ranges for operation are carefully examined. Indeed, various dynamic characteristics are observed by performing numerical analysis of the nonadiabatic system with the internal cooling device. As the rate of heat transfer increases, various multiplicity patterns and oscillatory behavior such as the limit cycle and the focus are found. The reactor behavior even undergoes period doubling and gradually gives rise to a chaotic behavior in certain ranges of the initiator feed concentration when the coolant temperature becomes low. The existence of chaos is examined by the phase plane plot and Poincaré map. Apparently, the monomer concentration can be substantially increased with proper heat removal and initiator supplement scheme. For this, however, the complex dynamic features must be taken into account in the reactor design.
Processing and properties of high‐temperature creep‐resistant PVC plastisols
Authors: Tai Horng‐Jer
Published: April 2004

The effect of the use of an unsaturated reactive plasticizer trimethylopropane trimethacrylate, TMPTMA, on the structure and the creep behavior of poly(vinyl chloride), PVC, plastisols has been investigated as part of a program to develop a high‐temperature creep‐resistant liner material. The crosslinking reaction was initiated with a peroxide. The effect on the network structure of using a free radical scavenger in the formulation has also been studied. Gel yield and grafted PVC content in the gel increase with increased TMPTMA content in the plastisol. However, the residual unsaturation of TMPTMA decreases with increase of TMPTMA content. Introduction of TMPTMA into the plastisol promotes the creep resistance at high temperatures, and the effectiveness increases when there are PVC molecules grafted onto TMPTMA networks.
Effect of molecular structure on the rotational molding characteristics of ultra‐low‐density ethylene‐α‐olefin copolymers
Authors: Wang W. Q. , Kontopoulou M.
Published: April 2004

The rotational molding characteristics of two ultra‐low‐density ethylene‐α‐olefin copolymers with elastomeric properties (polyolefin plastomers), made by metallocene catalysts, were investigated with the purpose of examining the effect of molecular structure on their processability. Particle coalescence and densification experiments revealed that higher comonomer content resulted in slower rates of coalescence and densification, thus affecting bubble content. Based on detailed material characterization, slower densification was attributed to the presence of broad melting endotherms, higher viscosity immediately after the melting transition, and higher melt elasticity. Investigation of the effect of particulate form revealed that use of powders instead of micropellets resulted in the formation of fewer bubbles on the outer surface, because of the broader particle size distribution, leading to improved appearance, better mechanical properties, and reduced overall processing time. Rotomolded parts displayed excellent impact properties and a high degree of flexibility. Polym. Eng. Sci. 44:496–508, 2004. © 2004 Society of Plastics Engineers.
Microstructural modifications in uniaxially hot‐drawn polycyclohexylene terephthalate films
Authors: Kattan M. , Dargent E. , Grenet J.
Published: April 2004

Semi‐aromatic thermoplastic polycyclohexylene terephthalate (PCT), initially wholly amorphous, was uniaxially drawn to study microstructural modifications as the appearance of the strain‐induced (S.I.) crystalline phase. Polyethylene terephthalate (PET) and poly(ethylene glycol‐co‐cyclohexane‐1,4‐dimethanol terephthalate) (PETG) are considered as reference materials in this work. In polycyclohexylene terephthalate (PCT) the presence of a saturated ring (which is not quite as rigid as the aromatic ring) modifies the characteristics of both thermal and S.I. crystallization. Samples with various draw ratios (drawing of PCT films is performed at T > Tg) were analyzed by Modulated Differential Scanning Calorimetry, wide angle X‐ray scattering, and birefringence measurements. In drawn PCT films, an S.I. crystalline phase appears continuously with the draw ratio and reaches 35%. For this polymer and for the highest draw ratio, the “true” amorphous fraction practically disappears. The material is composed only of the S.I. crystalline phase and the “rigid” amorphous phase. Polym. Eng. Sci. 44:509–517, 2004. © 2004 Society of Plastics Engineers.
Uniaxial tensile behavior and thermoforming characteristics of high barrier EVOH‐based blends of interest in food packaging
Authors: Giménez E. , Lagarón J. M. , Maspoch Ma. L. , Cabedo L. , Saura J. J.
Published: April 2004

The uniaxial tensile characteristics of blends of an ethylene‐vinyl alcohol copolymer (EVOH‐32 mol% ethylene) with an amorphous PA and/or a nylon‐containing ionomer, used as barrier layer in multilayer food packaging structures, was assessed in this paper. The stress‐strain behavior of these materials at elevated temperatures and at different strain rates was examined. The stress‐strain curves obtained were used to understand the influence of temperature and strain rate on the uniaxial deformation process of the materials, these being of general importance during typical processing steps including thermoforming. A male mold for deep‐draw was used to assess the thermoforming (biaxial deformation in nature) behavior of extruded sheets at 100, 120, 140 and 150°C, and the results were broadly found to be in agreement with results from simple uniaxial tensile tests. From the preliminary thermoforming results, it was found that EVOH/aPA extruded blends did not improve the poor formability of EVOH alone. In contrast, significant improvement in thermoformability was achieved by blending EVOH with a compatibilized ionomer. Optimum forming capacity was achieved in a ternary blend by addition of a compatibilized ionomer to an EVOH/aPA blend in the range of 140°C–150°C. The ternary blend showed a lower reduction of thickness in the sidewalls, as well as a higher dimensional uniformity in the thermoformed part. Polym. Eng. Sci. 44:598–608, 2004. © 2004 Society of Plastics Engineers.
Fundraising credentialing
Authors: Chobot Richard B.
Published: April 2004

The author presents a critical analysis of certification, licensure, and certificates and the value of each to fundraising professionals.
Compensation: The intersection of valuation and accountability
Authors: Grossnickle Ted R. , Aldrich Eva E.
Published: April 2004

The issue of what constitutes appropriate compensation for fundraising personnel must be framed within the wider context of accountability within the profession.
Building the fundraising team
Authors: Stephens Charles R.
Published: April 2004

Putting together an effective and successful fundraising team is akin to building the institution in microcosm. This chapter presents five fundamental success factors that come into play when building a team and makes the case for why this is important.
Molecular parameters governing the yield response of epoxy‐based glassy networks
Authors: Lesser Alan J. , Calzia Kevin J.
Published: April 2004

This contribution considers to what extent two molecular parameters, the glass transition temperature and the cohesive energy density, relate to the yield behavior of epoxy‐based glassy thermosets. Eight different formulations consisting of four aliphatic and four aromatic resins with varying molecular weights between crosslinks were investigated over a broad range of test temperatures. Additionally, one aromatic formulation is studied over a range of stress states and test temperatures. The results indicate that both the glass transition and cohesive energy density are governing parameters that relate to the yield response of these systems. A model is proposed to incorporate these parameters and to predict the yield response as a function of strain rate, temperature, and stress state. The functional form of the results also indicate that the activation energy density (i.e., the activation energy divided by the activation volume) may be the material characteristic that relates to yield of these systems rather than each term individually. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2050–2056, 2004
Gas trapping in normal infants and in infants with cystic fibrosis
Authors: Castile Robert G. , Iram Durdana , McCoy Karen S.
Published: April 2004

Two different methods for estimating trapped gas volume have been described in the literature. The purpose of this study was to use both of these methods to estimate and compare trapped gas volumes in normal infants and infants with cystic fibrosis (CF). Thirty normal infants and 29 infants with CF, ages 1 month to 3 years, were studied. Pulmonary function tests, including raised volume forced expiratory flows, plethysmographic functional residual capacity (FRCpleth), and fractional lung volumes, were measured. Then functional residual capacity was measured by nitrogen washout (FRCnitrogen). Following nitrogen washout, lungs were then inflated three times to 30 cm H2O, using 100% oxygen. This process was repeated until no further nitrogen could be washed from the lungs. The volume of trapped gas (tg) was calculated from the total additional amounts of nitrogen expired following lung inflations. The difference between FRCpleth and FRCnitrogen provided a second estimate of trapped gas volume (delta V). Mean tg and delta V values for normal infants were 2.5 ± 3.5 ml and 15.6 ± 30.4 ml, respectively. Mean tg and delta V values for infants with CF were 5.8 ± 7.7 ml and 33.2 ± 43.8 ml, respectively. Both tg and delta V did not differ significantly between normal infants and infants with CF. Measured following raised volume forced expiratory maneuvers, delta V and tg do not distinguish infants with CF from normal infants as well as do other currently available tests of infant lung function. Pediatr Pulmonol. 2004; 37:461–469. © 2004 Wiely‐Liss, Inc.
Facemasks and facial deposition of aerosols
Authors: Sangwan Sanjay , Gurses Burak K. , Smaldone Gerald C.
Published: April 2004

Passage of aerosol around or through a facemask can result in deposition on the face and in the eyes. The present study quantified facial and eye deposition in a model simulating drug delivery to a young child. Aerosol delivery and facial deposition of radiolabeled saline test aerosols were studied in vitro with filters and a gamma camera. A child's face facsimile, attached to a piston pump, was used to simulate the patient receiving aerosol therapy. A filter placed in the oropharynx of the face facsimile measured aerosol delivery (inhaled mass). Seven commercially available facemasks in combination with three jet nebulizers were studied for aerosol delivery to the “patient” as well as for deposition on the face and in the eyes. Inhaled mass varied from 2.24–5.96% of nebulizer charge (drug placed in the nebulizer). Facial deposition varied from 0.44–2.34% of nebulizer charge, with eye deposition at 0.09–1.78%. All facemasks leaked aerosol, with significant facial and eye deposition approaching in magnitude delivery to the lung. Factors affecting facial and eye deposition include the interactive design characteristics of the facemask and nebulizer, as well as the aerodynamic properties of the aerosol. Pediatr Pulmonol. 2004; 37:447–452. © 2004 Wiely‐Liss, Inc.
Disease severity in siblings with cystic fibrosis
Authors: Katz Sherri L. , Strug Lisa J. , Coates Allan L. , Corey Mary
Published: April 2004

Since cross‐infection occurs between cystic fibrosis (CF) siblings, we hypothesized that subsequent siblings may acquire respiratory pathogens at an earlier age and have a more severe course of pulmonary disease. We studied a retrospective cohort of 31 sibling pairs from the CF database at the Hospital for Sick Children. Kaplan‐Meier curves and modified log‐rank tests were used to test sibling differences in age of acquisition of Pseudomonas aeruginosa (PA), Staphylococcus aureus (SA), or any positive culture. Differences in disease severity outcomes were explored. Older siblings were more likely to have both SA and any CF pathogen first isolated from respiratory culture at an older age than younger siblings (P = 0.0050 and P = 0.0008, respectively, by modified log‐rank tests). However, more of the older siblings were positive on first culture at time of diagnosis, introducing an age‐of‐diagnosis bias. Hospitalization rates, courses of oral antibiotics, FEV1 % predicted, and weight and height measurements were not better in the older children. No differences in clinical parameters were found between older and younger siblings. The apparent finding of younger age at first isolation of pathogens from respiratory cultures in younger siblings is likely because many older siblings were already infected with these organisms at time of diagnosis. Pediatr Pulmonol. 2004; 37:407–412. © 2004 Wiely‐Liss, Inc.
Quantitative cytokine gene expression in CF airway
Authors: Muhlebach Marianne S. , Reed William , Noah Terry L.
Published: April 2004

Bronchoalveolar lavage fluid (BALF) in cystic fibrosis (CF) shows increased inflammation, which could be due to abnormal cytokine regulation. Bronchial epithelial cells and migratory inflammatory cells produce these cytokines, but few quantitative in vivo data are available comparing young CF patients with controls. We hypothesized that IL‐8 mRNA abundance was higher in young CF vs. non‐CF disease control patients in lung epithelium and inflammatory cells. Bronchial epithelial cells (BEC) were obtained by brush biopsy, and airway inflammatory cells (BALFC) by bronchoalveolar lavage, in 17 CF and 21 non‐CF patients <5 years old undergoing clinically indicated bronchoscopy. Cellular mRNA expression was quantified by real‐time PCR and normalized to glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH). Abundance of IL‐8/GAPDH in BEC was significantly higher in CF (14.8 ± 3.3) than non‐CF (4.2 ± 0.6) samples, and this difference was also significant when patients were stratified according to infection. In BALFC, the difference in IL‐8 expression did not reach statistical significance: CF (17.1 ± 6.5) vs. non‐CF (6.8 ± 1.9), but BALF cell number/ml was significantly higher in CF. IL‐10 mRNA was very low in all samples, without showing a decrease in CF vs. non‐CF patients. We conclude that early in the disease, IL‐8 mRNA expression in BEC is increased in CF in vivo. Although IL‐8 mRNA in migratory cells was not significantly higher in CF, these cells may still contribute to elevated IL‐8 in airway secretions, secondary to increased cell density in BALF. Pediatr Pulmonol. 2004; 37:393–399. © 2004 Wiely‐Liss, Inc.
Plasma levels of transforming growth factor‐1β and α2‐macroglobulin before and after radical prostatectomy: association to clinicopathological parameters
Authors: Sinnreich O. , Kratzsch J. , Reichenbach A. , Gläser C. , Huse K. , Birkenmeier G.
Published: April 2004

BACKGROUND

To study the levels of transforming growth factor‐1β (TGF‐β1) and of α2‐macroglobulin (α2‐M), a high affinity binding protein of TGF‐β1, in comparison to prostate‐specific antigen (PSA) in prostate cancer (PCa) patients before and up to 12 months after prostatectomy, and to correlate the results with clinicopathological parameters.

METHODS

Eighty‐one patients who underwent radical prostatectomy for PCa were included in this study. Pre‐ and postoperatively, plasma levels of TGF‐β1, α2‐M and PSA were measured in the same samples by ELISA, and were correlated with pathological parameters and clinical outcomes.

RESULTS

The preoperative TGF‐β1 levels were significantly elevated as compared to the controls; they showed a positive correlation with the Gleason score. Patients with initial androgen‐deprivation therapy had lower TGF‐β1 levels than untreated patients. Elevated concentrations of TGF‐β1 levelled off 12 months after prostatectomy approaching values of healthy individuals. Decreased plasma levels of total and transformed α2‐M (proteinase‐complexed form) were observed in PCa. Preoperative levels of TGF‐β1 but not of α2‐M seem to be influenced by the body mass index (BMI).

CONCLUSIONS

Elevated TGF‐β1 and decreased α2‐M were consistently found in patients with PCa, and may be considered as risk factors for tumor development and progression. In comparison to PSA, the TGF‐β1 levels displayed a slow decline after radical prostatectomy; this indicates that TGF‐β1 is mainly produced outside the prostatic tissue. Since TGF‐β1 levels are influenced by the BMI, this indicates that PCa might be sensitive to diet. © 2004 Wiley‐Liss, Inc.
The pathogenicity of Vairimorpha necatrix (Microspora: Microsporidia) against the tomato moth, Lacanobia oleracea (Lepidoptera: Noctuidae) and its potential use for the control of lepidopteran glasshouse pests
Authors: Down Rachel E , Bell Howard A , Kirkbride‐Smith Anne E , Edwards John P
Published: April 2004

A droplet feeding technique was used to feed known amounts of Vairimorpha necatrix (Kramer) spores to larvae of the tomato moth, Lacanobia oleracea (L) in order to assess the susceptibility of this lepidopteran pest to the pathogen. All first‐ to fourth‐instar larvae died as a result of ingesting 1000 or more V necatrix spores. Two forms of death were observed, which were dependent on the dose and the age of the insect when treated. For first‐instar larvae, rapid death (within 6 days of dosing) occurred after ingestion of 2000 spores, whereas lower doses resulted in a proportion of larvae dying from chronic infection (microsporidiosis). For more advanced stages, increasing spore doses were required to give rapid death, such that a dose of 200 000 spores was needed to give 80% mortality within 6 days for third‐instar larvae. Rapid death was not observed in fourth‐ to sixth‐instar larvae. In all cases successful pupation and adult emergence were much reduced compared with non‐infected larvae.

Suspensions of V necatrix were sprayed on to tomato (Lycopersicon esculentum Mill) plants maintained in small glasshouses prior to infestation of the plants with L oleracea larvae. The numbers and biomass of pest larvae retrieved from the plants sprayed with V necatrix were significantly reduced by up to 40% and 70%, respectively, compared with plants sprayed with water (control). Similarly, plants sprayed with V necatrix showed a reduction in damage of up to 45% compared with the control plants. British Crown copyright 2004. Reproduced with the permission of Her Majesty's Stationery Office. Published for SCI by John Wiley & Sons, Ltd.
CoMFA and CoMSIA Studies of nAChRs Ligands: Epibatidine Analogues
Authors: Zhang Huabei , Liu Chunping , Li Hua
Published: April 2004

A 3D‐QSAR about nAChRs agonists−52 epibatidine analogues (including 3 cytisine analogoues) was performed using the CoMFA and CoMSIA. The coefficients were Rcv2=0.546, Rncv2=0.907, no. of components=4 in CoMFA and Rcv2=0.655, Rncv2=0.962, no. of components=6 in CoMSIA of the final model in the unprotonated state. The results obtained were graphically interpreted in terms of field contribution maps. Since, physicochemical determinants of binding, such as the properties of eletrostatic, steric, hydrophobic, and H bond acceptor and donor were interpreted with the epibatidine structure in the training set. The prediction using the final models to the test set was r2=0.675 in CoMFA and r2=0.462 in CoMSIA. And with the results, we had presumes other assistant element as supplement to the traditional elements. These results were used to guide the rational design of new nAChRs ligands.
A Re‐evaluation of the Use of Rink, BAL, and PAL Resins and Linkers
Authors: Yraola Francesc , Ventura Rubén , Vendrell Marc , Colombo Aina , Fernàndez Joan‐Carles , de la Figuera Natalia , Fernández‐Forner Dolors , Royo Miriam , Forns Pilar , Albericio Fernando
Published: April 2004

The preparation of amine and guanidine derivatives of phenylalaninamide and tryptophanamide as well as benzylamines from BAL, Rink‐MBHA, and Rink resins has been performed. Cleavage of the target compound gave significant amounts of byproducts compounds in which the linker moiety was attached to the target unit. This side reaction can be avoided when the solid supports are prepared by anchoring the corresponding linker to an aminomethyl resin.
Formation of new types of inhomogeneous spatial structures in the chemical reaction in imperfect systems
Authors: Krasilnikov Vladimir V. , Savotchenko Serge E.
Published: April 2004

Taking the system imperfection and the inhomogeneity of the diffusion processes into account derives the extension of a simple chemical reaction model proposed by Schlogl. The Fick equation modification makes the breakdown of the ideality of diffusion. It leads to high‐order spatial derivatives of a concentration in an evolution equation. The system imperfection is also taken into account by the excess Gibbs function of a regular solution. It leads to modification of the chemical potential as well as to the dependence of a diffusion coefficient on a reagent concentration. The formation of the spatial inhomogeneous structures being stable during the chemical reaction under definite conditions is due to the breakdown of an ideal system. Certain spatial inhomogeneous structures can exist only in the imperfection system and do not appear in an ideal system. Three new types of spatial inhomogeneous structures appear: periodic, quasi‐periodic, and nonperiodic structures. The functions characterizing concentration contain two terms. Note that in the ideal systems, the quasi‐periodic and nonperiodic structures cannot exist. This means that such a new spatial structure formation is due to the system imperfection. The parameters characterizing the system imperfection represent the coefficients at nonlinear terms and a high‐order spatial derivative in the evolution equation. This permits consideration of a system deviation from the ideal as a significantly nonlinear phenomenon. The conditions of spatial structure stability are determined mainly by parameters that describe the system imperfection. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Detection of phenolic oxidation products in cider apple juice by high‐performance liquid chromatography electrospray ionisation ion trap mass spectrometry
Authors: Bernillon S. , Guyot S. , Renard C. M. G. C.
Published: April 2004

Juice was prepared from cider apples of the cultivar “Kermerrien” under oxidative conditions. After isolation by solid‐phase extraction, the phenolic fraction was subjected to high‐performance liquid chromatography/electrospray ionisation mass spectrometry. SIM scans were performed at m/z values obtained in model solutions. The oxidation products, resulting from coupling between a molecule of caffeoylquinic acid and caffeoylquinic acid, catechin or dimeric flavan‐3‐ol, were detected. Copyright © 2004 John Wiley & Sons, Ltd.
Environmental risk assessment of medicinal products for human use according to European Commission recommendations
Authors: Huschek Gerd , Hansen Peter D. , Maurer Hans H. , Krengel Dietmar , Kayser Anja
Published: April 2004

Presented here, based on new recommendations of the European Commission, is an environmental risk assessment (ERA) of a selected group of pharmaceuticals for Phase I, environmental exposure assessment, and Phase II Tier A, initial environmental fate and effect analysis. This pharmaceutical group is composed of the 111 highest‐selling human drug substances that have annual sales in Germany of more than 5,000 kg. The data required for this ERA came from analyzing: (1) sales annually (in kg or IU) of the 2671 active pharmaceutical drug substances (2001) on the German market in all medicinal products sold by pharmacies (with and without prescriptions) and used in hospitals in 1996–2001; (2) the use pattern of drug substances as categorized according to Anatomical Therapeutic Chemical (ATC) classification indexes ATC3 and ATC7; (3) data for excretion, toxicity, and metabolites of the 111 selected human drug substances; (4) the physicochemical properties of these substances; and (5) the degradability of selected drug substances in sewage treatment plants (STPs) by using a validated and accredited liquid chromatography–electrospray ionization tandem mass spectrometry method. A correction factor for the pharmaceutical therapeutic (PT) activity of metabolites, the PTIndex (excretion rate/100) for drug substances and PT active metabolites was established to refine the predicted environmental concentration (PECSURFACEWATER). A refinement of the PECSURFACEWATER was carried out with the market penetration factor of the human drug substances in Germany. In addition, for effect analysis the predicted no‐effects concentration (PNEC) was calculated using assessment factors. The estimated PEC results were validated with the exposure results of effluents of the STPs. All results on ERA of drug substances have been documented in a Microsoft Access 2000 database. © 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 226–240, 2004.
Oxidation of bisphenol A, 17β‐estradiol, and 17α‐ethynyl estradiol and byproduct estrogenicity
Authors: Alum Absar , Yoon Yeomin , Westerhoff Paul , Abbaszadegan Morteza
Published: April 2004

A human breast cancer cell line (MCF‐7) was used to investigate the cumulative estrogenicity profiles elicited during the oxidation of three estrogenic compounds [bisphenol A (BPA), 17β‐estradiol (E2), and 17α‐ethynyl estradiol (EE2)]. High‐performance liquid chromatography (HPLC) with a method detection limit (MDL) of ∼1 nM was used to measure the initial and final concentrations of test compounds during oxidation. Both chlorination and ozonation removed from 75% to >99% of the test compounds in distilled water. Increasing contact time and chlorination dose improved compound removal. Chlorination byproducts of BPA, E2, and EE2 elicited low levels of estrogenicity over an extended period of time. For equivalent molar oxidant dosages, ozone and chlorine had comparable residual proliferative effect values and >99% loss of the parent compounds. For oxidation studies of estrogenic chemicals, ammonium chloride was found to adequately quench residual chlorine without interfering with cell culture assay. Oxidation of test compounds with chlorine and ozone resulted in a similar estrogenicity trend, with a relative higher level of estrogenicity elicited during the early phases of oxidation, which gradually dissipated over the extended exposure time to a stable point. Oxidation with ozone resulted in the rapid transformation of test compounds, reaching a stabilized estrogenic level in 10 min, whereas for chlorination it took more than 120 min for elicited estrogenicity to stabilize. © 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 257–264, 2004.
Stepwise fatigue crack propagation in poly(vinyl chloride)
Authors: Berna‐Lara T. E. , Hu Y. , Summers J. , Hiltner A. , Baer E.
Published: April 2004

The kinetics and mechanism of fatigue crack growth in poly(vinyl chloride) (PVC) compounds of different molecular weight were studied. The fatigue crack propagation rate of all the PVC compounds followed the Paris law: da/dt = Af ΔK. Fatigue crack propagation rate, as reflected by the pre‐factor Af in the Paris law, was highly dependent on molecular weight of the resin, strain rate, and temperature. A stepwise mechanism of fatigue crack propagation was observed in all the PVC compounds. Steps were formed by discontinuous growth of the crack through a single craze in the shape of a narrow strip. Step length and lifetime were used to characterize fatigue crack propagation. J. Vinyl Addit. Technol. 10:5–10, 2004. © 2004 Society of Plastics Engineers.
New class of ultraviolet light absorbers
Authors: Grossman Richard F.
Published: April 2004

The DNA bases are found to be effective ultraviolet light absorbers in high‐density polyethylene (HDPE) and poly(vinyl chloride) PVC. J. Vinyl Addit. Technol. 10:41–43, 2004. © 2004 Society of Plastics Engineers.
Evaluation of antioxidant performance of a natural product in polyolefins
Authors: Suffield R. M. , Dillman S. H. , Haworth J. E.
Published: April 2004

Mixed tocopherols were evaluated for antioxidant performance in polypropylene and polyethylene in combination with a phosphite secondary antioxidant by utilizing a two‐factor central composite experimental design with oxidation induction time as the response. A commonly used phenolic antioxidant and synthetic vitamin E (α‐tocopherol) were evaluated in comparison. Mixed tocopherols were found to have a greater antioxidant effect than the phenolic control and a similar to slightly greater effect than vitamin E in both polypropylene and polyethylene. No significant effects of the phosphite on oxidation induction times were observed for either of the tocopherol‐based antioxidants. J. Vinyl Addit. Technol. 10:52–56, 2004. © 2004 Society of Plastics Engineers.
The KlSRB10 gene from Kluyveromyces lactis
Authors: Núñez Laura , Fernández‐Otero Cristina , Rodríguez‐Belmonte Esther , Cerdán M. Esperanza
Published: April 2004

We report the cloning and sequencing of a gene from Kluyveromyces lactis with high homology to the SRB10 gene (alias UME5, SSN3, GIG2, NUT7, RYE5) from Saccharomyces cerevisiae and other organisms. The KlSRB10 gene is located in a similar configuration to that found in S. cerevisiae, flanked by NOT4 and a gene with high similarity to YPL041c. The translated protein contains 593 amino acids and the characteristic domains of kinases from the CMGC subgroup. The functional relationship to yeast SRB10 is demonstrated by complementation of mutant phenotypes in a haploid S. cerevisiae strain containing a null allele. Submitted to EMBL data library under Accession No. AJ532841. Copyright © 2004 John Wiley & Sons, Ltd.
Differential regulation by glucose and fructose of a gene encoding a specific fructose/H+ symporter in Saccharomyces sensu stricto yeasts
Authors: de Sousa Helena Rodrigues , Spencer‐Martins Isabel , Gonçalves Paula
Published: April 2004

Saccharomyces cerevisiae transports fructose through a facilitated diffusion system common to other hexoses and mediated by the Hxt proteins. The related species S. pastorianus (carlsbergensis) and S. bayanus produce, in addition, a specific fructose/H+ symporter. We have previously cloned a gene (FSY1) encoding the active fructose symporter from S. pastorianus PYCC 4457. Expression of Fsy1p in a S. cerevisiae mutant (hxt‐null) devoid of the facilitated diffusion system allows growth on fructose but not on glucose. Here we present results concerning the regulation of Fsy1p expression, both in S. pastorianus and S. bayanus, where it occurs naturally, and in suitably engineered S. cerevisiae transformants. To that purpose, we made use of both Northern blot analysis and a Fsy1p–GFP fusion protein. The expression of Fsy1p is strongly regulated by both the carbon source and its concentration in the growth medium. In S. pastorianus, as well as in S. bayanus, very low concentrations of either fructose or glucose induced expression but higher sugar concentrations prevented transcription of the gene. Glucose was considerably more effective than fructose in repressing FSY1 expression. Proper regulation of the gene in S. cerevisiae seems to be exquisitely dependent on sugar transport. Analysis of Fsy1 expression in S. cerevisiae mutants shows that repression is mainly dependent on Mig1p, the final effector of the main glucose repression pathway. Interestingly, Mig1p also seems to mediate repression of FSY1 expression by high maltose concentrations. Copyright © 2004 John Wiley & Sons, Ltd.
Pellet morphometry as a tool to distinguish age and sex in the mule deer
Authors: Sánchez‐Rojas Gerardo , Gallina Sonia , Equihua Miguel
Published: April 2004

By examining the morphometry (i.e., length, width, length‐to‐width ratio, and volume) of pellets in three different categories (adult males, adult females, and yearlings) mule deer (Odocoileus hemionus), we were able to distinguish via discriminant function and fuzzy clustering analyses the age and sex of these animals. To determine a priori the identity of the pellet samples and evaluate the accuracy of our methods, we obtained samples from individuals in captivity. The discriminant function allowed us to correctly assign 100% of adult males, 91.66% of adult females, and 75% of yearlings to an age class, using previous information. The fuzzy clustering method enabled us to correctly distinguish 100% of adult males, 83.3% of adult females, and 75% of yearlings. The methods are based upon different assumptions. An important assumption with the discriminant function method is that the membership of each pellet group must be established a priori. This may be a disadvantage in certain cases, such as when pellet samples are gathered for an indirect population assessment procedure. Despite this drawback, however, both methods appear to be highly accurate. Zoo Biol 23:139–146, 2004. © 2004 Wiley‐Liss, Inc.
Introducing a fourth primate species to an established mixed‐species exhibit of African monkeys
Authors: Wojciechowski Sheila
Published: April 2004

Five red‐capped mangabeys (Cercocebus torquatus) were gradually introduced to an established mixed‐species exhibit containing six black and white colobus, seven mandrills, and six sooty mangabeys. Interspecific interactions were documented throughout the 3‐month introduction period and for an additional 3 months immediately thereafter. In addition, each species' behavior and exhibit use were documented before and after the addition of the fourth species. Minimal interactions were observed between the red‐capped mangabeys and the colobus or mandrills, and neither species was significantly affected by this addition. Many affiliative and aggressive interactions and changes in behavior were documented in the sooty mangabeys. However, this study shows that even closely related allopatric species can coexist in a captive environment, and the animals can benefit from this association. Zoo Biol 23:95–108, 2004. © 2004 Wiley‐Liss, Inc.
Comparison of two introduction methods for African elephants (Loxodonta africana)
Authors: Burks Kyle D. , Mellen Jill D. , Miller Gary W. , Lehnhardt John , Weiss Alexander , Figueredo Aurelio J. , Maple Terry L.
Published: April 2004

Managers must consider an animal's potential for aggression when they decide to change or form a captive social group formation. In this study we compared two introduction methods (termed “sequential” and “nonsequential” introductions) in African elephants to assess their effectiveness in managing aggression and minimizing stress. Both introduction methods included four phases: baseline, visual contact, limited tactile contact, and physical introduction. In the sequential introduction, these steps were followed sequentially, and empirical data were considered during decision‐making. In the nonsequential introduction, these steps were not followed sequentially, and decision‐making was based primarily on intuitive assessments by animal managers. Behavioral data and fecal corticoid concentrations were measured throughout both types of introduction. The behavior categories measured included active aggression, passive aggression, submissive behavior, undesirable/stress‐related behavior, and affiliative behavior. While the role of affiliative behavior was surprising, general behavior patterns were characterized by increases in behavior as animals progressed to the next phase of introduction regardless of introduction type. These increases then attenuated over time during each phase. Overall, less behavior was observed during the sequential introduction, as predicted. The data suggest that the sequential introduction managed aggression more effectively. Similar patterns were predicted for undesirable/stress‐related behavior and fecal corticoid concentration. Undesirable/stress‐related behavior was a poor predictor of observed behavior patterns. Although the patterns differed from those predicted, higher concentrations of fecal corticoids were measured during the nonsequential introduction and correlated significantly only with submissive behavior. While more investigation is warranted, the data indicate that the nonsequential introduction brought about an increased physiological response. Overall, the sequential introduction method appeared to manage aggression and stress better than the nonsequential technique. Every introduction is subject to factors that can influence success, such as staff experience, the design of the facility, and the animals' social histories. It is hoped that the rigorous sequential protocol will be a useful tool in the animal manager's “toolbox” for planning and implementing introductions. Applications of this introduction method are also discussed. Zoo Biol 23:109–126, 2004. © 2004 Wiley‐Liss, Inc.
Prevention of Peritoneal Carcinomatosis from Colon Cancer Cell Seeding Using a Pirarubicin Solution in Rats and Nude Mice
Authors: Favoulet Patrick , Benoit Laurent , Osmak Liliana , Polycarpe Emmanuel , Esquis Philippe , Duvillard Christian , Guiu Boris , Rat Patrick , Favre Jean Pierre , Chauffert Bruno
Published: April 2004

Free malignant cells, which are frequently detected in the washing liquid from the peritoneal cavity before and after resection of human colorectal cancer, are suspected to cause recurrent peritoneal cancer. We carried out an experimental study to compare the prophylactic efficacy of washing the peritoneum with several anticancer drugs and the antiseptic povidone‐iodine against the development of peritoneal carcinomatosis from colonic origin in rats and nude mice. The in vitro anticancer activity of a short, 15‐minute exposure of pirarubicin, doxorubicin, 5‐fluorouracil, cisplatin, mitomycin C, and 1% povidone‐iodine was first evaluated by an MTT assay on DHD/K12/PROb rat and LS174T human colon cancer cells. For the in vivo experiments, BDIX rats were inoculated intraperitoneally (IP) with 1 x 106 DHD/K12/PROb cells followed by peritoneal scarring and a colocolic anastomosis. A 15‐minute peritoneal washing with the anticancer drugs or povidone‐iodine was then performed. Nude mice were IP‐inoculated with 1 × 107 LS174T human cells and treated 2 hours later with IP pirarubicin. Only pirarubicin, mitomycin C, and povidone‐iodine were fully cytotoxic in vitro against DHD/K12/PROb rat colon cancer cells. In contrast to pirarubicin and povidone‐iodine, mitomycin C was not completely active against LS174Tcells. In vivo, pirarubicin cured DHD/K12/PROb‐inoculated rats, even at the site of the peritoneal scarring and intestinal anastomosis. IP pirarubicin prevented the development of peritoneal carcinomatosis and liver metastasis in LS174T‐inoculated mice. IP washing with pirarubicin cured 2‐day‐old, but not 7‐day‐old, peritoneal carcinomatosis in rats. Short exposure to IP pirarubicin is nontoxic and more active than povidone‐iodine and other anticancer drugs in preventing the development of peritoneal carcinomatosis from colonic origin in rats and mice. The prophylactic effect of preoperative peritoneal washing with pirarubicin on the development of recurrent peritoneal cancer should be evaluated in a randomized clinical trial.