bluuebunny/crossref_metadata_2025 huggingface dataset:
Classification of Clear-Cell Sarcoma as a Subtype of Melanoma by Genomic Profiling
Authors: Segal Neil H. , Pavlidis Paul , Noble William S. , Antonescu Cristina R. , Viale Agnes , Wesley Umadevi V. , Busam Klaus , Gallardo Humilidad , DeSantis Dianne , Brennan Murray F. , Cordon-Cardo Carlos , Wolchok Jedd D. , Houghton Alan N.
Published: April 2003

Purpose: To develop a genome-based classification scheme for clear-cell sarcoma (CCS), also known as melanoma of soft parts (MSP), which would have implications for diagnosis and treatment. This tumor displays characteristic features of soft tissue sarcoma (STS), including deep soft tissue primary location and a characteristic translocation, t(12;22)(q13;q12), involving EWS and ATF1 genes. CCS/MSP also has typical melanoma features, including immunoreactivity for S100 and HMB45, pigmentation, MITF-M expression, and a propensity for regional lymph node metastases.

Materials and Methods: RNA samples from 21 cell lines and 60 pathologically confirmed cases of STS, melanoma, and CCS/MSP were examined using the U95A GeneChip (Affymetrix, Santa Clara, CA). Hierarchical cluster analysis, principal component analysis, and support vector machine (SVM) analysis exploited genomic correlations within the data to classify CCS/MSP.

Results: Unsupervised analyses demonstrated a clear distinction between STS and melanoma and, furthermore, showed that CCS/MSP cluster with the melanomas as a distinct group. A supervised SVM learning approach further validated this finding and provided a user-independent approach to diagnosis. Genes of interest that discriminate CCS/MSP included those encoding melanocyte differentiation antigens, MITF, SOX10, ERBB3, and FGFR1.

Conclusion: Gene expression profiles support the classification of CCS/MSP as a distinct genomic subtype of melanoma. Analysis of these gene profiles using the SVM may be an important diagnostic tool. Genomic analysis identified potential targets for the development of therapeutic strategies in the treatment of this disease.
Mediastinal Lymph Node Clearance After Docetaxel-Cisplatin Neoadjuvant Chemotherapy Is Prognostic of Survival in Patients With Stage IIIA pN2 Non–Small-Cell Lung Cancer: A Multicenter Phase II Trial
Authors: Betticher Daniel C. , Hsu Schmitz Shu-Fang , Tötsch Martin , Hansen Eva , Joss Christine , von Briel Christian , Schmid Ralph A. , Pless Miklos , Habicht James , Roth Arnaud D. , Spiliopoulos Anastase , Stahel Rolf , Weder Walter , Stupp Roger , Egli Fritz , Furrer Markus , Honegger Hanspeter , Wernli Martin , Cerny Thomas , Ris Hans-Beat
Published: April 2003

Purpose: A multicenter, phase II trial investigated the efficacy and toxicity of neoadjuvant docetaxel-cisplatin in locally advanced non–small-cell lung cancer (NSCLC) and examined prognostic factors for patients not benefiting from surgery.

Patients and Methods: Ninety patients with previously untreated, potentially operable stage IIIA (mediastinoscopically pN2) NSCLC received three cycles of docetaxel 85 mg/m2 day 1 plus cisplatin 40 mg/m2 days 1 and 2, with subsequent surgical resection.

Results: Administered dose-intensities were docetaxel 85 mg/m2/3 weeks (range, 53 to 96) and cisplatin 95 mg/m2/3 weeks (range, 0 to 104). The 265 cycles were well tolerated, and the overall response rate was 66% (95% confidence interval [CI], 55% to 75%). Seventy-five patients underwent tumor resection with positive resection margin and involvement of the uppermost mediastinal lymph node in 16% and 35% of patients, respectively (perioperative mortality, 3%; morbidity, 17%). Pathologic complete response occurred in 19% of patients with tumor resection. In patients with tumor resection, downstaging to N0–1 at surgery was prognostic and significantly prolonged event-free survival (EFS) and overall survival (OS; P = .0001). At median follow-up of 32 months, the median EFS and OS were 14.8 months (range, 2.4 to 53.4) and 33 months (range, 2.4 to 53.4), respectively. Local relapse occurred in 27% of patients with tumor resection, with distant metastases in 37%. Multivariate analyses identified mediastinal clearance (hazard ratio, 0.22; P = .0003) and complete resection (hazard ratio, 0.26; P = .0006) as strongly prognostic for increased survival.

Conclusion: Neoadjuvant docetaxel-cisplatin is effective and tolerable in stage IIIA pN2 NSCLC. Resection is recommended only for patients with mediastinal downstaging after chemotherapy.
Pathology of Human Influenza A (H5N1) Virus Infection in Cynomolgus Macaques (Macaca fascicularis)
Authors: Kuiken T. , Rimmelzwaan G. F. , Van Amerongen G. , Osterhaus A. D. M. E.
Published: April 2003

Infection with influenza A (H5N1) virus, which has not been associated with respiratory disease in humans previously, caused clinical signs of acute respiratory distress syndrome and multiple-organ dysfunction syndrome with high mortality in humans in Hong Kong in 1997. To study the pathogenesis of this disease, we infected four cynomolgus monkeys ( Macaca fascicularis) with 2.5 × 104 median tissue culture infectious dose (TCID50) of influenza virus A/Hong Kong/156/97 (H5N1) and euthanatized them 4 or 7 days after infection. The main lesion was a necrotizing broncho-interstitial pneumonia (4/4) similar to those found in primary influenza virus pneumonia in humans, with desquamation of respiratory epithelium (4/4), intra-alveolar hemorrhage (4/4), hyaline membrane formation (2/4), and infiltration with neutrophils and macrophages (4/4). Lesions in other organs consisted of a suppurative tonsillitis (2/4) and necrosis in lymphoid organs (1/4), kidney (1/4), and liver (1/4). By immunohistochemistry, influenza virus antigen was limited to pulmonary tissue (4/4) and tonsils (2/4). Based on these results, we suggest that the cynomolgus monkey is a suitable animal model for studying the pathogenesis of human H5N1 virus infection and that multiple-organ dysfunction syndrome in this disease may be caused by diffuse alveolar damage from virus replication in the lungs alone.
Symmetric Focal Degeneration in the Cerebellar and Vestibular Nuclei in Swine Caused by Ingestion of Aeschynomene indica Seeds
Authors: Riet-Correa F. , Timm C. D. , Barros S. S. , Summers B. A.
Published: April 2003

A vestibulocerebellar disorder was observed in 2- to 4-month-old swine after consumption of broken rice contaminated with 13% Aeschynomene indica seeds. Affected animals recovered in 2–14 days after removal of the contaminated food. To reproduce the syndrome, 10 pigs were fed 13% A. indica seeds in commercial pig ration or rice. They showed clinical signs similar to those observed in the spontaneous cases, 1 hour to 6 days after ingestion. Three pigs recovered after the withdrawal of the contaminated food. The others were killed. Two pigs that were fed for 25 days with food containing 3% and 6% seeds and two control pigs did not show clinical signs. Histologic lesions were characterized by symmetric focal degeneration in the cerebellar and vestibular nuclei. The initial lesion, observed 24 hours after the first ingestion, was characterized by vacuolation of the neuropil. Subsequently, there was progressive loss of parenchyma, vascular reaction, a few small spheroids, astrocytosis, and accumulation of gitter cells. The brains from four pigs were perfused with a buffered solution of glutaraldehyde-paraformaldehyde 12–48 hours after they started to ingest the seeds. No ultrastructural lesions were observed in the cerebellar nuclei after 12 hours of seed consumption. At 24 hours, endothelial cells and pericytes were separated by empty spaces from astrocyte foot processes, suggesting perivascular edema. The astrocytes were enlarged, consistent with intracellular fluid accumulation. These results suggest that A. indica seeds are toxic, causing functional derangement of the vestibulocerebellar system, followed by alterations in the microvasculature in the cerebellar and vestibular nuclei.
Squamous Cell Carcinoma of the Anal Sac in Five Dogs
Authors: Esplin D. G. , Wilson S. R. , Hullinger G. A.
Published: April 2003

Tumors of the perianal area of dogs are common and include multiple tumor types. Whereas perianal adenomas occur often, adenocarcinomas of the apocrine glands of the anal sac occur less frequently. A review of the literature revealed no reports of squamous cell carcinomas arising from the epithelial lining of the anal sac. Squamous cell carcinomas originating from the lining of the anal sac were diagnosed in five dogs. Microscopically, the tumors consisted of variably sized invasive nests and cords of epithelial cells displaying squamous differentiation. Four of the five dogs were euthanatized because of problems associated with local infiltration by the tumors. In the fifth dog, there was no evidence of tumor 7 months after surgical removal, but further follow up was not available.
Synthesis and characterization of novel crosslinked polyurethane–acrylate electrolyte
Authors: Ren Tianbin , Luo Yinpei , Huang Xiaobin , Tang Xiaozhen
Published: April 2003

Flexible, transparent, and crosslinked polymer films were synthesized by polymerization of PEG‐modified urethane acrylate using a simple method. A series of novel solid polymer electrolytes and gel electrolytes were prepared based on this type of polymer film. To understand the interactions among salt, solvent, and polymer, the swelling behaviors of the crosslinked polymer in pure propylene carbonate (PC) and liquid electrolyte solutions (LiClO4/PC) were investigated. The results showed that the swelling rate in the electrolyte solution containing moderate LiClO4 was greater than that in pure PC. Thermogravimetric analysis (TGA) also supported the interaction between the solvent and polymer. The morphology and crystallinity of the crosslinked polymer and polymer electrolytes were studied using atomic force microscopy (AFM) and wide‐angle X‐ray diffraction (WAXD) spectroscopy. The effects of the content of the electrolyte solution on the ionic conductivity of gel electrolytes were explored. The dependence of the conductivity on the amount of the electrolyte solution was nonlinear. With a different content of the plasticizer, the ionic conduction pathway of the polymer electrolytes would be changed. The best ionic conductivity of the gel electrolytes, which should have good mechanical properties, was 4 × 10r−3 S cm−1 at 25°C. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 340–348, 2003
Melt rheological behavior of intimately mixed short sisal–glass hybrid fiber‐reinforced low‐density polyethylene composites. I. Untreated fibers
Authors: Kalaprasad G. , Mathew G. , Pavithran C. , Thomas Sabu
Published: April 2003

The melt rheological behavior of intimately mixed short sisal–glass hybrid fiber‐reinforced low‐density polyethylene composites was studied with an Instron capillary rheometer. The variation of melt viscosity with shear rate and shear stress at different temperatures was studied. The effect of relative composition of component fibers on the overall rheological behavior also was examined. A temperature range of 130 to 150°C and shear rate of 16.4 to 5470 s−1 were chosen for the analysis. The melt viscosity of the hybrid composite increased with increase in the volume fraction of glass fibers and reached a maximum for the composite containing glass fiber alone. Also, experimental viscosity values of hybrid composites were in good agreement with the theoretical values calculated using the additive rule of hybrid mixtures, except at low volume fractions of glass fibers. Master curves were plotted by superpositioning shear stress and temperature results. The breakage of fibers during the extrusion process, estimated by optical microscopy, was higher for glass fiber than sisal fiber. The surface morphology of the extrudates was analyzed by optical and scanning electron microscopy. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 432–442, 2003
Preparation and characterization of a novel responsive hydrogel with a β‐cyclodextrin‐based macromonomer
Authors: Liu Yu‐Yang , Fan Xiao‐Dong
Published: April 2003

Based on a combination of poly(N‐isopropylacrylamide), which could respond to an external temperature, and β‐cyclodextrin (β‐CD), which could form a molecular inclusion complex, a novel hydrogel, having both thermal and pH sensitivities and containing β‐CD and N‐isopropylacrylamide (NIPA) segments, was synthesized. For the incorporation of β‐CD into the polymer network, a macromonomer was prepared first by the reaction of a β‐CD‐based polymer with maleic anhydride in dimethylformamide and then by copolymerization with NIPA in an aqueous solution. Elemental analysis, IR spectroscopy, differential scanning calorimetry, and swelling measurements were employed for the characterization of the hydrogel chain structure and its physical properties. With methyl orange as a model compound in inclusion tests, it was found that the hydrogel not only possessed a remarkable supramolecular inclusion ability (with respect to that of the small molecule cyclodextrin) but also could sensitively respond to various external stimuli, including the temperature, pH, and ionic strength. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 361–367, 2003
Determination of the reactivity ratios for acrylonitrile/N‐vinylpyrrolidone copolymerization systems
Authors: Hou Chen , Wang Cheng‐Guo , Cai Hua‐Su , Zhang Wang‐Xi
Published: April 2003

The effects of the copolymerization system on the monomer reactivity ratios for a copolymer of acrylonitrile with N‐vinylpyrrolidone was studied for contrast. The values of the monomer reactivity ratios were calculated by the Kelen–Tudos method. The reactivity ratios in the aqueous suspension polymerization system were similar to those in the solution polymerization system at polymerization conversions of less than 6% [reactivity ratio of acrylonitrile (rAN) = 0.438 ± 0.015, reactivity ratio of N‐vinylpyrrolidone (rN‐VP) = 2.28 ± 0.02]. As conversion of more than 12%, the changes in the monomer reactivity ratios became less prominent (rAN = 0.651, rN‐VP = 1.98). In the water‐rich reaction medium [H2O/dimethylsulfoxide (DMSO) > 60/40], the monomer reactivity ratios were approximately equivalent to those in the aqueous suspension polymerization system. In the DMSO‐rich reaction medium (DMSO/H2O > 60/40), the reactivity ratios were similar to those in the solution polymerization system. With an increase in the polarity of the solvent, the values of the reaction ratios both decreased. The values of the reaction ratios gradually tended toward 1 with increasing copolymerization temperature. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 422–425, 2003
Dynamic mechanical and thermal analyses of magnetic particle and metal evaporated tapes and their individual layers
Authors: Ma Tiejun , Bhushan Bharat
Published: April 2003

The mechanical and thermal properties of magnetic tapes and their individual layers strongly affect the tribology of the magnetic head–tape interface. Dynamic mechanical analysis and thermomechanical analysis tests were performed on magnetic tapes, tapes with front coat or back coat removed, substrates (with front and back coats removed), and never‐coated virgin films of the substrates. Storage modulus and loss tangent were obtained at a frequency range from 0.016 to 28 Hz, and at a temperature range from −50 to 150 or 210°C. Coefficients of thermal expansion (CTE) of various samples were measured at a temperature range from 30 to 70°C. The tapes used in this research include two magnetic particle (MP) tapes and two metal evaporated (ME) tapes based on poly(ethylene terephthalate) and poly(ethylene naphthalate) substrates. The master curves of storage modulus for these samples were generated for a frequency range from 10−20 to 1015 Hz. The effect of the tape manufacturing process on the dynamic mechanical properties of substrates was analyzed by comparing the data for the substrates (with front and back coats removed) and the never‐coated virgin films. A model based on the rule of mixtures was developed to determine the storage modulus, complex modulus, and CTE for the front coat and back coat of MP and ME tapes. To validate the procedure, data for these individual layers were then used to calculate the corresponding properties of the finished tape. The predicted results were compared with the experimental measurements. The data obtained in the study are also discussed in light of previously published lateral contraction, Poisson's ratio, CTE, and CHE (coefficient of hygroscopic expansion) data. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 548–567, 2003
Kinetic of epoxy resin formation by high‐performance liquid chromatography
Authors: Dopico García M. S. , González Rodríguez M. V. , Díez Redondo F. J. , López Lago J. , Barral Losada L.
Published: April 2003

This article is focused on the following of the cure of an epoxy resin by high‐performance liquid chromatography (HPLC) and the comparison of the data obtained with those obtained by differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) techniques usually employed for characterize curing processes. A reversed‐phase HPLC method with UV detection is developed to study the kinetic of the curing reaction of diglycidyl ether of bisphenol A (DGEBA) with 1,3‐cyclohexanebismethylamine (1,3‐BAC) at 60, 70, and 80°C, before and after gelation. The limits of quantification obtained permit the application of the proposed method until the last steps of the formation kinetic. HPLC and DSC analysis show a good correlation. The gel conversions obtained by HPLC and DMA agree well. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 497–504, 2003
The first thalamocortical synapses are made in the cortical plate in the developing visual cortex of the wallaby (Macropus eugenii)
Authors: Pearce Amy R. , Marotte Lauren R.
Published: April 2003

The time course of development and laminar distribution of thalamocortical synapses in the visual cortex of the marsupial mammal the wallaby (Macropus eugenii) has been studied by electron microscopy from the time of afferent ingrowth to the appearance of layer 4, the main target for thalamic axons. Axons were labeled from the thalamus by a fluorescent carbocyanine dye in fixed tissue or by transneuronal transport of horseradish peroxidase conjugated to wheat germ agglutinin from the eye. Thalamic axons first reached the cortex 2 weeks after birth and grew into the developing cortical plate without a waiting period in the subplate. The first thalamocortical synapses were detected 2 weeks later solely throughout the loosely packed zone of the cortical plate, where layer 6 cells previously have been shown to reside. As the thickness of the cortex increased with age, thalamocortical synapses were increasingly prevalent in the loosely packed zone of the cortical plate. With the appearance of layer 4, thalamocortical synapses were found there as well as in the marginal zone and layer 6. There was no evidence for an early population of thalamocortical synapses in the subplate. The first synapses made by thalamic axons were in a region containing layer 6 cells, one of their normal targets in the mature cortex. J. Comp. Neurol. 461:205–216, 2003. © 2003 Wiley‐Liss, Inc.
Relay of visual information to the lateral geniculate nucleus and the visual cortex in albino ferrets
Authors: Akerman Colin J. , Tolhurst David J. , Morgan James E. , Baker Gary E. , Thompson Ian D.
Published: April 2003

The abnormal organization of the central visual pathways in the albino ferret has been characterized anatomically and physiologically. Recordings in dorsal lateral geniculate nucleus of the albino ferret show that lamina A1, which receives an aberrant projection from the contralateral eye, contains an extensive representation of the ipsilateral visual hemifield with receptive fields located up to 35 degrees from the vertical meridian. This is not the case in pigmented ferrets, for which the vast majority of units, activated through either the contralateral or ipsilateral eye, have receptive fields confined to the contralateral hemifield. The few fields found in the ipsilateral hemifield are driven through the contralateral eye and none is more than 10 degrees from the midline. Cortical topography was studied by making closely spaced electrode penetrations across the area 17/18 border. In pigmented animals, the reversal of topography at the border is characterized by units with receptive fields centered a few degrees into the ipsilateral hemifield. In 22 of 25 albinos, the “Boston” aberrant topography was found: the representation of the vertical meridian is within area 17, rather than at the area 17/18 border. Instead, at the area 17/18 border, there is a reversal in the topographic progression at up to 30 degrees into the ipsilateral hemifield. This pattern was most pronounced in the upper visual field. In agreement with the “Boston” physiology, injections of retrograde tracer made in area 17 usually label neurons in either lamina A or the part of lamina A1 that is aberrantly innervated by the contralateral eye. A column of labeled cells extending through all geniculate layers is rarely seen in albinos, although this is commonly the pattern in pigmented ferrets. J. Comp. Neurol. 461:217–235, 2003. © 2003 Wiley‐Liss, Inc.
Sol–gel‐derived amperometric glucose biosensor based on covalent attachment of toluidine blue O to carrier
Authors: Qian Junmin , Li Xuxiang , Huang Haiyan
Published: April 2003

An amperometric‐mediated glucose biosensor has been fabricated by immobilizing glucose oxidase (GOx) and mediator toluidine blue O (TBO) to a functional sol–gel thin layer on the surface of a platinum electrode via the cross‐linking agent glutaraldehyde. The functional sol–gel thin layer was synthesized through the hydrolysis and polycondensation of γ‐aminopropylmethyldimethoxysilane (APMDMOS) and tetramethoxysilicane (TMOS). GOx and TBO were covalently attached to carrier sol–gel material based on the interaction between the aldehyde group of glutaraldehyde and the amino group of GOx, TBO and carrier. Covalent immobilization eliminates leakage of the sensing reagent and mediator from the carrier. Cyclic voltammetry was employed to demonstrate the feasibility of electron transfer between the active site of sol–gel‐immobilized GOx and the surface of a platinum electrode. The calibration curve of glucose was linear in the range from 1 to 8 mmol/l, with a detection limit of 5 × 10−2 mmol/l. The lifetime of the biosensor was 30 days. Copyright © 2003 John Wiley & Sons, Ltd.
Asymmetric hydrogenation of diketones catalyzed by magnesium oxide‐supported chitosan–Rh complex
Authors: Zhou Da‐Qing , He Man , Zhang Yan‐Hong , Huang Mei‐Yu , Jiang Ying‐Yan
Published: April 2003

MgO‐supported chitosan–Rh complex (MgO‐CS‐Rh) has been prepared and found to be a highly stereoselective catalyst for the asymmetric hydrogenation of some diketones to corresponding chiral alcohols, such as 2,3‐butanedione to (2S,3S)‐(+)‐2,3‐butanediol and 2,4‐pentanedione to (2S,4S)‐(+)‐2,4‐pentanediol at room temperature and under 1 atm H2. The optical yield was greatly affected by the Rh content in the complex, the solvent and the reaction temperature. The optical yields of (2S,3S)‐(+)‐2,3‐butanediol and (3S,4S)‐(+)‐2,4‐pentanediol obtained were 87% and 81.2%, respectively. The chiral chitosan–Rh complex catalyst was very easy to prepare, and could be reused without noticeable change in its optical catalytic activity. Copyright © 2003 John Wiley & Sons, Ltd.
Enzymatic polymerization of aniline and phenol derivatives catalyzed by horseradish peroxidase in dioxane(II)
Authors: Shan Jinyu , Han Liyou , Bai Fenglian , Cao Shaokui
Published: April 2003

Aminophenols, methoxyanilines and 1‐naphthylamine were polymerized via the catalysis of horseradish peroxidase in dioxane at ambient conditions by using hydrogen peroxide as the oxidant. Polymers formed in good yields when using double the amount of the oxidant. The molecular weight of the polymers was determined by gel permeation chromatography, and the polymer structures were characterized by using nuclear magnetic resonance and infrared techniques. The polymerization of aminophenols and 1‐naphthylamine gave relatively high yields, while the polymer yields of methoxyanilines were very low. Except for 4‐methoxyaniline giving 23.5% yield, 2‐ and 3‐methoxyaniline gave < 20% and < 10% yield respectively. The polymer of 2‐aminophenol was characterized as a linear, phenoxazine‐like structure, while poly(4‐aminophenol) has a linear, meta‐oriented structure with the preservation of a hydroxyl group. Both of these are very different to those formed by chemical or electrochemical methods. Poly(3‐aminophenol) and poly(1‐naphthylamine) formed by enzymatic polymerization have very complicated structures. UV‐vis spectra and the cyclic voltammograms of the polymers produced were also examined. It has been proved that poly(2‐aminophenol) and poly(4‐aminophenol) have electroactivity with respect to a saturated HgCl2 electrode in 1 M HCl. Copyright © 2003 John Wiley & Sons, Ltd.
The synthesis and characterization of polyurethane/clay nanocomposites
Authors: Zhang Xinmin , Xu Rongjing , Wu Zenggang , Zhou Chixing
Published: April 2003

The water absorption of montmorillonite was studied using TGA and FTIR, and a removal method through boiling with toluene was investigated. PU/MMT was synthesized and its morphology, thermal dynamic mechanical properties and tensile behaviour were investigated by WAXD, FTIR, DMTA and Instron techniques. We find that, compared with the PU matrix, the intercalated PU/MMT nanocomposite was reinforced and toughened by the addition of nanometer‐size MMT layers. Copyright © 2003 Society of Chemical Industry
γ‐Crystalline form of nylon‐10,10 in nylon‐10,10–montmorillonite nanocomposite
Authors: Zhang Guosheng , Li Yongjin , Yan Deyue
Published: April 2003

Wide‐angle X‐ray diffraction (WAXD) and variable temperature WAXD spectroscopy and Fourier‐transform infrared (FTIR) spectrometry were used to identify the γ‐crystalline form of nylon‐10,10 in the nanocomposite of nylon‐10,10 and montmorillonite. A new diffraction peak at 2θ = 22° was observed in the WAXD pattern of the nanocomposite as compared with nylon‐10,10, and the data of variable temperature WAXD indicated that it was the characteristic peak of γ‐crystalline form of nylon‐10,10. The amide VI band at 624 cm−1 was also observed in the FTIR spectrum of the nanocomposite, which is characteristic of γ‐crystalline nylon. In addition, the shoulder peak at 1553 cm−1 can be assigned to the amide II band of γ‐crystalline form of nylon‐10,10. Copyright © 2003 Society of Chemical Industry
Catalytic synthesis and characterization of an alternating copolymer from carbon dioxide and propylene oxide using zinc pimelate
Authors: Zhu Q , Meng YZ , Tjong SC , Zhang YM , Wan W
Published: April 2003

New zinc pimelate catalysts used for copolymerization of carbon dioxide and propylene oxide have been synthesized in high yield by a magnetic stirring method. The regular molecular structure of the zinc pimelate was confirmed by Fourier‐transform infrared spectroscopy and wide‐angle X‐ray diffraction techniques. Accordingly, poly(propylene carbonate) (PPC) can be synthesized from carbon dioxide and propylene oxide using these zinc pimelate catalysts. High catalytic efficiency (95.2 gram polymer per gram catalyst or 21 300 g of polymer per mole of zinc) was achieved by optimizing the PO/catalyst ratio. NMR measurement revealed that the PPC synthesized had an alternating copolymer structure. The thermal properties of PPC were determined by modulated differential scanning calorimetry and thermogravimetric analysis. The results demonstrated that the PPC copolymer exhibited an extremely high glass transition temperature of 44.27 °C and decomposition temperature of 257 °C, comparable with values reported in literature. Copyright © 2003 Society of Chemical Industry
Synthesis of polymer–inorganic hybrid nanoparticles via radical polymerization initiated by surface‐immobilized photoiniferter
Authors: Bai Jie , Qiu Kun‐Yuan , Wei Yen
Published: April 2003

Polymer–inorganic hybrid nanoparticles were prepared through radical photo‐polymerization of methyl methacrylate initiated by N,N‐diethyldithiocarbamyl surface functionalized silica nanoparticles under UV irradiation at ambient temperature. IR analysis and UV spectroscopy confirmed the occurrence of Et2NCS2—end groups on the resulting poly(methyl methacrylate), and the morphology of these hybrid nanoparticles was observed directly by means of tapping mode atomic force microscopy (AFM). Copyright © 2003 Society of Chemical Industry
Filler effect on polymerization kinetics and phase separation in polymer blends formed in situ
Authors: Lipatov Yu S , Kosyanchuk L V , Nesterov A E , Antonenko O I
Published: April 2003

The kinetics of formation of a mixture of two polymers [poly(methyl methacrylate) and polyurethane] in situ in the course of two simultaneously proceeding reactions was studied in the presence of various amount of a filler (fumed silica). It was shown that the filler affects the rates of both reactions. In addition, the filler exerts an influence on the phase separation induced by the chemical reaction increasing the amount of a filler increases the time for the onset of phase separation. The effects observed may be explained both by the increase in the viscosity of the reaction system due to introduction of a filler and by selective adsorption of reaction system components at the interface with filler particles. In all cases, phase separation in the early stages of reaction proceeds in a four‐component system (two polymers formed and two initial compounds) and obeys the spinodal mechanism. It is also shown that the final morphology is determined far from the end of the reaction and before establishing the equilibrium state.

© 2003 Society of Chemical Industry
Fractional occupation numbers and spin density functional calculations of degenerate systems
Authors: Takeda R. , Yamanaka S. , Yamaguchi K.
Published: April 2003

We implemented ab initio self‐consistent field (SCF) fractional occupation numbers (FON) calculation with Dunlap's interpolation scheme for the twisted ethylene, which is a prototype molecule of a σ–π biradical system. The calculational results are compared with those of complete‐active‐space (CAS) SCF and spin‐unrestricted Kohn–Sham (UKS) calculations on potential surfaces, occupation numbers of natural orbitals, and correlation entropies. It was found that the UKS methods gave similar results to CASSCF, while the FON solutions appeared in only the nearly complete degenerate region. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem 93: 317–323, 2003
Density functional study of the conformers of Co4‐based single‐molecule magnet
Authors: Baruah Tunna , Pederson Mark R.
Published: April 2003

We present a detailed density functional theory‐based investigation on the geometry and electronic structure of the [Co4(hmp)4(MeOH)4Cl4] molecule. It is experimentally found to behave as a molecular magnet. The all‐electron electronic structure calculations and geometry optimization of the 88‐atom molecule were carried out within the generalized gradient approximation to the exchange correlation energy. We also study the electronic structures and geometries of a few low‐lying conformers of this molecule. It is found that the magnetic anisotropy energy is highly sensitive to the geometric structure of the molecule. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem 93: 324–331, 2003
Metal–insulator transition in the Hubbard model on a triangular lattice with disorders: Renormalization group approach
Authors: Wang J. X. , Kais Sabre
Published: April 2003

A multistages block renormalization group approach to study the metal–insulator transition in the Hubbard model on a triangular lattice with hexagonal blocks is presented and implemented. A second‐order phase transition with a critical point at U/t = 12.5 is obtained (the coupling parameters U and t correspond to the repulsive charging energy and to the nearest‐neighbor exchange coupling terms, respectively). In the presence of disorder the phase diagram for the system exhibits a metallic phase, an insulating phase, and a domain‐localized phase that separates them in the Mott regime. The subtle influence of electron–electron interactions upon inverse participation rate in the Anderson regime is also investigated. The results are discussed in light of experimental evidence for arrays of metalic quantum dots and exact numerical diagonalization of the Hubbard Hamiltonian. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem 93: 360–374, 2003
Pointed-end capping by tropomodulin3 negatively regulates endothelial cell motility
Authors: Fischer Robert S. , Fritz-Six Kimberly L. , Fowler Velia M.
Published: April 2003

Actin filament pointed-end dynamics are thought to play a critical role in cell motility, yet regulation of this process remains poorly understood. We describe here a previously uncharacterized tropomodulin (Tmod) isoform, Tmod3, which is widely expressed in human tissues and is present in human microvascular endothelial cells (HMEC-1). Tmod3 is present in sufficient quantity to cap pointed ends of actin filaments, localizes to actin filament structures in HMEC-1 cells, and appears enriched in leading edge ruffles and lamellipodia. Transient overexpression of GFP–Tmod3 leads to a depolarized cell morphology and decreased cell motility. A fivefold increase in Tmod3 results in an equivalent decrease in free pointed ends in the cells. Unexpectedly, a decrease in the relative amounts of F-actin, free barbed ends, and actin-related protein 2/3 (Arp2/3) complex in lamellipodia are also observed. Conversely, decreased expression of Tmod3 by RNA interference leads to faster average cell migration, along with increases in free pointed and barbed ends in lamellipodial actin filaments. These data collectively demonstrate that capping of actin filament pointed ends by Tmod3 inhibits cell migration and reveal a novel control mechanism for regulation of actin filaments in lamellipodia.
Stu2p, the budding yeast member of the conserved Dis1/XMAP215 family of microtubule-associated proteins is a plus end–binding microtubule destabilizer
Authors: van Breugel Mark , Drechsel David , Hyman Anthony
Published: April 2003

The Dis1/XMAP215 family of microtubule-associated proteins conserved from yeast to mammals is essential for cell division. XMAP215, the Xenopus member of this family, has been shown to stabilize microtubules in vitro, but other members of this family have not been biochemically characterized. Here we investigate the properties of the Saccharomyces cerevisiae homologue Stu2p in vitro. Surprisingly, Stu2p is a microtubule destabilizer that binds preferentially to microtubule plus ends. Quantitative analysis of microtubule dynamics suggests that Stu2p induces microtubule catastrophes by sterically interfering with tubulin addition to microtubule ends. These results reveal both a new biochemical activity for a Dis1/XMAP215 family member and a novel mechanism for microtubule destabilization.
Activation and Desensitization of the Recombinant P2X1 Receptor at Nanomolar ATP Concentrations
Authors: Rettinger Jürgen , Schmalzing Günther
Published: April 2003

Activation and desensitization kinetics of the rat P2X1 receptor at nanomolar ATP concentrations were studied in Xenopus oocytes using two-electrode voltage-clamp recording. The solution exchange system used allowed complete and reproducible solution exchange in <0.5 s. Sustained exposure to 1–100 nM ATP led to a profound desensitization of P2X1 receptors. At steady-state, desensitization could be described by the Hill equation with a K1/2 value of 3.2 ± 0.1 nM. Also, the ATP dependence of peak currents could be described by a Hill equation with an EC50 value of 0.7 μM. Accordingly, ATP dose-effect relationships of activation and desensitization practically do not overlap. Recovery from desensitization could be described by a monoexponential function with the time-constant τ = 11.6 ±1.0 min. Current transients at 10–100 nM ATP, which elicited 0.1–8.5% of the maximum response, were compatible with a linear three-state model, C-O-D (closed-open-desensitized), with an ATP concentration-dependent activation rate and an ATP concentration-independent (constant) desensitization rate. In the range of 18–300 nM ATP, the total areas under the elicited current transients were equal, suggesting that P2X1 receptor desensitization occurs exclusively via the open conformation. Hence, our results are compatible with a model, according to which P2X1 receptor activation and desensitization follow the same reaction pathway, i.e., without significant C to D transition. We assume that the K1/2 of 3.2 nM for receptor desensitization reflects the nanomolar ATP affinity of the receptor found by others in agonist binding experiments. The high EC50 value of 0.7 μM for receptor activation is a consequence of fast desensitization combined with nonsteady-state conditions during recording of peak currents, which are the basis of the dose-response curve. Our results imply that nanomolar extracellular ATP concentrations can obscure P2X1 receptor responses by driving a significant fraction of the receptor pool into a long-lasting refractory closed state.
The study of relative dynamics for spacecraft formation flying in eccentric orbits
Authors: Wang Pengji , Yang Di
Published: April 2003

Spacecraft formation flying is a key technology for future astronautics. The relative dynamics of formation flying in eccentric orbits is studied, and the relative motion between spacecrafts is analyzed in this paper. Based on the two‐body problem, the extension of Hill equations is achieved and used in relative dynamics of eccentric orbits. Moreover, the transformation of differential variables is applied, and the algebraic solution of the relative motion is obtained, which can be generally used for spacecraft formation flying in eccentric orbits. In addition, the analysis and numerical simulations are given for the relative motion of spacecraft formation flying. The results demonstrate that each spacecraft in eccentric orbits can run in a periodic motion surrounding the master spacecraft under some conditions. And multiple spacecraft can also set up some special formations according to missions.
Creating intellectual capital: a Habermasian community of practice (CoP) introduction
Authors: O’Donnell David , Porter Gayle , McGuire David , Garavan Thomas N. , Heffernan Margaret , Cleary Peter
Published: April 2003

John Seely Brown notes that context must be added to data and information to produce meaning. To move forward, Brown suggests, we must not merely look ahead but we must also learn to “look around” because learning occurs when members of a community of practice (CoP) socially construct and share their understanding of some text, issue or event. We draw explicitly here on the structural components of a Habermasian lifeworld in order to identify some dynamic processes through which a specific intellectual capital creating context, CoP, may be theoretically positioned. Rejecting the individualistic “Cogito, ergo sum” of the Cartesians, we move in line with Brown’s “we participate, therefore we are” to arrive within a Habermasian community of practice: we communicate, ergo, we create.
Increasing team emotional intelligence through process
Authors: Moriarty Patricia , Buckley Finian
Published: April 2003

The use of teams in the workplace is an accepted facet of current working life. Training is undertaken with a view to equipping students for the eventual transition to a workplace which demands the social scientific skills of being an active, contributing, co‐operative team member. The use of content and process in a practical‐based learning situation is the focus of this study, which assesses a range of learning approaches used to acquire a knowledge of the skills required for team working. The division of the course into content and task‐related aspects on the one hand, and process and subjective experience on the other, is evaluated from the point of view of the skills it transfers to the course participant. The concept of emotional intelligence is measured to ensure the practical application of theory on team working to the experience of team functioning. The results indicate the success of this approach and demonstrate its ease of transfer to the workplace training environment.
Mentoring in undergraduate business management programmes
Authors: Stewart Jim , Knowles Vanessa
Published: April 2003

This paper provides an overview of the role and contribution of mentoring in the context of a degree programme in which students spend their second and third years in‐company. As well as describing the process within the context of the degree, the paper examines the particular mentoring design features. Of specific interest is the shared mentoring role of academic members of staff and in‐company managers, and the variety of roles adopted by each of them, including coacher, facilitator, networker, counsellor. In addition, the mentors share a role in assessing students’ work in relation to their skills development, focusing on transferable skills, namely: communication, teamworking, adaptability and leadership. This paper draws upon findings of primary research conducted with the mentoring teams that exist within the wide range of consortium companies that sponsor the second and third years of the degree programme and Nottingham Business School. The paper reports the perceived benefits of such a mentoring process for academic and practitioners working in partnership to support and enhance the students’ learning experience.
Internal marketing of attitudes in Caribbean tourism
Authors: Crick Anne P.
Published: April 2003

Tourism is the mainstay of the Caribbean and the attitude of the people in the region may have a significant impact on the success of the industry. This paper analyzes the way in which tourism authorities of three Caribbean destinations have internally marketed tourism to their host populations in order to encourage the desired attitudinal expressions. A matrix of five possible responses to tourism was developed and each of the three countries was found to occupy different positions in the matrix. An analysis of the internal marketing strategies determined that the countries adopted different approaches based on their particular challenges but none of the approaches had achieved lasting success. The study concludes with recommendations for future research.
International hotel managers and key Caribbean challenges
Authors: Jayawardena Chandana , Haywood K. Michael
Published: April 2003

Broadly categorises hotel managers. Uses lessons learnt by managing hotels in the Caribbean. Presents two recent models in the context of the Caribbean. States that clear awareness of the “ABC” related to the host community is a key step in public relations. Presents the ideal attributes and prerequisites for success in international hotel management in a nutshell. Categorises Caribbean countries based on the ethnic mix and historic reasons for negative attitude towards tourism. Expresses views on key challenges that expatriate hotel managers face in the Caribbean. In conclusion, makes brief recommendations to international hotel managers planning to work in the Caribbean.
“Focus groups in cyberspace”: using the Internet for qualitative research
Authors: O’Connor Henrietta , Madge Clare
Published: April 2003

The potential of the Internet as a valuable methodological research tool is increasingly being recognised by both market researchers and academics. This paper contributes to the debate surrounding virtual synchronous group interviews and the value of online research. Specifically it introduces the use of a software conferencing technique – Hotline Connect – and discusses the implications of using the technique for Internet‐based research. In particular, issues of interview design, developing rapport and the virtual venue are considered. The paper draws on the experience of a recent research project entitled “cyberparents” and concludes that the use of conferencing software holds great potential for synchronous online interviewing. However, this must be combined with sensitive, ethical handling of both the research process and the data to overcome problems inherent in any interviewing situation.
African Swine Fever Virus Proteinase Is Essential for Core Maturation and Infectivity
Authors: Alejo Alí , Andrés Germán , Salas María L.
Published: April 2003

African swine fever virus (ASFV) encodes two polyprotein precursors named pp220 and pp62 that are sequentially processed during viral infection, giving rise to six major structural proteins. These reside at the core shell, a matrix domain located between the endoplasmic reticulum-derived inner envelope and the DNA-containing nucleoid. Proteolytic processing of the polyprotein precursors is catalyzed by the viral proteinase pS273R, a cysteine proteinase that shares sequence similarity with the SUMO1-processing peptidases. We describe here the construction and characterization of an ASFV recombinant, vS273Ri, that inducibly expresses the ASFV proteinase. Using vS273Ri, we show that repression of proteinase expression inhibits polyprotein processing and strongly impairs infective virus production. Electron microscopic examination of vS273Ri-infected cells showed that inhibition of proteolytic processing leads to the assembly of defective icosahedral particles containing a noncentered electron-dense nucleoid surrounded by an abnormal core shell of irregular thickness. The analysis of purified extracellular defective particles revealed that they contain the unprocessed pp220 and pp62 precursors, as well as the major DNA-binding nucleoid proteins p10 and pA104R. Altogether, these results indicate that the proteolytic processing of the polyproteins is not required for their incorporation into the assembling particles nor for the incorporation of the DNA-containing nucleoid. Instead, the ASFV proteinase is involved in a late maturational step that is essential for proper core assembly and infectivity.
Kaposi's Sarcoma-Associated Herpesvirus Lytic Origin (
ori-Lyt
)-Dependent DNA Replication: Identification of the
ori-Lyt
and Association of K8 bZip Protein with the Origin
Authors: Lin Cui Li , Li Hong , Wang Yan , Zhu Fan Xiu , Kudchodkar Sagar , Yuan Yan
Published: April 2003

Herpesviruses utilize different origins of replication during lytic versus latent infection. Latent DNA replication depends on host cellular DNA replication machinery, whereas lytic cycle DNA replication requires virally encoded replication proteins. In lytic DNA replication, the lytic origin (
ori-Lyt
) is bound by a virus-specified origin binding protein (OBP) that recruits the core replication machinery. In this report, we demonstrated that DNA sequences in two noncoding regions of the Kaposi's sarcoma-associated herpesvirus (KSHV) genome, between open reading frames (ORFs) K4.2 and K5 and between K12 and ORF71, are able to serve as origins for lytic cycle-specific DNA replication. The two
ori-Lyt
domains share an almost identical 1,153-bp sequence and a 600-bp downstream GC-rich repeat sequence, and the 1.7-kb DNA sequences are sufficient to act as a
cis
signal for replication. We also showed that an AT-palindromic sequence in the
ori-Lyt
domain is essential for the DNA replication. In addition, a virally encoded bZip protein, namely K8, was found to bind to a DNA sequence within the
ori-Lyt
by using a DNA binding site selection assay. The binding of K8 to this region was confirmed in cells by using a chromatin immunoprecipitation method. Further analysis revealed that K8 binds to an extended region, and the entire region is 100% conserved between two KSHV
ori-Lyt
's. K8 protein displays significant similarity to the Zta protein of Epstein-Barr virus (EBV), which is a known OBP of EBV. This notion, together with the ability of K8 to bind to the KSHV
ori-Lyt
, suggests that K8 may function as an OBP in KSHV.