bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of filler–rubber interactions on the viscoelastic properties of carbon‐black‐filled rubber compounds
Authors: Léopoldès J. , Barrès C. , Leblanc J. L. , Georget P. 
Published: November 2003

AbstractThe specific role of filler–rubber interactions in dynamic properties was investigated. Natural rubber compounds, filled with N330 carbon black, were used, and the filler surface was modified through a gas treatment in the solid phase. The effects of this filler surface treatment on the dynamic properties were systematically studied at equal filler dispersion levels. The dynamic properties were assessed for both uncured and vulcanized compounds, and a number of advanced investigative techniques were used to characterize not only the modification of the carbon particle surface by an oxidative treatment but also the structure of the filled rubber compounds. Particular attention was paid to techniques that gave access to the segmental mobility to explain the benefit observed with modified carbon black. A molecular interpretation, based on NMR measurements, was considered that took into account physicochemical parameters. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 577–588, 2004
Properties of high‐density polyethylene filled with waste crosslinked foam
Authors: Tamboli S. M. , Mhaske S. T. , Kale D. D. 
Published: November 2003

AbstractCrosslinked polyethylene foam is widely used in packaging and as an insulation material. Finely ground waste of such crosslinked foam mesh size 7 or particle size less than 2815 μm is used as a filler in high‐density polyethylene (HDPE) of two different grades (7.5 and 21 MFI). Mechanical, thermal, and morphological properties of filled composites is studied experimentally. Waste foam powder concentration was varied up to 40% by weight basis. Impact strength of base HDPE increased by a factor of six. The overall changes in mechanical properties are similar to the crosslinking effect. It is believed that waste foam particles act as a point of entanglement with different chains of polyethylene. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 110–114, 2004
Structure–property relation in polyvinyl alcohol/starch composites
Authors: Siddaramaiah  , Raj Baldev , Somashekar R. 
Published: November 2003

AbstractA series of polyvinyl alcohol (PVA)/starch films were cast by the solvent method. Mechanical, optical, wide‐angle X‐ray scattering (WAXS), and biodegradation studies of starch‐filled PVA films were carried out. With the addition of starch there was an increase in haze and diffusion of light, whereas there was only slight change associated with tensile behavior and burst strength of the PVA film. Microstructural parameters, such as crystal size (〈N〉) and lattice distortion (g, in %) were estimated using one‐dimensional Hosemann's paracrystalline model along with WAXS data. These parameters quantify the changes in the PVA/starch systems, which resulted in the observed physical properties. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 12: 630–635, 2004
Immobilization of glucose oxidase in chitosan gel beads
Authors: Ghanem Amyl , Ghaly Ahmed 
Published: November 2003

AbstractGlucose oxidase was conjugated to the biopolymer chitosan using carbodiimide conjugation. Gel beads were formed from the enzyme–biopolymer complex, and the activity of the immobilized enzyme was compared to the method of encapsulating the enzyme in chitosan. The activity of the immobilized enzyme was found to increase with increasing carbodiimide concentration and time of incubation, to a maximum. Enzyme activity decreased with time as the beads were air‐dried. The pH optima of the immobilized enzyme was shifted to a more acidic value compared to that of the free enzyme. The use of carbodiimide chemistry to conjugate glucose oxidase to a chitosan gel was demonstrated. This technique holds promise for the development of immobilized enzymes for applications in medicine, biosensors, and bioprocessing. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 861–866, 2004
The synthesis and characterization of poly(ethylene glycol) grafted on pullulan
Authors: Jiao Yonghua , Fu Yu , Jiang Zhenhua 
Published: November 2003

AbstractThe pullulans grafted with poly(ethylene glycol) with different degrees of substitution (DS: 0.02–0.2) are synthesized by reaction of pullulan and poly(ethylene glycol) terminated with carboxylic acid. The structure of the resulting modified pullulans is characterized with 1H‐NMR and FTIR spectra. The DS of the products increase with the amount of the poly(ethylene glycol) added. The appearances of the products change considerably and the solubility in organic solvent is enhanced visibly. It was found that pullulan derivative is biodegradable. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1217–1221, 2004
Volume strain measurements on CACO3/polypropylene particulate composites: The effect of particle size
Authors: Lazzeri A. , Thio Y. S. , Cohen R. E. 
Published: November 2003

AbstractThe use of rigid fillers to toughen polymers has received considerable attention in recent years. The role of the rigid particle here is that of debonding, at some stage, from the matrix, thus triggering dilatational processes similar to those observed in rubber‐toughened polymers. The role of particle size in these rigid filled composites has not been studied in great detail. In this work, volume strain measurements were carried out on a series of particulate composites based on polypropylene filled with calcium carbonate (CC) particles with average diameters of 0.07, 0.7, and 3.5 μm and filler volume fractions ranging from 0.05 to 0.30. The experimental results have shown a strong particle size effect. A model is proposed to take this effect into account, based upon the formation of an immobilized layer of polymer on the surface of the filler particles. The experimental results are consistent with a surface layer of 15–25 nm. The results are discussed in relation to the fracture behavior of these composites reported earlier. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 925–935, 2004
Preparation and characterization of PET/silica nanocomposites
Authors: Liu Wentao , Tian Xingyou , Cui Ping , Li Yong , Zheng Kang , Yang Ye 
Published: November 2003

AbstractPoly(ethylene terephthalate) (PET)/silica nanocomposites were fabricated by direct polymerizing PET monomer dispersed with organic modified silica nanoparticles. The characteristics and properties of these nanocomposites were investigated by the transmission electron microscopy, differential scanning calorimetry, and thermogravimetric analysis, respectively. The results show that (1) the nanoparticles have been well dispersed in the polymer matrix; (2) the addition of nanoparticles can speed up the crystallization and melting point; and (3) the addition has no significant effect on the synthesis process. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1229–1232, 2004
Thermal behavior and properties of polystyrene/poly(methyl methacrylate) blends
Authors: Chuai Chengzhi , Almdal Kristoffer , Lyngaae‐Jørgensen Jørgen 
Published: November 2003

AbstractThe thermal behavior and properties of immiscible blends of polystyrene (PS) and poly(methyl methacrylate) (PMMA) with and without PS‐b‐PMMA diblock copolymer at different melt blending times were investigated by use of a differential scanning calorimeter. The weight fraction of PS in the blends ranged from 0.1 to 0.9. From the measured glass transition temperature (Tg) and specific heat increment (ΔCp) at the Tg, the PMMA appeared to dissolve more in the PS phase than did the PS in the PMMA phase. The addition of a PS‐b‐PMMA diblock copolymer in the PS/PMMA blends slightly promoted the solubility of the PMMA in the PS and increased the interfacial adhesion between PS and PMMA phases during processing. The thermogravimetric analysis (TGA) showed that the presence of the PS‐b‐PMMA diblock copolymer in the PS/PMMA blends afforded protection against thermal degradation and improved their thermal stability. Also, it was found that the PS was more stable against thermal degradation than that of the PMMA over the entire heating range. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 609–620, 2004
Nonisothermal melt crystallization kinetics of poly(ethylene terephthalate)/clay nanocomposites
Authors: Wang Yaming , Shen Changyu , Li Haimei , Li Qian , Chen Jingbo 
Published: November 2003

AbstractVarious kinetic models, namely, the Avrami analysis modified by Jeziorny, the Ozawa model, and a method developed by Mo, were applied to describe the nonisothermal melt crystallization process of poly(ethylene terephthalate) (PET) and two PET/clay nanocomposites of different viscosities. The Avrami analysis modified by Jeziorny could gratifyingly describe the primary nonisothermal crystallization stage of PET and two PET/clay nanocomposites. The difference in the values of the Avrami exponent between PET and PET/clay nanocomposites suggested that the nonisothermal crystallization of PET/clay nanocomposites corresponds to a tridimensional growth with heterogeneous nucleation. The values of half‐time showed that the crystallization rate of PET/clay nanocomposites is faster than that of PET at a given cooling rate. The Ozawa analysis failed to provide an adequate description of the nonisothermal crystallization of PET/clay nanocomposites. The method developed by Mo was successful in describing the nonisothermal crystallization of pristine PET and PET/clay nanocomposites. The activation energy for nonisothermal crystallization of pristine PET and two PET/clay nanocomposites of different viscosities, based on the Augis–Bennett method, the Kissinger method, and the Takhor method, respectively, were evaluated, and it was concluded that the absolute value of activation energy for PET is lower than that of PET/clay nanocomposites, and this showed that introduction of clay into PET matrix weakens the dependence of the nonisothermal crystallization exotherms peak temperatures on the cooling rates used. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 308–314, 2004
Surgical treatment of hydatid cysts of the liver
Authors: Aǧaoǧlu (N. A. Mustafa) N , Türkyılmaz S , Arslan M K 
Published: November 2003

Abstract

Background
Echinococcosis is a zoonotic disease that occurs throughout the world. The purpose of this study was to assess the clinical features and results of surgical treatment of hepatic hydatid cysts.

Methods
One hundred and two patients operated on between 1991 and 2002 were reviewed retrospectively. The patients' demographic data, location, number and size of cysts, type of surgical procedure performed, morbidity, recurrences and duration of hospital stay were recorded.

Results
There were 74 male and 28 female patients with ages ranging from 15 to over 60 years. The most frequent symptom was abdominal pain. From the total of 136 hepatic cysts, 54 (39·7 per cent) were managed by cystostomy and drainage, 40 (29·4 per cent) by cystostomy and capitonnage, 16 (11·8 per cent) by cystostomy and omentoplasty, 24 (17·6 per cent) by cystectomy and two (1·5 per cent) by left lateral hepatic resection. Postoperative complications were more frequent following cystostomy with omentoplasty (six of 16 patients) compared with cystectomy (none of 18) (P = 0·005). Choledochotomy increased the length of hospital stay in patients having cystostomy and drainage (P = 0·021) and in those having cystostomy with omentoplasty (P = 0·028). Two recurrences were observed.

Conclusion
Surgery combined with medical treatment by albendazole is effective in the eradication of hepatic hydatid disease and in the prevention of local recurrence.
Endovascular management of traumatic cervicothoracic arteriovenous fistula
Authors: du Toit D F , Leith J G , Strauss D C , Blaszczyk M , Odendaal J de V , Warren B L 
Published: November 2003

Abstract

Background
This study evaluated a single-centre experience with endovascular repair of traumatic arteriovenous fistula in the cervicothoracic region.

Methods
Endovascular repair of 27 traumatic cervicothoracic arteriovenous fistulas was attempted between August 1998 and December 2001. Patients with active bleeding or end-organ ischaemia were excluded. Follow-up was accomplished with clinical, duplex Doppler and arteriographic evaluation after 1 month and then every 3 months.

Results
Twelve patients with a major vessel injury were treated by stent-graft placement. Vessels involved were the subclavian (eight), common carotid (three) and internal carotid (one) arteries. Subclavian artery side branches were embolized in three of the eight patients. Four patients developed early type 4 endoleaks but all resolved. Treatment with stent-grafts was ultimately successful in all 12 patients. Three patients were lost to follow-up. During mean follow-up of 21 (range 3–36) months, one of the remaining patients developed a graft stenosis. Fifteen patients with minor vessel injuries were treated with arterial embolization. Vessels embolized were subclavian artery branches (four), external carotid artery and branches (seven) and vertebral arteries (four). Successful embolization was accomplished in ten of 15 patients.

Conclusion
Endovascular therapy is a promising alternative to surgery for selected patients with cervicothoracic arteriovenous fistula.
Cosmesis and satisfaction after breast-conserving surgery correlates with the percentage of breast volume excised
Authors: Cochrane R A , Valasiadou P , Wilson A R M , Al-Ghazal S K , Macmillan R D 
Published: November 2003

Abstract

Background
The cosmetic outcome after breast-conserving surgery correlates with psychosocial adjustment. Previous studies have shown that, among other factors, cosmesis is dependent on breast size and weight of the wide local excision specimen. This study assessed cosmetic outcome relative to a combination of these factors—the estimated percentage of breast volume excised (EPBVE).

Methods
The study group consisted of 151 women who had undergone breast-conserving surgery. All had previously completed a patient satisfaction questionnaire and an independent panel had assessed cosmetic outcome. Their mammograms were reviewed and breast volume was estimated. A validation series showed cone volume on the oblique mammogram to predict true breast weight most accurately (r = 0·93).

Results
Both subjective cosmetic assessment and patient satisfaction correlated strongly with EPBVE. Overall, when the EPBVE was below 10 per cent, 83·5 per cent of patients were very satisfied with their appearance and only 3·1 per cent were not satisfied, compared with 37·0 and 16·7 per cent respectively if the EPBVE was more than 10 per cent. However, tumour location in the breast was also an important factor; cosmetic outcome was worse for medial tumours.

Conclusion
The percentage of breast volume excised was an important determinant of cosmesis and patient satisfaction after breast-conserving surgery. Calculating the EPBVE before surgery may help select women in whom breast reshaping or volume replacement should be considered.
Predictors of improvement in health-related quality of life in patients undergoing cholecystectomy
Authors: Quintana J M , Aróstegui I , Cabriada J , López de Tejada I , Perdigo L 
Published: November 2003

AbstractBackgroundFew studies have assessed health-related quality of life (HRQoL) among patients undergoing cholecystectomy. This study aimed to determine clinical variables that predict changes in HRQoL following cholecystectomy.MethodsThis was a prospective study of consecutive patients undergoing elective cholecystectomy for gallstones in six hospitals. Patients were asked to complete two questionnaires—the Short Form 36 (SF-36) and the Gastrointestinal Quality of Life Index (GIQLI)—before and 3 months after cholecystectomy. Multivariate linear regression models were used to examine factors potentially contributing to changes in HRQoL.ResultsPatients with symptomatic cholelithiasis and low surgical risk experienced the highest HRQoL gains in several SF-36 and GIQLI domains, with significant improvements in physical function detected by both instruments, compared with asymptomatic individuals at high surgical risk. Patients with asymptomatic cholelithiasis or high surgical risk experienced least improvement.ConclusionThese data indicate that cholecystectomy is appropriate for patients with symptomatic cholelithiasis and low surgical risk. In terms of HRQoL, the risk to benefit ratio seems poor for patients with asymptomatic gallstones.
Randomized clinical trial of Ligasure™ versus conventional surgery for extended gastric cancer resection
Authors: Lee W-J , Chen T-C , Lai I-R , Wang W , Huang M-T 
Published: November 2003

Abstract

Background
The Ligasure™ Vessel Sealing System is a haemostatic device designed primarily for use in abdominal surgery. Randomized trials have demonstrated that it is safe and quick for haemorrhoidectomy, but there is no evidence that it confers any advantage in complicated gastrointestinal surgery. The aim of the present study was to examine the value of the Ligasure™ system in extended lymph node dissection (D2) during gastrectomy for cancer in a randomized clinical trial.

Methods
D2 gastric resection performed with the Ligasure™ system was compared with resection using conventional haemostatic methods in a prospective randomized trial. Central randomization (40 patients in each group) was performed after a staging laparotomy. The main outcome measures were operating time, intraoperative blood loss, postoperative course and complications.

Results
Ligasure™ was associated with less intraoperative blood loss (mean(s.d.) 142(73) versus 239(124) ml; P = 0·001) and a shorter operating time (mean(s.d.) 169(25) versus 222(28) min; P = 0·001) than conventional operation. Postoperative drainage fluid volumes were greater in the Ligasure™ group (mean(s.d.) 1577(940) versus 886(542) ml; P = 0·020). There were no differences in postoperative complications or hospital stay.

Conclusion
The Ligasure™ Vessel Sealing System is safe for use in extended lymph node dissection for gastric cancer, and is associated with a shorter operating time and decreased blood loss compared with conventional haemostatic techniques.
Centrifugal visual system of Crocodylus niloticus: A hodological, histochemical, and immunocytochemical study
Authors: Médina Monique , Repérant Jacques , Ward Roger , Miceli Dom 
Published: November 2003

AbstractThe retinopetal neurons of Crocodylus niloticus were visualized by retrograde transport of rhodamine beta‐isothiocyanate or Fast Blue administered by intraocular injection. Approximately 6,000 in number, these neurons are distributed in seven regions extending from the mesencephalic tegmentum to the rostral rhombencephalon, approximately 70% being located contralaterally to the injected eye. None of the centrifugal neurons projects to both retinae. The retinopetal neurons are located in rostrocaudal sequence in seven regions: the formatio reticularis lateralis mesencephali, the substantia nigra, the griseum centralis tectalis, the nucleus subcoeruleus dorsalis, the nucleus isthmi parvocellularis, the locus coeruleus, and the commissura nervi trochlearis. The greatest number of cells (approximately 93%) is found in the nucleus subcoeruleus dorsalis. The majority are multipolar or bipolar in shape and resemble the ectopic centrifugal visual neurons of birds, although a small number of monopolar neurons resembling those of the avian isthmo‐optic nucleus may also be observed. A few retinopetal neurons in the griseum centralis tectalis were tyrosine hydroxylase (TH) immunoreactive. Moreover, in the nuclei subcoeruleus dorsalis and isthmi parvocellularis, both ipsilaterally and contralaterally, approximately one retinopetal neuron in three (35%) was immunoreactive to nitric oxide synthase (NOS), and a slightly higher proportion (38%) of retinopetal neurons were immunoreactive for choline acetyltransferase (ChAT). Some of them contained colocalized ChAT and NOS/reduced nicotinamide adenine dinucleotide phosphate–diaphorase. Fibers immunoreactive to TH, serotonin (5‐HT), neuropeptide Y (NPY), or Phe‐Met‐Arg‐Phe‐amide (FMRF‐amide) were frequently observed to make intimate contact with rhodamine‐labeled retinopetal neurons. These findings are discussed in relation to previous results obtained in other reptilian species and in birds. J. Comp. Neurol. 468:65–85, 2004. © 2003 Wiley‐Liss, Inc.
Voronoi deformation density (VDD) charges: Assessment of the Mulliken, Bader, Hirshfeld, Weinhold, and VDD methods for charge analysis
Authors: Fonseca Guerra Célia , Handgraaf Jan‐Willem , Baerends Evert Jan , Bickelhaupt F. Matthias 
Published: November 2003

AbstractWe present the Voronoi Deformation Density (VDD) method for computing atomic charges. The VDD method does not explicitly use the basis functions but calculates the amount of electronic density that flows to or from a certain atom due to bond formation by spatial integration of the deformation density over the atomic Voronoi cell. We compare our method to the well‐known Mulliken, Hirshfeld, Bader, and Weinhold [Natural Population Analysis (NPA)] charges for a variety of biological, organic, and inorganic molecules. The Mulliken charges are (again) shown to be useless due to heavy basis set dependency, and the Bader charges (and often also the NPA charges) are not realistic, yielding too extreme values that suggest much ionic character even in the case of covalent bonds. The Hirshfeld and VDD charges, which prove to be numerically very similar, are to be recommended because they yield chemically meaningful charges. We stress the need to use spatial integration over an atomic domain to get rid of basis set dependency, and the need to integrate the deformation density in order to obtain a realistic picture of the charge rearrangement upon bonding. An asset of the VDD charges is the transparency of the approach owing to the simple geometric partitioning of space. The deformation density based charges prove to conform to chemical experience. © 2003 Wiley Periodicals, Inc. J Comput Chem 25: 189–210, 2004
Performance comparison of generalized born and Poisson methods in the calculation of electrostatic solvation energies for protein structures
Authors: Feig Michael , Onufriev Alexey , Lee Michael S. , Im Wonpil , Case David A. , Brooks Charles L. 
Published: November 2003

AbstractThis study compares generalized Born (GB) and Poisson (PB) methods for calculating electrostatic solvation energies of proteins. A large set of GB and PB implementations from our own laboratories as well as others is applied to a series of protein structure test sets for evaluating the performance of these methods. The test sets cover a significant range of native protein structures of varying size, fold topology, and amino acid composition as well as nonnative extended and misfolded structures that may be found during structure prediction and folding/unfolding studies. We find that the methods tested here span a wide range from highly accurate and computationally demanding PB‐based methods to somewhat less accurate but more affordable GB‐based approaches and a few fast, approximate PB solvers. Compared with PB solvation energies, the latest, most accurate GB implementations were found to achieve errors of 1% for relative solvation energies between different proteins and 0.4% between different conformations of the same protein. This compares to accurate PB solvers that produce results with deviations of less than 0.25% between each other for both native and nonnative structures. The performance of the best GB methods is discussed in more detail for the application for force field‐based minimizations or molecular dynamics simulations. © 2003 Wiley Periodicals, Inc. J Comput Chem 25: 265–284, 2004