bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and characterization of new polyamides derived from 4‐(4′‐aminophenyl)urazole and aliphatic diacid chlorides
Authors: Mallakpour Shadpour , Rafiee Zahra
Published: March 2004

4‐(4′‐Aminophenyl)urazole (AmPU) was prepared from 4‐nitrobenzoic acid in six steps. The reaction of AmPU with acetyl chloride was performed in N,N‐dimethylacetamide solutions at different ratios, and the resulting disubstituted and trisubstituted amide derivatives were obtained in high yields and were used as models for polymerization reactions. Polycondensation reactions of AmPU with succinyl chloride, suberoyl chloride, and sebacoyl chloride were performed with conventional solution polymerization techniques in the presence of different catalysts, such as pyridine, triethylamine, and dibutyltin dilaurate, and led to the formation of novel aliphatic polyamides. The resulting novel polyamides had inherent viscosities of 0.11–0.22 dL/g in dimethylformamide or H2SO4 at 25°C. These polyamides were characterized with IR, 1H‐NMR, elemental analysis, and thermogravimetric analysis. Some physical properties and structural characterization of these novel polyamides are reported. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3173–3185, 2004
Surface modification of low‐density polyethylene films by a novel solution base chemical process
Authors: Bandopadhay D. , Tarafdar A. , Panda A.B. , Pramanik P.
Published: March 2004

The surfaces of the film samples of low‐density polyethylene (LDPE) were chemically modified with an aqueous solution of ammonium persulphate solution (0.1 M) and Fe (NO3)3,9H2O (0.2 M) heated to about 80°C for 2.5 h for which polar groups like OH, 〉CO, COOH, etc., were generated on the surface of the LDPE films. The modified films were analyzed by Infrared (IR) spectroscopy, Scanning Electron Microscopy (SEM), and Electron Spectroscopy for Chemical Analysis (ESCA). New surface of LDPE produced by this modification, demonstrated reasonable oxygen incorporation on the surface of polymer films through chemical bonding, which is essential for adhesion processes. For these chemical changes the extent of printability and adhesion. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3046–3051, 2004
Determination of dissociable groups in natural and regenerated cellulose fibers by different titration methods
Authors: Fras Lidija , Laine Janne , Stenius Per , Stana‐Kleinschek Karin , Ribitsch Volker , Doleček Valter
Published: March 2004

Different titration methods were applied with the purpose to determine the dissociation properties of a natural (cotton) and regenerated (viscose, modal and lyocell) cellulose fibers. Potentiometric and conductometric titration were used to determine the content of acidic groups. pK values were determined by potentiometric titration. Polyelectrolyte adsorption was used for surface and total charge determination, and to obtain information about charge location and accessibility of charged groups. It was found that the average content of acidic groups is higher in cotton fibers than in regenerated fibers. The fiber charge of cotton is due to the dissociation of two type of acidic groups, one with pK ≈3.5 and the other with pK ≈5.5. In regenerated fibers there is only one type of acidic groups (pK ≈3.5). The pK value of the stronger acid is typical for carboxyl group in uronic acids. The polyelectrolyte adsorption indicates that most of the carboxyl groups are located in an inner region of all cellulose samples (cotton and regenerated fibers). It is concluded that titration methods are powerful tools for monitoring the content, strength, and distribution of acidic groups, as well as the total charge of natural and regenerated cellulose fibers. The three methods give similar results on all analyzed samples and show good repeatability. The results of investigation make it quite clear that combination of all titrations yields relevant information about content and strength of acidic groups in both natural and regenerated cellulose fibers used in the manufacture of textiles. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3186–3195, 2004
Colorants based on renewable resources and food‐grade colorants for application in thermoplastics
Authors: Van Den Oever M.J.A. , Boeriu C.G. , Blaauw R. , Van Haveren J.
Published: March 2004

A series of colorants based on renewable resources and food‐grade colorants have been evaluated for use in polypropylene (PP) and polyvinylchloride (PVC). It has been found that most of these colorants can be processed in PP at 200°C or even 260°C while maintaining good color intensity and color brightness. The colorants evaluated cover a large part of the color spectrum. In PP, the light stability of alizarin (red), carmine (red), indigo (blue), purpurin (red), quinizarin (red), and the aluminium lakes of quinoline yellow (yellow) and indigo carmine (blue) is close to the requirements for indoor applications. The blue colorants indigo and the aluminium lake of indigo carmine are, in principle, sufficiently light stable in PP for indoor applications. A few colorants showed bleeding from PP. Bonding of migrating colorants to the reactive carrier maleic anhydride grafted polypropylene, however, reduced bleeding of the colorant to a large extent. Also after processing in PVC at 200°C, good color intensity and saturation is maintained. Quinizarin, a structural analog of alizarin and purpurin, shows a light stability performance that is close to commercial lead chromate/molybdate orange based colorants. The best performing natural colorants are sufficiently heat and light stable for applications where moderate properties concerning heat resistance and (UV) light stability are required, such as underground PVC water drainage pipes and indoor PP applications. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2961‐2969, 2004
Modeling PVTX diagrams: Application to various blends based on unsaturated polyester—Influence of thermoplastic additive, fillers, and reinforcements
Authors: Boyard N. , Vayer M. , Sinturel C. , Erre R. , Delaunay D.
Published: March 2004

The model previously proposed to predict the volume change of filled blends was extended to unsaturated polyester/styrene blends without or with thermoplastic additive and to blends with fillers and/or fibers. This model was based on experimental results from Pressure Volume Temperature X (PVTX) setup where temperature, conversion degree, and volume at a controlled pressure were monitored simultaneously. Predictions obtained from the model were compared to experimental results and were in good agreement. This model took into account thermal expansion, polymerization shrinkage, and shrinkage compensation via porosity formation. These phenomena were deconvoluted from the experimental curve and separately quantified. It was shown that shrinkage and its compensation induced a volume variation exhibiting a linear dependence with conversion degree. The influences of low‐profile additive content, pressure, fillers, and fiber presence on shrinkage control were highlighted. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2976–2988, 2004
Study on hot air aging and thermooxidative degradation of peroxide prevulcanized natural rubber latex film
Authors: Zhang Bei‐Long , Chen Mei , Ao Ning‐Jian , Deng Wei‐Yong , Liu Hui‐Lun
Published: March 2004

The air‐aging process at 120°C and the thermooxidative degradation of peroxide prevulcanized natural rubber latex (PPVL) film were studied with FTIR and thermal gravity (TG) and differential thermal gravity (DTG) analysis, respectively. The result of FTIR shows that the OH and COOH absorption of the rubber molecules at IR spectrum 3600–3200 cm−1, the CO absorption at 1708 cm−1, and the COH absorption of alcohol at 1105 and 1060 cm−1 increased continuously with extension of the aging time, but the CH3 absorption of saturated hydrocarbon at 2966 and 2868 cm−1, the CH3 absorption at 1447 and 1378 cm−1, and the CC absorption at 835 cm−1 decreased gradually. The result of TG‐DTG shows that the thermal degradation reaction of PPVL film in air atmosphere is a two‐stage reaction. The reaction order (n) of the first stage of thermooxidation reaction is 1.5; the activation energy of reaction (E) increases linearly with the increment of the heating rate, and the apparent activation energy (E0) is 191.6 kJ mol−1. The temperature at 5% weight loss (T0.05), the temperature at maximum rate of weight loss (Tp), and the temperature at final weight loss (Tf) in the first stage of degradation reaction move toward the high temperature side as the heating rate quickened. The weight loss rate increases significantly with increment of heating rate; the correlation between the weight loss rate (αp) of DTG peak and the heating rate is not obvious. The weight loss rate in the first stage (αf1) rises as the heating rate increases. The final weight loss rate in second stage (αf2) has no reference to heating rate; the weight loss rate of the rubber film is 99.9% at that time. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3196–3200, 2004
Modification of adhesive properties of a polyethylene film by photografting
Authors: El Kholdi O. , Lecamp L. , Lebaudy P. , Bunel C. , Alexandre S.
Published: March 2004

Graft polymerization of acrylic acid from monomer solutions in water or in bulk onto low‐density polyethylene film substrate was carried out by the method of continuous process under UV radiation. Effects of the nature of photoinitiator on acrylic acid grafting was first studied. One PI2 and two PI1 photoinitiators were used. Benzophenone was then retained for the following study. The influence of photoinitiator and monomer concentration was investigated by determining polymerization kinetics and grafted polymer amount. A study of surface wetting and morphological structure was then carried out on a bulk system and as a function of the photoinitiator concentration. Finally, such surface modification was studied with respect to its effect on the adhesion of an acrylic stick on its surface. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2803–2811, 2004
High‐performance epoxy hybrid nanocomposites containing organophilic layered silicates and compatibilized liquid rubber
Authors: Fröhlich J. , Thomann R. , Gryshchuk O. , Karger‐Kocsis J. , Mülhaupt R.
Published: March 2004

A mixture of two epoxy resins, tetraglycidyl 4,4′‐diaminodiphenyl methane and bisphenol‐A diglycidylether, cured with 4,4′‐diaminodiphenyl sulfone, was used as matrix material for high‐performance epoxy hybrid nanocomposites containing organophilicly modified synthetic fluorohectorite and compatibilized liquid six‐arm star poly(propylene oxide‐block‐ethylene oxide) (abbreviated as PPO). The hydroxy end groups of the poly(propylene oxide‐block‐ethylene oxide) were modified, yielding a six‐arm star PPO with an average of two pendant stearate chains, two phenol groups, and two hydroxy end groups. The alkyl chains of the stearate end groups played an important role in tailoring the polarity of the polymer. Its phenol end groups ensured covalent bonding between liquid polymer and epoxy resin. Two different organophilic fluorohectorites were used in combination with the functionalized PPO. The morphology of the materials was examined by transmission electron microscopy. The hybrid nanocomposites were composed of intercalated clay particles as well as separated PPO spheres in the epoxy matrix. As determined by dynamic mechanical analysis, the prepared composites possessed glass‐transition temperatures around 220°C. Although the tensile moduli remain unaltered, the tensile strengths of the hybrid materials were significantly improved. The relatively high fracture toughness of the neat resin, though, was not preserved for the hybrid resins. Scanning electron microscopy of the fracture surfaces revealed extensive matrix shear yielding for the neat resin, whereas the predominant fracture mode of the hybrid nanocomposites was crack bifurcation and branching. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3088–3096, 2004
Mechanical properties, morphological structure, and thermal behavior of dynamically photocrosslinked PP/EPDM blends
Authors: Tang Longxiang , Qu Baojun , Shen Xiaofeng
Published: March 2004

A dynamically photocrosslinked polypropylene (PP)/ethylene–propylene–diene (EPDM) rubber thermoplastic elastomer was prepared by simultaneously exposing the elastomer to UV light while melt‐mixing in the presence of a photoinitiator as well as a crosslinking agent. The effects of dynamic photocrosslinking and blend composition on the mechanical properties, morphological structure, and thermal behavior of PP/EPDM blends were investigated. The results showed that after photocrosslinking, tensile strength, modulus of elasticity, and elongation at break were improved greatly. Moreover, the notched Izod impact strength was obviously enhanced compared with corresponding uncrosslinked blend. Scanning electron microscopy (SEM) morphological analysis showed that for uncrosslinked PP/EPDM blends, the cavitation of EPDM particles was the main toughening mechanism; whereas for dynamically photocrosslinked blends, shear yielding of matrix became the main energy absorption mechanism. The DSC curves showed that for each dynamically photocrosslinked PP/EPDM blend, there was a new smaller melting peak at about 152°C together with a main melting peak at about 166°C. Dynamic mechanical thermal analysis (DMTA) indicated that the compatibility between EPDM and PP was improved by dynamic photocrosslinking. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3371–3380, 2004
Rheological and thermal properties of thermoplastic natural rubbers based on poly(methyl methacrylate)/epoxidized‐natural‐rubber blends
Authors: Nakason C. , Panklieng Y. , Kaesaman A.
Published: March 2004

Epoxidized natural rubbers (ENRs) with epoxide levels of 10, 20, 30, 40, and 50 mol % were prepared. The ENRs were later blended with poly(methyl methacrylate) (PMMA) with various blend formulations. The mixing torque of the blends was observed. The torque increased as the PMMA contents and epoxide molar percentage increased in the ENR molecules. Furthermore, the shear stress and shear viscosity of the polymer blends in the molten state increased as the ENR content and epoxide molar percentage increased in the ENR molecules. Chemical interactions between polar groups in the ENR and PMMA molecules might be the reason for the increases in the torque, shear stress, and viscosity. All the ENR/PMMA blends exhibited shear‐thinning behavior. This was observed as a decrease in the shear viscosity with an increase in the shear rate. The power‐law index of the blends decreased as the ENR contents and epoxide molar percentage increased in the ENR molecules. However, the consistency index (or zero shear viscosity) increased as the ENR contents and epoxide molar percentage increased. A two‐phase morphology was observed with scanning electron microscopy. The small domains of the minor components were dispersed in the major phase. For the determination of blend compatibility, two distinct glass‐transition‐temperature (Tg) peaks from the tan δ/temperature curves were found. Shifts in Tg to a higher temperature for the elastomeric phase and to a lower temperature for the PMMA phase were observed. Therefore, the ENR/PMMA blends could be described as partly miscible blends. According to the thermogravimetry results, the decomposition temperatures of the blends increased as the levels of ENR and the epoxide molar percentage increased. The chemical interactions between the different phases of the blends could be the reason for the increase. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3561–3572, 2004
Preparation, morphology, and mechanical properties of elastomers based on α,ω‐dihydroxy‐polydimethylsiloxane/polystyrene blends
Authors: Dong Jian , Liu Zonglin , Han Nianfeng , Wang Qin , Xia Yiran
Published: March 2004

α,ω‐Dihydroxy‐polydimethylsiloxane/polystyrene (PDMS/PS) blends were prepared by the solution polymerization of styrene (St) in the presence of α,ω ‐dihydroxy‐polydimethylsiloxane (PDMS), using toluene as solvent and benzoyl peroxide (BPO) as initiator. The PDMS/PS blends obtained by this method are a series of stable, white gums, which were vulcanized to elastomers at room temperature with methyl‐triethoxysilicane (MTES). The use level of MTES was far more than the necessary amount used to end‐link hydroxy‐terminated chains of PDMS, with the excess being hydrolyzed to crosslinked networks, which were similar to SiO2 and acted as filler. Investigations were carried out on the elastomeric materials by extraction measurement, swelling measurement, and scanning electron microscopy. The extraction data show that at each composition the amount of soluble fraction is less than expected and the difference between experimental and theoretical values becomes more and more significant as PS content increases. This is mainly due to the grafting of PS onto PDMS and the entanglement of PS in the interpenetrating polymer network (IPN), which consists of either directly linked PDMS chains or chains linked via PS grafts and is formed by free radical crosslinking of PDMS during the radical polymerization of St. PS grafted on PDMS is insoluble and PS entangled in the IPN is difficult to extract. Both render the soluble fraction to be less than expected. As the St content in preparing PDMS/PS blends increases, the probability of grafting PS onto PDMS also increases, which may subsequently produce a higher crosslinking level of PDMS networks that linked via PS grafts by radical crosslinking. As a result, not only the amount of insoluble PS increases but also PS entangled in the IPN is more difficult to extract. Scanning electron microscopy demonstrates that the elastomer system has a microphase‐separated structure and a certain amount of PS remains in the PDMS networks after extraction, which is in accordance with the extraction data. Moreover, the mechanical properties of the elastormeric materials have been studied in detail. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3542–3548, 2004
Synthesis and Morphine Enhancement Activity of N‐[5‐(2‐phenoxyphenyl)‐1, 3, 4‐oxadiazole‐2‐yl]‐N′‐phenylurea Derivatives
Authors: Rad Ali Almasi , Sheikhha Majid , Hosseini Rohollah , Tabatabaic Sayyed Abbas , Shafiee Abbas
Published: March 2004

The synthesis of N‐[5‐(2‐phenoxyphenyl)‐1, 3, 4‐oxadiazole‐2‐yl]‐N′‐phenylurea derivatives is reported. The structures of these compounds are supported by their IR, 1H‐NMR and mass spectra. Conformational analysis and superimposition of energy minima conformers of these compounds on L‐365, 260, a known 3‐ureido‐1, 4‐benzodiazepine CCK‐B antagonist, showed that the aromatic rings fell in the same contour. Morphine analgesia enhancement evaluation of the synthesized compounds in comparison with a control group showed that compounds 8a, 8c, 8h—8j, 8l, 8o have significant effects.
Antioxidant Properties of Novel Benzimidazole Retinoids
Authors: Ates‐Alagoz Zeynep , Can‐Eke Benay , Coban Tulay , Iscan Mumtaz , Buyukbingol Erdem
Published: March 2004

Our approach was to examine the antioxidant activity of novel retinoid derivatives containing the benzimidazole moiety. Their in vitro effects on rat liver microasomal, NADPH‐dependent lipid peroxidation levels and superoxide anion formation were determined. Lipid peroxidation in rat liver microsomes was reduced by some of the compounds in a dose‐dependent manner.
Non‐Thiol Farnesyltransferase Inhibitors: Utilization of the Near Aryl Binding Site by 5‐Arylacetylaminobenzophenones
Authors: Mitsch Andreas , Böhm Markus , Sattler Isabel , Schlitzer Martin
Published: March 2004

We recently described two novel aryl binding sites of farnesyltransferase. The arylacetyl residue was designed as an appropriate substituent for our benzo‐phenone‐based AAX‐peptidomimetic compound capable of occupying the near aryl binding site which is located next to the catalytic zinc ion. Non‐thiol farnesyl‐transferase inhibitors with micromolar to submicromolar activity were obtained.
Evolution, continuity, and disappearance of documents on a specific topic on the Web: A longitudinal study of “informetrics”
Authors: Bar‐Ilan Judit , Peritz Bluma C.
Published: March 2004

The present paper analyzes the changes that occurred to a set of Web pages related to “informetrics” over a period of 5 years between June 1998 and June 2003. Four times during this time span, in 1998, 1999, 2002, and 2003, we monitored previously located pages and searched for new ones related to the topic. Thus, we were able to study the growth of the topic, while analyzing the rates of change and disappearance. The results indicate that modification, disappearance, and resurfacing cannot be ignored when studying the structure and development of the Web.
Phenotypic expression of a family with multiple endocrine neoplasia type 2A due to a RET mutation at codon 618
Authors: Lindskog S , Nilsson O , Jansson S , Nilsson B , Illerskog A-C , Ysander L , Ahlman H , Tisell L-E
Published: March 2004

Background

Multiple endocrine neoplasia type 2A (MEN2A) is caused by missense mutations in the RET proto-oncogene on chromosome 10. This paper reports the phenotypic expression of a family with MEN2A, in which serine substitutes for cysteine at codon 618 in exon 10 of the RET gene. It was first claimed that medullary thyroid cancer (MTC) with this rare mutation led to mild disease; this has recently been updated to intermediate–high risk, based on stratified genetic information.

Methods

The family was mapped over six generations. In 1971 family members were invited to join a screening programme. Genetic testing was started in 1994.

Results

Twenty-two individuals with MTC were identified, 16 by the screening programme. One screened patient had a phaeochromocytoma and four had hyperparathyroidism. At surgery for MTC 12 patients had local tumour metastases and two young patients also had liver metastases. No screened patient died from MTC during a mean observation time of 19 years. Six other family members were diagnosed with MTC by signs and symptoms, five of whom died from MTC.

Conclusion

Because of the great interindividual differences in tumour aggressiveness within the family it is impossible to predict whether an individual gene carrier will have an aggressive MTC or not. This unpredictability is an additional argument, besides those obtained in stratified genetic studies, for operating on gene carriers at young age.
Late coronary stent thrombosis associated with exercise testing
Authors: Parodi Guido , Antoniucci David
Published: March 2004

We report a case of coronary stent thrombosis that occurred 6 months after the primary stenting of the left anterior descending coronary artery for acute myocardial infarction in a 75‐year‐old man. The reinfarction occurred the day after the demonstration of persistent optimal result of the percutaneous coronary intervention and immediately after exercise testing. A combined approach of a mechanical thrombus burden reduction by using AngioJet thrombectomy with adjunctive glycoprotein IIb/IIIa antagonist was performed, resulting in the complete removal of filling defects on the angiography. Catheter Cardiovasc Interv 2004;61:515–517. © 2004 Wiley‐Liss, Inc.
Sedimentation and Coalescence Profiles in Liquid‐Liquid Batch Settling Experiments
Authors: Yu G.‐Z. , Mao Z.‐S.
Published: March 2004

A simple mathematical method for predicting the phase separation profiles of a batch liquid‐liquid dispersion is developed based on the empirical description of drops resting at a liquid‐liquid plane interface. The inflexion time, at which the sedimentation zone vanishes, can be obtained by analysis of the coalescence profile. Therefore, the sedimentation profile can be predicted and the size of drop and interfacial area can be estimated. The experiments were carried out with an O/W‐type dispersion of kerosene‐water system in a 154 mm I.D. mixing vessel. The experimental results agree well with the model prediction. Other experimental data in the literature were also adopted for testing the model.
A Semi‐continuous Process for the Synthesis of Methyl Carbamate from Urea and Methanol
Authors: Sun J. , Yang B. , Lin H.
Published: March 2004

A semicontinuous process for the synthesis of methyl carbamate from urea and methanol was investigated in the autoclave without the catalyst. Some significant parameters were determined in terms of the methyl carbamate yield. The optimal reaction conditions were found at an initial molar ratio of methanol/urea of 6:1, a reaction temperature of 423 K, a flow rate of fresh methanol at 4 mL/min, a stirring speed of 800 rpm and a reaction time of 6 hours, respectively. A MC yield of 98.7 % was obtained at the optimal reaction conditions. Furthermore, the kinetics of this reaction were researched and the reaction activation energy was obtained as 110.498 kJ/mol. It was demonstrated that removing methanol containing ammonia from the autoclave and replacing it with continuously feeding fresh methanol resulted in a higher reaction rate and a high MC yield.
Mikrowellen‐ und Mikrowellen‐Vakuumtrocknung von Lebensmitteln
Authors: Regier M. , Knörzer K. , Erle U.
Published: March 2004

Die Verfahren der Mikrowellen‐ und Mikrowellen‐Vakuumtrocknung von Lebensmitteln werden näher beleuchtet. Ausgehend von einigen historischen Bemerkungen zur Entwicklung von Mikrowellen‐Erwärmungsverfahren werden die physikalischen Grundlagen, d. h. Elektromagnetismus, Wärme‐ und Stofftransport, anhand der bei diesen Prozessen wichtigsten physikalischen Stoffeigenschaften beschrieben. Darauf aufbauend wird gezeigt, welche Ansatzpunkte zur Beschreibung und Modellierung von Mikrowellenverfahren in der Literatur existieren. Nach einer Klassifikation industrieller Mikrowellentrockner werden Beispiele für heutige Anwendungen der Mikrowellentrocknung beschrieben. Die Literaturhinweise sollen Interessierten auch als Ausgangspunkt zur Recherche weitergehender Informationen zu Mikrowellentrocknungsverfahren dienen.
Einfluss von Antigefrierproteinen auf die Rekristallisation von Eis in Modelllösungen für Eiskrem
Authors: Gaukel V. , Spieß W. E. L.
Published: March 2004

No abstracts.
Lycopin‐ und β‐Carotinstabilität und ‐bioverfügbarkeit bei Möhrenprodukten
Authors: Mayer‐Miebach E. , Behsnilian D. , Regier M. , Schuchmann H. P.
Published: March 2004

No abstracts.
Herstellung flüssiger, wasserdispergierbarer Phytosterol‐Formulierungen zur Verbesserung der Dosiswirkung in Lebensmittelsystemen
Authors: Engel R. , Knorr D.
Published: March 2004

No abstracts.
Heißgasbehandlung von Gewürzen am Beispiel schwarzer Pfeffer
Authors: Bültermann R.
Published: March 2004

No abstracts.
The challenge of discrepancies in values among physicians, patients, and family members
Authors: Kissane David W.
Published: March 2004

Dignity, autonomy, integrity, and vulnerability constitute an excellent set of ethical principles fundamental to a conception of the human good upon which to consider questions of care for the terminally ill.

See article by Oh et al, this issue.
Soluble vascular endothelial growth factor receptor 1, and not receptor 2, is an independent prognostic factor in acute myeloid leukemia and myelodysplastic syndromes
Authors: Hu Qinglong , Dey Amanda L. , Yang Ying , Shen Yu , Jilani Iman B. , Estey Elihu H. , Kantarjian Hagop M. , Giles Francis J. , Albitar Maher
Published: March 2004

BACKGROUND

Vascular endothelial growth factor (VEGF) and its receptors (VEGFRs) are major regulators of angiogenesis, which plays a key role in the growth and dissemination of solid tumors and hematologic neoplasms.

METHODS

The authors measured the plasma concentrations of soluble VEGFR1 (sVEGFR1) and sVEGFR2 in 133 patients with acute myeloid leukemia (AML) and in 80 patients with myelodysplastic syndromes (MDS) at the time of initial presentation and compared clinical behaviors.

RESULTS

A reverse correlation was observed between plasma sVEGFR1 levels and the rate of complete remission (CR) in patients with AML, but not in patients with MDS. In contrast, increased plasma levels of sVEGFR2 were correlated with a lower CR rate in patients with MDS, but not in patients with AML. Cox regression model analysis demonstrated that plasma levels of sVEGFR1, but not sVEGFR2, were independent prognostic factors in both patients with AML and patients with MDS.

CONCLUSIONS

The findings suggest that different mechanisms are involved in the pathophysiology of AML and MDS. The concentration of sVEGFR1 and sVEGFR2 in plasma should be considered a significant factor in guiding antiangiogenic therapy for AML and MDS. They may play a role in the pharmacodynamics of therapeutic agents that are supposed to bind directly to these receptors. Cancer 2004. © 2004 American Cancer Society.
Stereological analysis of the mediodorsal thalamic nucleus in schizophrenia: Volume, neuron number, and cell types
Authors: Dorph‐Petersen Karl‐Anton , Pierri Joseph N. , Sun Zhuoxin , Sampson Allan R. , Lewis David A.
Published: March 2004

The mediodorsal thalamic nucleus (MD) is the principal relay nucleus for the prefrontal cortex, a brain region thought to be dysfunctional in schizophrenia. Several, but not all, postmortem studies of the MD in schizophrenia have reported decreased volume and total neuronal number. However, it is not clear whether the findings are specific for schizophrenia nor is it known which subtypes of thalamic neurons are affected. We studied the left MD in 11 subjects with schizophrenia, 9 control subjects, and 12 subjects with mood disorders. Based on morphological criteria, we divided the neurons into two subclasses, presumably corresponding to projection neurons and local circuit neurons. We estimated MD volume and the neuron number of each subclass using methods based on modern unbiased stereological principles. We also estimated the somal volumes of each subclass using a robust, but biased, approach. In addition, we investigated the left MD in four cynomolgus monkeys chronically exposed to haloperidol and in four control monkeys in order to assess the possible effects of antipsychotic medications. The three human subject groups did not differ in any of the measures. In addition, no differences were observed between the two groups of monkeys. Thus, these findings do not support the hypothesis that the MD is a locus of pathology in schizophrenia, although they cannot rule out important functional or structural changes in parameters not measured. Like other studies, this investigation is subject to the limitations involved in sampling from a heterogeneous population emphasizing the need to continue to improve the application of robust, unbiased techniques to quantitative studies of this complex brain disorder. J. Comp. Neurol. 472:449–462, 2004. © 2004 Wiley‐Liss, Inc.
Nitric oxide synthase expression and cell changes in dorsal root ganglia and spinal dorsal horn of developing and adult Rana esculenta indicate a role of nitric oxide in limb metamorphosis
Authors: Cristino Luigia , Florenzano Fulvio , Bentivoglio Marina , Guglielmotti Vittorio
Published: March 2004

Metamorphosis of amphibians requires reconfiguration of sensory and locomotor neural networks. In view of such plastic changes and implications of nitric oxide (NO) in neural developmental shaping, we examined via histochemistry and immunohistochemistry its synthetic enzyme nitric oxide synthase (NOS) in dorsal root ganglia (DRGs) and dorsal horn of the developing and adult frog Rana esculenta. In limb DRGs, NOS positivity was first and selectively detected just before limb bud appearance, increased during metamorphosis, and was then down‐regulated. In adulthood, NOS was expressed in some DRG neurons at all segmental levels. Similar features were detected in the dorsal horn neuropil. In limb DRGs, cell counts in Nissl‐stained sections revealed a twofold increase of differentiated neurons during metamorphosis and an additional twofold increase in adulthood. Perikaryal sizes in limb DRGs did not vary during metamorphosis but increased and were more heterogeneous in the adult frog, probably reflecting adaptation to body size. NOS and cell changes during metamorphosis were much less marked in DRGs at other levels. Carbocyanine tracing documented selective labeling of NOS‐expressing hindlimb DRG neurons from the spinal nerve at the time of initiation of hindlimb movements. The findings show that, in limb DRG neurons, NOS parallels cell differentiation and limb development during metamorphosis. The data also provide evidence of NOS expression in DRG cells innervating the hindlimbs when sensorimotor circuits become functionally mature. This study indicates a key role of NO production in the maturation of sensory functions that subserves in amphibians the transition from swimming to tetrapod locomotion. J. Comp. Neurol. 472:423–436, 2004. © 2004 Wiley‐Liss, Inc.
Immunohistochemical localization of aspartoacylase in the rat central nervous system
Authors: Madhavarao Chikkathur N. , Moffett John R. , Moore Roger A. , Viola Ronald E. , Namboodiri M.A. Aryan , Jacobowitz David M.
Published: March 2004

Aspartoacylase (ASPA; EC 3.5.1.15) catalyzes deacetylation of N‐acetylaspartate (NAA) to generate free acetate in the central nervous system (CNS). Mutations in the gene coding ASPA cause Canavan disease (CD), an autosomal recessive neurodegenerative disease that results in death before 10 years of age. The pathogenesis of CD remains unclear. Our working hypothesis is that deficiency in the supply of the NAA‐derived acetate leads to inadequate lipid/myelin synthesis during development, resulting in CD. To explore the localization of ASPA in the CNS, we used double‐label immunohistochemistry for ASPA and several cell‐specific markers. A polyclonal antibody was generated in rabbit against mouse recombinant ASPA, which reacted with a single band (∼37 kD) on Western blots of rat brain homogenate. ASPA colocalized throughout the brain with CC1, a marker for oligodendrocytes, with 92–98% of CC1‐positive cells also reactive with the ASPA antibody. Many cells were labeled with ASPA antibodies in white matter, including cells in the corpus callosum and cerebellar white matter. Relatively fewer cells were labeled in gray matter, including cerebral cortex. No astrocytes were labeled for ASPA. Neurons were unstained in the forebrain, although small numbers of large reticular and motor neurons were faintly to moderately stained in the brainstem and spinal cord. Many ascending and descending neuronal fibers were moderately stained for ASPA in the medulla and spinal cord. Microglial‐like cells showed faint to moderate staining with the ASPA antibodies throughout the brain by the avidin/biotin‐peroxidase detection method, and colocalization studies with labeled lectins confirmed their identity as microglia. The predominant immunoreactivity in oligodendrocytes is consistent with the proposed role of ASPA in myelination, supporting the case for acetate supplementation as an immediate and inexpensive therapy for infants diagnosed with CD. J. Comp. Neurol. 472:318–329, 2004. Published 2004 Wiley‐Liss, Inc.
The dorsolateral corticospinal tract in mice: An alternative route for corticospinal input to caudal segments following dorsal column lesions
Authors: Steward Oswald , Zheng Binhai , Ho Carole , Anderson Kim , Tessier‐Lavigne Marc
Published: March 2004

In rodents, the main contingent of corticospinal tract (CST) axons descends in the ventral part of the dorsal column. There is, however, a contingent of CST axons that descends in the dorsolateral column (the “dorsolateral corticospinal tract,” or DLCST). Here, we define some of the features of the DLCST by tracing CST projections following injections of biotinylated dextran amine into the sensorimotor cortex, assessing the distribution of DLCST axons and terminal arborizations in intact mice and in mice in which the main contingent of CST axons in the dorsal column had been transected. Axons of the DLCST diverge from the main tract at the pyramidal decussation, gather in fascicles in the dorsolateral gray matter below the spinomedullary junction, and project in a gradual trajectory laterally toward the dorsolateral column over the first few cervical segments. DLCST axons then project along the dorsolateral column to sacral levels, giving rise to collaterals that project into the gray matter. Labeled DLCST axons were most abundant in cervical segments, where they were often collected in fascicles, and progressively decreased in number in more caudal segments. Tracing of DLCST axons in mice with selective lesions of the dorsal column revealed that DLCST axons arborize extensively throughout the dorsal and ventral horns and that the overall territory that the DLCST axons invade is similar to the territory innervated by the CST axons in the main tract. Some DLCST axon arbors with varicosities are seen near large neurons in the ventral horn (presumed motoneurons). Substantial numbers of DLCST axons project across the midline to the gray matter on the contralateral side. Thus, the DLCST provides an alternate route for CST input to caudal segments, which is of particular relevance for studies of CST distribution and function following partial spinal cord injuries. J. Comp. Neurol. 472:463–477, 2004. © 2004 Wiley‐Liss, Inc.
A Green's function for steady‐state two‐dimensional isotropic heat conduction across a homogeneously imperfect interface
Authors: Ang W. T. , Choo K. K. , Fan H.
Published: March 2004

The problem of calculating the steady‐state two‐dimensional temperature field in a thermally isotropic bimaterial which has a homogeneously imperfect interface is considered. There is a temperature jump across the imperfect interface. To devise a boundary element method, which does not require the imperfect interface to be discretized, for the numerical solution of the problem, a special Green's function satisfying the appropriate interface condition is derived. A specific test problem is solved numerically using the boundary element method. Copyright © 2004 John Wiley & Sons, Ltd.
A model for parallel job scheduling on dynamical computer Grids
Authors: Goldman Alfredo , Queiroz Carlos
Published: March 2004

This work presents a model that allows the execution of parallel applications in a Grid environment. Our main focus is on how to share the idle cycles of clusters and computers to execute real parallel applications. We present a new model which introduces the notions of locality and adaptability. The locality is used for job allocation, and for job migration. The adaptability provides a simple mechanism to allow clusters to join or leave a Grid. We also propose the middleware architecture to implement the model, and provide some simulation results to show the main characteristics of the model. Copyright © 2004 John Wiley & Sons, Ltd.
Fine‐grained authorization for job execution in the Grid: design and implementation
Authors: Keahey K. , Welch V. , Lang S. , Liu B. , Meder S.
Published: March 2004

In this paper, we describe our work on enabling fine‐grained authorization for resource usage and management. We address the need of virtual organizations to enforce their own polices in addition to those of the resource owners, with regards to both resource consumption and job management. To implement this design, we propose changes and extensions to the Globus Toolkit's version 2 resource management mechanism. We describe the prototype and policy language that we have designed to express fine‐grained policies and present an analysis of our solution. Copyright © 2004 John Wiley & Sons, Ltd.
Grid computing and active services
Authors: Schulze B. , Madeira E. R. M.
Published: March 2004

Recent activities in Grid computing point in the direction of an open service architecture merging computational infrastructure with Grid services and Web services. We also see advantages in adding facilities offered by distributed object computing environments with their interoperable references and services. The use of open service architectures introduces the possibility of composing structures of nested services. In this paper we discuss architectural aspects of middleware for Grid computing based on an infrastructure of distributed clusters and/or also services, and an access portal as a demonstration project in progress. Copyright © 2004 John Wiley & Sons, Ltd.
Silent cerebral infarction in patients with type 2 diabetic nephropathy. Effects of antiplatelet drug dilazep dihydrochloride
Authors: Nakamura Tsukasa , Kawagoe Yasuhiro , Matsuda Takaharu , Ueda Yoshihiko , Ebihara Isao , Koide Hikaru
Published: March 2004

Background

To determine whether diabetic nephropathy is a risk factor for silent cerebral infarction and whether antiplatelet drug dilazep dihydrochloride decreases the occurrence of silent cerebral infarction in type 2 diabetes patients with microalbuminuria.

Methods

Two hundred four type 2 diabetes patients (124 men, 80 women; age, median 56 years, range 42–74 years) and 60 healthy age‐matched subjects (no diabetes, normal renal function) were recruited for brain magnetic resonance imaging. The diabetes patients included 40 without nephropathy (group A), 42 with microalbuminuria (20–200 µg/min) (group B), 44 with macroalbuminuria (>200 µg/min) and normal renal function (blood creatinine <132.7 µmol/L) (group C), 33 with chronic renal failure but not undergoing haemodialysis (blood creatinine >132.7 µmol/L; mean creatinine 335.9 µmol/L) (group D) and 45 undergoing haemodialysis (duration; median 4 years, range 3–6 years) (group E).

Results

Silent cerebral infarction was found in 20, 29, 34, 45, 53 and 8% of group A, B, C, D, E and control patients respectively. The incidence of silent cerebral infarction was increased with diabetic nephropathy. Thirty group B patients with no silent cerebral infarction were divided into two groups: (B1) 15 treated with dilazep dihydrochloride and (B2) 15 not treated with dilazep dihydrochloride. Treatment continued for 24 months. The incidence of silent cerebral infarction was significantly lower in the dilazep‐treated patients (6.7%) than in the untreated patients (33.3%) (p < 0.01).

Conclusions

These data suggest that diabetic renal dysfunction increases the risk of silent cerebral infarction and that dilazep dihydrochloride prevents its onset in early type 2 diabetic nephropathy patients. Copyright © 2004 John Wiley & Sons, Ltd.
Stem cell dynamics during growth, feeding, and starvation in the basal flatworm Macrostomum sp. (Platyhelminthes)
Authors: Nimeth Katharina T. , Mahlknecht Monika , Mezzanato Andrea , Peter Roland , Rieger Reinhard , Ladurner Peter
Published: March 2004

Development, growth, and regeneration in Macrostomum are based—as in all Platyhelminthes—on likely totipotent stem cells (neoblasts), basic for all Bilaterians. We demonstrate dynamics and migration of neoblasts during postembryonic development, starvation, and feeding of Macrostomum sp. Double labeling of S‐phase and mitotic cells revealed a fast cell turnover. Conflicting with recent results from planarians, we have some indication of slow cycling neoblasts. As in planarians, starvation dramatically reduced mitotic activity and a very basic level was maintained after 30 days of starvation. Afterward, feeding induced a dramatic immediate proliferative response probably caused by G2‐arrested neoblasts. The following 12 hr showed a significant mitotic decline, caused by the depletion of the G2 neoblast pool. Neoblasts that pass through S‐phase led to a maximum of mitoses after 48 hr. Our results allow deeper insight into cellular dynamics of an ancestral bilaterian stem cell system of a basal Platyhelminth. Developmental Dynamics 230:91–99, 2004. © 2004 Wiley‐Liss, Inc.
Implementing the SEA Directive: sectoral challenges and opportunities for the UK and EU
Authors: Sheate William R. , Byron Helen J. , Smith Steven P.
Published: March 2004

This paper examines the implementation of Directive 2001/42/EC on the assessment of the effects of certain plans and programmes on the environment (the ‘SEA Directive’) in the UK and draws out wider implications from the UK approach for implementation across the EU as a whole. The paper begins with a brief overview of the UK's progress in implementing the directive in relation to three key issues: establishing the legal framework for implementing the directive; identifying those plans and programmes to which the directive will apply and providing support for implementation (e.g. through guidance and training). The paper then focuses on three sectors – land use planning, water and energy – and discusses key issues affecting implementation in each sector. In the land use planning sector, for example, a key issue is the incorporation of the SEA Directive's requirements into a wider sustainability appraisal process, which addresses economic and social as well as environmental concerns. The sectoral comparison is followed by a discussion of the issues confronting the UK and the potential lessons for the EU as a whole and a series of recommendations to guide implementation. Copyright © 2004 John Wiley & Sons, Ltd and ERP Environment.
SEA in Swedish transportation policy‐making and planning — political ambitions and practice
Authors: Brokking Peter , Crona Jan Schmidtbauer , Eriksson Inga‐Maj , Balfors Berit
Published: March 2004

Since the mid‐1990s, the aim to incorporate SEA into Swedish strategic transportation planning has been repeatedly expressed in government documents and directives. To support a successful implementation, efforts have been made to develop tools and methods for the integration of SEA into strategic transportation planning. These efforts concern, for example, the application of SEA in corridor development and long‐term transportation planning. The practical experiences of SEA in strategic transportation planning have been influenced by the ambiguity of the scope and structure of SEA. In this paper the process of implementing the SEA in Swedish transportation planning will be reviewed. The review relates to political ambitions and practice, and highlights the methodological development of SEA applications in the Swedish transport sector. Copyright © 2004 John Wiley & Sons, Ltd and ERP Environment.
A Stereodivergent Approach to 5a‐Carba‐α‐D‐gluco‐, ‐α‐D‐galacto and ‐β‐L‐gulopyranose Pentaacetates from D‐Mannose, Based on 6‐exo‐dig Radical Cyclization and Barton−McCombie Radical Deoxygenation
Authors: Gómez Ana M. , Moreno Eduardo , Valverde Serafín , López J. Cristóbal
Published: March 2004

The three carbasugars, 5a‐carba‐α‐D‐gluco‐, ‐α‐D‐galacto and ‐β‐L‐gulopyranose pentaacetates 42, 35 and 28 respectively, have been prepared in a stereodivergent manner from D‐mannose. Alkynyl derivatives of 2,3:4,6‐di‐O‐isopropylidene‐D‐mannopyranose, which are homologated at C‐1 by reaction with trimethylsilylacetylide, undergo a 6‐exo‐dig radical cyclization, from a radical located at C‐5, to yield a mixture of highly functionalized exo‐methylenecyclohexanes. Ozonolysis of the exocyclic double bond in the latter generated cyclohexanones which, upon stereoselective reduction of the carbonyl moiety followed by site‐selective deoxygenation either at position C‐4 or C‐5a (parent carbohydrate numbering), afforded the title carbasugars. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Straightforward Synthesis of Aromatic Polycyclic Terpenoids through Biomimetic Cascade Cyclizations Triggered by Photochemical Electron Transfer
Authors: Rosales Viale , Zambrano Jorge , Demuth Martin
Published: March 2004

Photoinduced biomimetic cascade cyclizations of suitably functionalized terpenoid arylpolyalkenes via radical cationic intermediates represent a powerful route to polycyclic compounds in a single operational step. In all cases examined, the radical cation, created selectively and exclusively at the ψ‐polyalkene position, is trapped in anti‐Markovnikov fashion by water, liberating a free radical site, which ultimately initiates cascade‐style bond formation to afford the all‐chair polycyclic conformation containing one aromatic moiety. The products, some of which are podocarpic‐type structures 17−19, are beneficially 3β‐hydroxylated. Mechanistically, the reaction is probably initiated by a radical cation trapped by water prior to the cyclization event, which is driven by a pure radical‐type process. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)