bluuebunny/crossref_metadata_2025 huggingface dataset:
Applying the method of moments to the analysis of large tapered slot antennas through unequal sectioning
Authors: Mokraoui A. , Aksas R.
Published: January 2004

An attempt is made to apply the method of moments (MoM) to large tapered slot antennas (TSA). Previous analyses of the current distribution on the conducting plates and the polarization current in the dielectric region suggested the use of an optimal unequal sectioning of the antenna. That sectioning helps to reduce the number of involved unknowns while improving the modelling of the slot geometry. Our numerical results are compared to experimental measurements, and large TSA proved to be efficient with respect to other analysis methods. Despite the amount of hardware resources used by this model, our algorithm is run on a desktop computer. Once again, the MoM shows its sharp accuracy in handling electromagnetic problems. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 40: 331–335, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11371
Electromagnetic analysis techniques for 3D microwave structures using commercial electromagnetic software
Authors: Tsitsos S. , Gibson A. A. P. , Davis L. E.
Published: January 2004

A three‐pole ceramic monoblock filter is analysed using HFSS. The numerical results are compared with the measurements, and possible reasons for disagreement between the measured and simulated results are investigated. The development of new techniques to minimise this discrepancy is also presented. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 40: 335–339, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11372
Radar pulse interleaving for multi‐target tracking
Authors: Elshafei Moustafa , Sherali Hanif D. , Smith J. Cole
Published: January 2004

In a multifunction radar, the maximum number of targets that can be managed or tracked is an important performance measure. Interleaving algorithms developed to operate radars exploit the dead‐times between the transmitted and the received pulses to allocate new tracking tasks that might involve transmitting or receiving pulses, thus increasing the capacity of the system. The problem of interleaving N targets involves a search among N! possibilities, and suboptimal solutions are usually employed to satisfy the real‐time constraints of the radar system. In this paper, we present new tight 0–1 integer programming models for the radar pulse interleaving problem and develop effective solution methods based on Lagrangian relaxation techniques. © 2003 Wiley Periodicals, Inc. Naval Research Logistics, 2004.
Analysis of algorithms for two‐stage flowshops with multi‐processor task flexibility
Authors: Vairaktarakis George L. , Lee Chung‐Yee
Published: January 2004

In this article we introduce a 2‐machine flowshop with processing flexibility. Two processing modes are available for each task: namely, processing by the designated processor, and processing simultaneously by both processors. The objective studied is makespan minimization. This production environment is encountered in repetitive manufacturing shops equipped with processors that have the flexibility to execute orders either individually or in coordination. In the latter case, the product designer exploits processing synergies between two processors so as to execute a particular task much faster than a dedicated processor. This type of flowshop environment is also encountered in labor‐intensive assembly lines where products moving downstream can be processed either in the designated assembly stations or by pulling together the work teams of adjacent stations. This scheduling problem requires determining the mode of operation of each task, and the subsequent scheduling that preserves the flowshop constraints. We show that the problem is ordinary NP‐complete and obtain an optimal solution using a dynamic programming algorithm with considerable computational requirements for medium and large problems. Then, we present a number of dynamic programming relaxations and analyze their worst‐case error performance. Finally, we present a polynomial time heuristic with worst‐case error performance comparable to that of the dynamic programming relaxations. © 2003 Wiley Periodicals, Inc. Naval Research Logistics, 2004.
Economic ordering decisions with market choice flexibility
Authors: Geunes Joseph , Shen Zuo‐Jun , Romeijn H. Edwin
Published: January 2004

Standard approaches to classical inventory control problems treat satisfying a predefined demand level as a constraint. In many practical contexts, however, total demand is comprised of separate demands from different markets or customers. It is not always clear that constraining a producer to satisfy all markets is an optimal approach. Since the inventory‐related cost of an item depends on total demand volume, no clear method exists for determining a market's profitability a priori, based simply on per unit revenue and cost. Moreover, capacity constraints often limit a producer's ability to meet all demands. This paper presents models to address economic ordering decisions when a producer can choose whether to satisfy multiple markets. These models result in a set of nonlinear binary integer programming problems that, in the uncapacitated case, lend themselves to efficient solution due to their special structure. The capacitated versions can be cast as nonlinear knapsack problems, for which we propose a heuristic solution approach that is asymptotically optimal in the number of markets. The models generalize the classical EOQ and EPQ problems and lead to interesting optimization problems with intuitively appealing solution properties and interesting implications for inventory and pricing management. © 2003 Wiley Periodicals, Inc. Naval Research Logistics, 2004.
Epidemiologic analysis of 1,442 children and adolescents registered in the German germ cell tumor protocols
Authors: Schneider Dominik T. , Calaminus Gabriele , Koch Susanne , Teske Carmen , Schmidt Piroska , Haas Rainer J. , Harms Dieter , Göbel Ulrich
Published: January 2004

Background

Germ cell tumors (GCTs) constitute a heterogeneous group of tumors that significantly vary with respect to their clinical presentation and biology. The objective of this analysis was to analyze a large population‐based pediatric cohort of GCTs and to evaluate the parameters age, sex, site of the tumor, histology, and potential correlations between these parameters.

Procedure

Between 1981 and 2000, 1,442 patients were prospectively enrolled onto the German protocols for testicular and non‐testicular GCTs. Tumors were histologically classified according to the WHO.

Results

We observed a bimodal age distribution with a first peak during infancy and a second after the onset of puberty. At birth, almost all tumors were teratomas, sometimes with microfoci of yolk sac tumor, which on the other hand, was the predominant histology during childhood. After the onset of puberty, germinomatous GCTs represented the most frequent histological subtype, and malignant non‐germinomatous GCTs often presented as mixed tumors with choriocarcinoma and embryonal carcinoma components. During infancy, non‐gonadal GCTs accounted for the majority of GCTs, while after the onset of puberty, gonadal GCTs predominated. Notably, among non‐gonadal GCTs, there was a female predominance during childhood and a strong male predominance during adolescence.

Conclusions

Two separate groups of GCTs with distinct clinical features relevant for differential diagnosis and the diagnostic assessment can be distinguished. This observation correlates with genetic studies that reveal different genetic changes in childhood and adolescence GCTs. Further studies are needed to elucidate the molecular mechanisms of germ cell and GCT development that account for the age‐ and sex‐dependent clinical manifestation. © 2003 Wiley‐Liss, Inc.
Significance of pleural effusion at diagnosis of Wilms tumor
Authors: Corey Bethany , Yang Chen‐Ho , Wilimas Judith A. , Davidoff Andrew , Dome Jeffrey S.
Published: January 2004

Background

Pleural effusion is uncommon at diagnosis of Wilms tumor. Because the clinical significance of this finding has not been reported, a retrospective review of this entity was conducted.

Procedure

The radiology reports and medical records of 233 patients with Wilms tumor who were treated at St. Jude Children's Research Hospital between 1985 and 2001 were reviewed.

Results

Ten of the 233 patients (4.3%) had pleural effusions detected on pre‐nephrectomy imaging studies. Computed tomography (CT) scans were more sensitive than chest X‐rays in identifying pleural effusions. All of the patients with pleural effusions had tumors of favorable histology. Two patients had stage II disease, five had stage III disease, two had stage IV disease, and one had stage V (bilateral) disease. All of the effusions occurred on the same side as the primary kidney tumors and six effusions were associated with ascites. The two effusions that were tapped were negative for tumor cells. All 10 patients in our series were alive without recurrence with a median follow‐up duration of 68 months, yet only two patients were treated with lung irradiation.

Conclusion

Pleural effusion at presentation of Wilms tumor is uncommon and not associated with adverse prognosis. We recommend that pleural effusions be tapped whenever feasible if the results will change therapy. Patients with pleural effusions that are small and difficult to tap may be treated according to their local stage without pulmonary irradiation. Further analysis of pleural effusions in a larger group of patients is necessary to confirm our preliminary observations. © 2003 Wiley‐Liss, Inc.
Ex vivo drug resistance in childhood acute myeloid leukemia on relapse is not higher than at first diagnosis
Authors: Styczynski Jan , Wysocki Mariusz
Published: January 2004

Relapsed pediatric patients with acute myeloid leukemia (AML) have a poor clinical prognosis. The aim of this study was the analysis of the ex vivo drug resistance profile on relapse in childhood AML in comparison to newly diagnosed AML. The results of 98 pediatric AML samples tested by the MTT assay were analyzed. Eighteen samples (18%) were excluded from the further analysis due to spontaneous apoptosis of blasts in 4‐days culture, low percentage of myeloblasts in the sample either in the beginning or at the end of the assay, infection, or formation of clots in the sample. Finally, ex vivo drug resistance of 20 relapsed samples were compared with that of 60 de novo AML, including 9 matched pairs. Up to 18 drugs were tested for each patient. No significant differences between drug resistance at diagnosis and at relapse in AML was found, neither for the whole groups of patients, nor for matched pairs only. Possibly, relatively good sensitivity of myeloblasts on relapse was found against melphalan, thiotepa, 4‐HOO‐ifosfamide, and cladribine. In summary, cellular drug resistance in childhood AML at relapse is not higher than at first diagnosis. These observations suggest that other, than cellular drug resistance, factors play a key role in therapy failure of relapsed childhood AML. © 2003 Wiley‐Liss, Inc.
Is alveolar histotype a prognostic factor in paratesticular rhabdomyosarcoma? The experience of Italian and German Soft Tissue Sarcoma Cooperative Group
Authors: Ferrari Andrea , Bisogno G. , Casanova M. , Brecht I.B. , Alaggio R. , Cecchetto G. , Provenzi M. , Koscielniak E. , Treuner J. , Carli M.
Published: January 2004

Purpose

To ascertain whether alveolar histology retains its adverse prognostic role in the subset of paratesticular rhabdomyosarcoma (RMS) patients, generally characterized by a very good outcome.

Patients and Methods

Twenty pediatric patients were treated over a 25‐year period using the protocols of the Italian and German Soft Tissue Sarcoma Cooperative Groups. Clinical characteristics at presentation were much the same as in non‐alveolar patients.

Results

The proportion of patients with alveolar histotype (8%) in paratesticular site was lower than in the general RMS population (20–30%). With a median follow‐up of 122 months, 5‐year EFS and OS were 78 and 89%, respectively.

Conclusion

Our data suggest a distinctly better clinical behavior of paratesticular alveolar RMS than when the disease occurs at other sites. These patients were more intensively treated than the embryonal cases, however, so—although a treatment intensity reduction may be desiderable—the idea of eliminating the alkylating agents (as in low‐risk embryonal paratesticular RMS) must be considered with great caution. © 2003 Wiley‐Liss, Inc.
Long‐term follow‐up of survivors of childhood cancer in the UK
Authors: Taylor Aliki , Hawkins Mike , Griffiths Annie , Davies Helena , Douglas Carolyn , Jenney Meriel , Wallace W Hamish B , Levitt Gill
Published: January 2004

Background

Childhood cancer is rare, but there are now good survival prospects and in the UK approximately 1 in 1,000 young adults is a survivor of childhood cancer. There are many adverse health outcomes associated with the treatment of childhood cancer often arising several years after completion of treatment. The aim of this study was to quantify the long‐term clinical follow‐up practices concerning survivors of childhood cancer.

Procedure

A cross‐sectional postal survey of 22 treatment centres of the United Kingdom Children's Cancer Study Group (UKCCSG) clinicians was carried out as well as a cross‐sectional postal survey of general practitioners of most adult survivors of childhood cancer in Britain.

Results

Subsequent to 5 years after the end of treatment: 52% of UKCCSG clinicians follow‐up all survivors for life, while 45% discharge some patients. Of those clinicians discharging: over 50% discharged benign, stage I or tumors treated with surgery alone, in contrast 16% reported discharging all or most patients; almost all (97%) clinicians discharged to a general practitioner. Only 14% of clinicians reported nurses undertook a specialist role. Sixty‐five percent of the 10,979 general practitioners reported that their patient was not on regular hospital follow‐up.

Conclusions

There are wide variations in the extent to which survivors of childhood cancer are discharged from hospital follow‐up. There is a need for regularly updated national guidelines concerning the levels of follow‐up required for specific groups of survivors defined principally by the treatment they received. Pediatr Blood Cancer 2004;42:161–168. © 2003 Wiley‐Liss, Inc.
Synthesis of semifluorinated block copolymers by atom transfer radical polymerization
Authors: Radhakrishnan Karunakaran , Switek Karen A. , Hillmyer Marc A.
Published: January 2004

Two sets of styrene‐based semifluorinated block copolymers, one with a perfluoroether pendant group and another with a perfluoroalkyl group, were synthesized by atom transfer radical polymerization. Microphase separation of the block copolymers was established by small‐angle X‐ray scattering and differential scanning calorimetry (DSC). DSC measurements also showed that the perfluoroether‐based polymer had a low glass‐transition temperature (−44 °C). Contact‐angle measurements indicated that the semifluorinated block copolymers had low surface energies (ca. 13 mJ/m2). These materials hold promise as low‐surface‐energy additives or surfactants for supercritical CO2applications. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 853–861, 2004
A polymeric photobase generator containing oxime–urethane groups: Crosslinking reaction and application to negative photoresist
Authors: Chae Kyu Ho , Sung Kyung Hee
Published: January 2004

A polymeric photobase generator containing oxime–urethane groups was prepared by copolymerization of methyl methacrylate and methacryloxyethyl benzophenoneoxime urethane, and its photo and thermal crosslinking reaction after irradiation was examined from the measurement of UV and IR absorption spectral changes, insoluble fraction, and molecular weight changes. The photo‐crosslinking reaction of the copolymer film was more efficient when irradiations were carried out with 310 nm UV light in the presence of benzophenone than with 254 nm UV light without the addition of benzophenone. The crosslinking reaction increased after postexposure baking (PEB), and this thermal crosslinking reaction mechanism was studied from the identification of the photolysis products of a model compound, benzophenoneoxime phenylurethane, by a high‐performance liquid chromatography. The results indicate that the thermal crosslinking reaction of the copolymer after PEB is due to the formation of urea‐type chemical bonds. Resist properties of the copolymer were examined from the measurement of normalized thickness and micropattern development. A negative tone image with a resolution of 2 μm was obtained with this copolymer, having a sensitivity (D) of 1200 mJ/cm2 and contrast (γn) of 1.31, when irradiation was carried out with 310 nm UV light in the presence of benzophenone following chloroform development. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 975–984, 2004
Photoinitiated, inverse emulsion polymerization of acrylamide: Some mechanistic and kinetic aspects
Authors: Liu Lianying , Yang Wantai
Published: January 2004

The kinetics of photoinitiated, inverse emulsion polymerization of acrylamide with 2,2‐dimethoxy‐2‐phenylacetophenone (DMPA) as a photoinitiator was investigated under three different cases. First, in a quartz reactor transparent to full UV light, the polymerization rate (Rp) increased and then decreased with the change of initiator order from 0.27 to a negative value when the DMPA concentration was increased, and it was particularly unusual that monomer orders at different DMPA concentrations were lower than the first. Second, for polymerization without DMPA in a quartz reactor, the dependence of Rp on monomer concentration was similar to that of Rp on initiator concentration in the aforementioned case. Third, when polymerization was carried out in a Pyrex reactor where the far UV light was filtered, a peak rate was also observed, and initiator orders varied from 0.24 to a negative value; however, under this case monomer orders at different initiator concentrations were greater than the first. These results indicated that the effect of absorbance often observed in bulk or solution photopolymerization also existed in this system, and the self‐initiation of monomer had some influence on polymerization, and the role of primary radical termination could not be neglected, as evidenced by kinetic analysis. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 846–852, 2004
Photopolymerization of acrylates without photoinitiators with short‐wavelength UV radiation: A study with real‐time fourier transform infrared spectroscopy
Authors: Scherzer T.
Published: January 2004

This article reports on the UV photopolymerization of acrylates without photoinitiators. Initiation of the reaction was achieved by direct excitation of the acrylates during irradiation with short‐wavelength UV light by use of the 222‐nm emission of a KrCl* excimer lamp. The reactivity of various acrylates was studied by real‐time Fourier transform infrared–attenuated total reflection spectroscopy. The rate and the extent of the reaction within the layer were strongly dependent on the depth of penetration of UV light, which was determined by the molar extinction coefficient of the acrylate. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 894–901, 2004
Micron‐granula polyolefin with self‐immobilized nickel and iron diimine catalysts bearing one or two allyl groups
Authors: Jin Guoxin , Zhang Dao
Published: January 2004

Self‐immobilized nickel and iron diimine catalysts bearing one or two allyl groups of [ArNC]2(C10H6)NiBr2 [Ar = 4‐allyl‐2,6‐(i‐Pr)2C6H2] (1), [ArNC(Me)][Ar′N C(Me)]C5H3NFeCl2 [Ar = Ar′ = 4‐allyl‐2,6‐(i‐Pr)2C6H3, Ar = 2,6‐(i‐Pr)2C6H3, and Ar′ = 4‐allyl‐2,6‐(i‐Pr)2C6H3] were synthesized and characterized. All three catalysts were investigated for olefin polymerization. As a result, these catalysts not only showed high activities as the catalyst free from the allyl group, such as [ArNC]2C10H6NiBr2 (Ar = 2,6‐(i‐Pr)2C6H2)], but also greatly improved the morphology of polymer particles to afford micron‐granula polyolefin. The self‐immobilization of catalysts, the formation mechanism of microspherical polymer, and the influence on the size of the particles are discussed. The molecular structure of self‐immobilized nickel catalyst 1 was also characterized by crystallographic analysis. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1018–1024, 2004
Morphology and nonisothermal crystallization of in situ microfibrillar poly(ethylene terephthalate)/polypropylene blend fabricated through slit‐extrusion, hot‐stretch quenching
Authors: Li Zhong‐Ming , Yang Wei , Li Liang‐Bin , Xie Bang‐Hu , Huang Rui , Yang Ming‐Bo
Published: January 2004

This study describes the morphology and nonisothermal crystallization kinetics of poly(ethylene terephthalate) (PET)/isotactic polypropylene (iPP) in situ micro‐fiber‐reinforced blends (MRB) obtained via slit‐extrusion, hot‐stretching quenching. For comparison purposes, neat PP and PET/PP common blends are also included. Morphological observation indicated that the well‐defined microfibers are in situ generated by the slit‐extrusion, hot‐stretching quenching process. Neat iPP and PET/iPP common blends showed the normal spherulite morphology, whereas the PET/iPP microfibrillar blend had typical transcrystallites at 1 wt % PET concentration. The nonisothermal crystallization kinetics of three samples were investigated with differential scanning calorimetry (DSC). Applying the theories proposed by Jeziorny, Ozawa, and Liu to analyze the crystallization kinetics of neat PP and PET/PP common and microfibrillar blends, agreement was found between our experimental results and Liu's prediction. The increases of crystallization temperature and crystallization rate during the nonisothermal crystallization process indicated that PET in situ microfibers have significant nucleation ability for the crystallization of a PP matrix phase. The crystallization peaks in the DSC curves of the three materials examined widened and shifted to lower temperature when the cooling rate was increased. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 374–385, 2004
Unique morphological and thermal behaviors of reorganized poly(ethylene terephthalates)
Authors: Wei Min , Bullions Todd A. , Rusa Cristian C. , Wang Xingwu , Tonelli Alan E.
Published: January 2004

Bulk poly(ethylene terephthalate) PET has been reorganized both morphologically and conformationally by processing from its inclusion complex (IC) formed with γ‐cyclodextrin (CD). In the narrow channels of its γ‐CD‐IC crystals the included guest PET chains are isolated from neighboring PET chains and the ethylene glycol (EG) units adopt the highly extended g±tg∓ kink conformations, whose cross‐sectional diameters are ∼80% of the diameter of the fully extended, all‐trans crystalline PET conformer, though they are nearly (∼95%) as extended. When the highly extended, unentangled guest PET chains are coalesced from their γ‐CD‐IC crystals by exposure to hot water, host γ‐CDs are removed and the PET chains are presumably consolidated into a bulk sample with a morphology and constituent chain conformations not normally found in PET samples solidified from their randomly coiling, possibly entangled, disordered melts and solutions. Observations by polarized light and atomic force microscopies provide visual evidence for widely different semicrystalline morphologies developed in coalesced and as‐received PETs when crystallized from their melts, with possibly chain extended, small crystals and spherulitic, chain‐folded, large crystals, respectively. DSC observations reveal that coalesced PET is rapidly crystallizable from the melt, while as‐received PET is slow to crystallize and is easily quenched into a totally amorphous sample. Analyses of 13C‐NMR data strongly indicate that the PET chains in the noncrystalline regions of the coalesced sample remain predominantly in the highly extended kink conformations, with g±tg∓ EG units, which are required by their inclusion into PET‐γ‐CD‐IC crystals, while the predominantly amorphous PET chains in the as‐received sample have high concentrations of gauche± CH2CH2 and trans OCH2,CH2O EG bond conformations. 13C‐NMR T1(13C) and T1ρ(1H) relaxation studies show no evidence of a glass transition for coalesced PET, while the as‐received sample shows abrupt changes in both the MHz [T1(13C)] and kHz [T1ρ(1H)] motions at T ∼ Tg. Preliminary observations of differences in their macroscopic properties are attributed to the very different morphologies and conformations of the constituent chains in these PET samples. Apparently the kink conformers in the noncrystalline regions of coalesced PET are at least partially retained for extended periods even in the melt and are rapidly crystallized upon cooling. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 386–394, 2004
Temperature‐responsive linear polyelectrolytes and hydrogels based on [2‐(methacryloyloxy)ethyl] trimethylammonium chloride and N‐isopropylacrylamide and their complex formation with potassium hexacyanoferrates (II, III)
Authors: Khutoryanskiy V. V. , Nurkeeva Z. S. , Mun G. A. , Sergaziyev A. D. , Kadlubowski S. , Fefelova N. A. , Baizhumanova T. , Rosiak J. M.
Published: January 2004

Water‐soluble temperature‐responsive polyelectrolytes and hydrogels have been synthesized by γ‐radiation copolymerization of [2‐(methacryloyloxy)‐ethyl]trimethylammonium chloride with N‐isopropylacrylamide. Complex formation of soluble copolymers with potassium hexacyanoferrates (II, III) was studied in aqueous solutions. It was shown that, depending on the concentration and temperature, the formation of soluble or insoluble polycomplexes is observed. The hydrogels show good ability to absorb potassium hexacyanoferrates (II, III) from aqueous solutions. Sorption ability of hydrogels depends on the content of cationic monomer in copolymer and the nature of coordination ion. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 515–522, 2004
Melt spinning and laser‐heated drawing of a new semiaromatic polyamide, PA9‐T fiber
Authors: Jalal Uddin Ahmed , Ohkoshi Y. , Gotoh Y. , Nagura M. , Endo R. , Hara T.
Published: January 2004

Fibers of PA9‐T, a new semiaromatic polyamide containing a long aliphatic chain, were prepared by melt spinning. As‐spun fibers were subsequently drawn with a CO2 laser‐heated drawing system at different draw ratios and various drawing velocities. On‐line observations of drawing points deciphered two drawing states; namely, flow drawing and neck drawing, over the entire range of drawing. Drawing stress revealed that flow drawing is induced by slight drawing stress under a low draw ratio up to 3, and neck drawing is induced by relatively high drawing stress under a higher draw ratio. The effect of drawing stress and drawing velocity on the development of the structure and properties has been characterized through analysis of birefringence, density, WAXD patterns, and tensile, thermal, and dynamic viscoelastic properties. For the neck‐drawn fibers, almost proportional enhancements of crystallinity and molecular orientation with drawing stress were observed. The flow‐drawn fibers have an essentially amorphous structure, and birefringence and density do not always have a linear relation with properties. The fibers drawn at high drawing speed exhibit improved fiber structure and superior mechanical properties. The maximum tensile strength and Young's modulus of PA9‐T drawn fibers were found to be 652 MPa and 5.3 GPa, respectively. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 433–444, 2004
Fiber property and structure development of polyester blend fibers reinforced with a thermotropic liquid‐crystal polymer
Authors: Kim Jun Young , Kim Seong Hun , Kikutani Takeshi
Published: January 2004

Ternary blend fibers (TBFs), based on melt blends of poly(ethylene 2,6‐naphthalate), poly(ethylene terephthalate), and a thermotropic liquid‐crystal polymer (TLCP), were prepared by a process of melt blending and spinning to achieve high‐performance fibers. The reinforcement effect of the polymer matrix by the TLCP component, the fibrillar structure with TLCP fibrils of high aspect ratios, and the development of more ordered and perfect crystalline structures by an annealing process resulted in the improvement of the tensile strength and modulus for the TBFs. An increase in the apparent crystallite size with the spinning speed was attributed to the development of larger crystallites and more ordered crystalline structures in the annealed TBFs. The birefringence and density of the TBFs increased with increasing spinning speed, the TBFs becoming more oriented and the crystal packing becoming more enhanced. The molecular orientation was an important factor in determining the tensile strength and modulus of the TBFs. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 395–403, 2004
Space charge distribution in bending‐electrostrictive polyurethane films doped with salts
Authors: Watanabe Masashi , Hirai Toshihiro
Published: January 2004

Polyurethane films bent during a field application (1.5 MV/m). Doping the films with salts controlled the bending direction. With ZnBr2, Zn(ClO4)2, and Cu(ClO4)2 as the dopants, the films bent to the anode side. Contrarily, CH3COONa‐doped, NaBr‐doped, and undoped films bent to the cathode side. We also measured the space charge distribution in the films to clarify the factor that determined the direction. The measurements were carried out with a pulsed electroacoustic method. For the films that bent to the anode side, a positive space charge was observed inside the cathode during the field application. However, for the films that bent to the cathode side, there was a negative space charge inside the anode. Thus, the dopants also controlled the space charge distribution, which corresponded to the bending direction. These results suggested a causality between the field‐induced bend of the film and the space charge distribution. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 523–531, 2004
Plasticized microporous poly(vinylidene fluoride) separators for lithium‐ion batteries. II. Poly(vinylidene fluoride) dense membrane swelling behavior in a liquid electrolyte—characterization of the swelling kinetics
Authors: Saunier J. , Alloin F. , Sanchez J. Y. , Barrière B.
Published: January 2004

Some microporous poly(vinylidene fluoride) (PVdF) separators for lithium‐ion batteries, used in liquid organic electrolytes based on a mixture of carbonate solvents and lithium salt LiPF6, were characterized by the study of the swelling phenomena on dense PVdF membranes. Various aspects of the kinetics of the carbonate solvents and the solvent mixture sorption in dense PVdF slabs were studied at different temperatures. Non‐Fickian behavior, characterized by S‐shaped sorption curves, was highlighted, and a salt effect, which resulted in two‐stage sorption, was studied. Diffusion coefficients and activation energies were calculated for the Fickian portions of the sorption curves, that is, at short times and low swelling ratios. A strong influence of the different interaction parameters was shown for the swelling kinetics. This study proved that the swelling of microporous PVdF membranes could be considered instantaneous. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 544–552, 2004
Plasticized microporous poly(vinylidene fluoride) separators for lithium‐ion batteries. I. Swelling behavior of dense membranes with respect to a liquid electrolyte—Characterization of the swelling equilibrium
Authors: Saunier J. , Alloin F. , Sanchez J. Y. , Barrière B.
Published: January 2004

Some poly(vinylidene fluoride) (PVdF) microporous separators for lithium‐ion batteries, used in liquid organic electrolytes based on a mixture of carbonate solvents and lithium salt LiPF6, were characterized by the study of the swelling phenomena on dense PVdF membranes. We were interested in the evolution of the swelling ratios with respect to different parameters, such as the temperature, swelling solution composition, and salt concentration. To understand PVdF behavior in microporous membranes and, therefore, to have a means of predicting its behavior with different solvent mixtures, we correlated the swelling ratios in pure solvents and in solvent mixtures to the solvent–polymer interaction parameters and solvent–solvent interaction parameters. We attempted a parametric identification of swelling curves with a very simple Flory–Huggins model with relative success. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 532–543, 2004
Surface roughness in dynamically crystallized isotactic polypropylene films
Authors: González V. A. , Alanís M. , Guerrero C. , Ortiz U.
Published: January 2004

The relationship between the dynamic crystallization conditions and surface topography of iso‐polypropylene (i‐PP) films was examined with fractal geometry. When i‐PP was crystallized from a melt at cooling rates in the range between 1 and 100 °C/min, the generated surface topography presented self‐affine behavior at least in the scale range from 0.1 to 100 μm. Moreover, the calculated roughness exponent of these surfaces increased with the cooling rate used to crystallize the samples, which meant a smoother surface at higher crystallization rates. This behavior could be qualitatively explained in terms of the temperature effect on the nucleus stability, the molecular mobility, and the surface tension. In addition, the morphology of quenched samples was analyzed, and different hypotheses were proposed to explain the unusual observed behavior. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 646–655, 2004
Molecular orientation of a ZnS‐nanocrystal‐modified M13 virus on a silicon substrate
Authors: Ni Jingping , Lee Seung‐Wuk , White John M. , Belcher Angela M.
Published: January 2004

The surface structure and cast film formation process of a ZnS‐nanocrystal‐modified M13 bacteriophage (ZnS–M13) were investigated. A ZnS–M13 film oriented under the influence of a capillary force was obtained on both single‐crystal and polycrystalline substrates. The film formation process was investigated with atomic force microscopy and scanning electron microscopy. The surface images showed that the degree of orientation of the molecular long axes greatly depended on the direction of force and the concentration of aqueous solutions. Controlling the aqueous solution concentration yielded a highly oriented ZnS–M13 film on an indium tin oxide plate. The ability to control the orientation of virus‐based films may lead to new types of hybrid materials in which the components are organized on several length scales. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 629–635, 2004
Anomalous small‐angle X‐ray scattering characterization of composites based on sulfonated poly(ether ether ketone), zirconium phosphates, and zirconium oxide
Authors: Prado L. A. S. De A. , Wittich H. , Schulte K. , Goerigk G. , Garamus Vasil M. , Willumeit R. , Vetter S. , Ruffmann B. , Nunes S. P.
Published: January 2004

The morphology and distribution of zirconium oxide and zirconium phosphates in a matrix of sulfonated poly(ether ether ketone) (SPEEK) were investigated with anomalous small‐angle X‐ray scattering (ASAXS) and electron microscopy. ASAXS revealed that ZrO2 was distributed in the SPEEK matrix in the form of nanoparticles smaller than 13 Å. A decrease in the conductivity suggested that the sulfonic groups were bound to the zirconium oxo species at the particle surface. Furthermore, two kinds of membranes containing zirconium phosphate were investigated. In one case, the phosphate was directly dispersed in the polymer solution for the casting of the membrane. In the other case, the phosphate was previously treated with n‐propyl ammonium and polybenzimidazole. From ASAXS data, the fractal dimension could be estimated. Mass‐fractal behavior was confirmed for the SPEEK membrane containing previously exfoliated zirconium phosphate, with aggregates of 6.3–165 Å. Surface‐fractal behavior was detected for membranes with untreated phosphates, with aggregates of 6.4–185 Å. The untreated phosphates caused an increase in the permeability, without changing the proton conductivity much. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 567–575, 2004
Crystallization kinetics in shearing‐induced oriented and stretched poly(ethylene oxide)
Authors: Jiang Shichun , An Lijia , Jiang Bingzheng
Published: January 2004

Isothermal crystallization kinetics in the melting of poly(ethylene oxide) (PEO) were investigated as a function of the shear rate and crystallization temperature by optical microscopy. The radial growth rates of the spherulites are described by a kinetics equation including shearing and relaxation combined effects and the free energy for the formation of a secondary crystal nucleus. The free‐energy difference between the liquid and crystalline phases increased slightly with rising shearing rates. The experimental findings showed that the influence of the relaxation of PEO, which is related to the shear‐induced orientation and stretch in a PEO melt, on the rate of crystallization predominated over the influence of the shearing. This indicated that the relaxation of PEO should be more important so that the growth rates increase with shearing, but it was nearly independent of the shear rate within the measured experimental range. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 656–665, 2004
Functional and anatomical effects of hormonally induced experimental prostate growth: A urodynamic model of benign prostatic hyperplasia (BPH) in the beagle
Authors: Yokota Takeshi , Honda K. , Tsuruya Y. , Nomiya M. , Yamaguchi Osamu , Gotanda K. , Constantinou Christos E.
Published: January 2004

BACKGROUND

Benign prostatic hypertrophy (BPH) produces a variety of changes in the urodynamic pattern of micturition and is usually associated with high detrusor voiding pressure and poor urine flow‐rate. In most previous experimental models, designed to simulate this condition, some degree of obstruction is immediately imposed by the technique employed to produce urethral occlusion. Consequently these models cannot reproduce the gradual onset of obstruction. In the present study a canine prostatic enlargement model, using 5α‐dihydrotestosterone (DHT) + 17β‐estradiol (E) was adapted in order to produce a more gradual onset of partial obstruction and impaired voiding.

MATERIALS AND METHODS

Hormonally induced prostatic enlargement was produced using seven beagles, given DHT 75 mg/day together with E 0.75 mg/day for 28 days via an implantable pump. The functional effects of DHT + E treatment on micturition pressure/flow were measured in the conscious animal. Identical measurements were also made using a separate older group of five beagles with symptoms of BPH. In addition seven beagles similarly instrumented were used as controls.

RESULTS

Pressure/flow studies show that DHT + E produced obstructive micturition, characterized by a significantly increased micturition detrusor pressure, from 33.3 ± 10.5 to 50.8 ± 10.7 cmH2O and significantly decreased low urine flow‐rate from 8.6 ± 2.1 to 6.9 ± 0.9 ml/sec. Associated with the obstructive micturition, this treatment increased wet prostate weight from 11.9 ± 2.5 to 31.6 ± 10.0 g. Prostate volume of the BPH beagles was 29.3 ± 8.9 g. Morphologic studies show that DHT + E produced epithelial hyperplasia extending focally into the lumen.

CONCLUSIONS

Hormonally induced prostate growth produced bladder obstruction, in terms of pressure/flow characteristics, that are analogous to BPH. It is suggested that this type of hormonal treatment can be used to create a model for the study of the effects of controlled increased in prostate growth and the development of BPH on micturition. © 2003 Wiley‐Liss, Inc.
Modulation of phenotype of human prostatic stromal cells by transforming growth factor‐betas
Authors: Hisataki Toshihiro , Itoh Naoki , Suzuki Kazuhiro , Takahashi Atsushi , Masumori Naoya , Tohse Noritsugu , Ohmori Yuki , Yamada Shizuo , Tsukamoto Taiji
Published: January 2004

BACKGROUND

We investigated the effects of transforming growth factor (TGF)‐betas on morphological and receptor phenotypes, as well as proliferation of four currently established human prostatic myofibroblast cell lines and one commercially available prostatic stromal cell line.

METHODS

The effects of TGF‐betas on morphological changes and proliferation of the cells were studied by immunohistochemistry and bromodeoxyuridine assay, respectively. The expression of alpha 1‐receptor subtypes was measured by real time quantitative reverse transcription‐polymerase chain reaction (RT‐PCR) and the radioligand binding assay for the receptors was also performed.

RESULTS

TGF‐betas 1, 2, and 3 induced expression of desmin and myosin of cells of the established cell lines, and significantly inhibited their growth. The alpha 1a‐receptor was expressed only in the commercially available cell line and alpha 1b and 1d, in all cell lines. TGF‐beta 1 suppressed the expression of all three subtypes of the alpha 1‐receptor. The binding sites of cells of all the cell lines were reduced by treatment with this growth factor.

CONCLUSIONS

TGF‐betas may induce human prostatic stromal cells to express the smooth muscle phenotype and inhibited their growth. However, the growth factor reduced the binding sites of the receptor and suppressed mRNA expression of its subtypes, suggesting that morphological and receptor phenotypes may be regulated via more than one pathway by TGF‐beta(s). © 2003 Wiley‐Liss, Inc.
Apolipoprotein‐D: A novel cellular marker for HGPIN and prostate cancer
Authors: Hall R.E. , Horsfall D.J. , Stahl J. , Vivekanandan S. , Ricciardelli C. , Stapleton A.M.F. , Scardino P.T. , Neufing P. , Tilley Wayne D.
Published: January 2004

BACKGROUND

High grade prostatic intraepithelial neoplasia (HGPIN) is a putative pre‐malignant lesion of the prostate. While apolipoprotein‐D (Apo‐D), an androgen‐regulated hydrophobic transporter protein, is expressed in prostate tumors, its expression in HGPIN is unknown.

METHODS

Immunoreactivity for Apo‐D and another androgen‐regulated protein, prostate specific antigen (PSA), was investigated in 64 radical prostatectomy tissues by video image analysis.

RESULTS

Eighty two percent of prostatectomy specimens demonstrated moderate to strong Apo‐D immunoreactivity in areas of HGPIN. In comparison, weak Apo‐D immunoreactivity was observed in non‐malignant areas in only 24% of specimens. The median (range) percentage cellular area of HGPIN immunopositive for Apo‐D (9.7%, 0–42.9), and the cellular concentration of Apo‐D (MIOD 3.1, 0–13.3), were intermediate between that of normal (area 0%, 0–53.5%, MIOD 0, 0–12.6) and early stage prostate cancer tissues (area 29.2%, 0–90.8%, MIOD 6.7, 0–28.1). This increase in Apo‐D expression from non‐malignant, through HGPIN to prostate cancer was statistically significant (P < 0.001), and contrasted with the decrease observed in PSA staining between adjacent areas of normal glands, HGPIN, and cancer (P = 0.026).

CONCLUSIONS

The presence of high levels of immunoreactive Apo‐D in HGPIN and prostate cancer, but not in non‐malignant epithelial cells, is consistent with HGPIN being an intermediate lesion in the transition to prostate cancer, and suggests that cellular Apo‐D expression is a marker of malignant transformation of the prostate. © 2003 Wiley‐Liss, Inc.
Generalized electronic diabatic scheme: Diagonalizing the electronic Hamiltonian for artificial molecular systems. How do molecular meccanos move?
Authors: Tapia O.
Published: January 2004

A quantum–classic model is presented and used to describe systems ranging from normal molecules up to electronic systems sensed in real space. The quantum system is a set of n‐electrons; a positive background in real space completes the model. A generalized electronic diabatic (GED) theory is introduced. The diabatic functions diagonalize the electronic Hamiltonian for any arrangement of the positive background. Physical quantum states are represented as linear superpositions in the diabatic basis; this latter is always fixed. For systems sensed in real space, the coefficients of the linear superposition are functions of the real space configuration coordinates. Physical changes are produced by interactions with external sources/sinks of energy. An interaction couples different diabatic states; diagonalizing the electronic Hamiltonian plus the couplings leads to new coefficients describing physical states. Among other things, these couplings can be used to simulate the effects produced by scanning tunneling microscopy, atomic force, and transmission electron microscopy on substrates located in real space. The important thing is that time–evolution in electronic Hilbert space can be related to actual motion in real space. The experiment of lateral hopping of a substrate on a metallic surface induced by vibration excitation and followed with scanning tunneling microscope is discussed. A result of the present work is that motion of molecular meccanos reflects then time–evolution in electronic Hilbert space. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
A measure of electron localizability
Authors: Kohout M.
Published: January 2004

A functional of the same‐spin electron pair density is proposed as a measure of electron localizability. This functional yields the average number of same‐spin electron pairs in a region Ω enclosing a fixed charge. The functional equals zero if the fixed charge in Ω originates from one electron only, with all other same‐spin electrons outside the region Ω. Then, the correlation of the electronic motion in Ω and thus the localizability of an electron is high. If the motion of the same‐spin electrons becomes less correlated, more electrons participate in the fixed charge contained in Ω, the average number of same‐spin electron pairs (the functional) increases. In the Hartree–Fock approximation the Taylor expansion of the proposed localizability functional can be related to the electron localization function of Becke and Edgecombe without using an arbitrary reference to the uniform electron gas. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Finite‐element calculations for the helium atom
Authors: Zheng Weiying , Ying Lung‐An
Published: January 2004

We give the explicit form of the Hylleraas–Breit transform in the current paper and apply it to fixed‐nucleus problems of heliumlike ions. Employing the relation between the total angular momentum and the Hamilton, the six‐dimensional Schrödinger equation is transferred into three‐dimensional systems of equations. We use the Lagrange finite‐element method to obtain numerical solutions for some low‐lying S, 1s2p 3P, and 1s3d 3D states of the helium atom. The relative errors of our approximate energies are: O(10−8) a.u. for S states, O(10−7) a.u. for 1s2p 3P state and O(10−5) a.u. for 1s3d 3D state. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
The quantum measurement problem
Authors: Fidder Henk , Tapia O.
Published: January 2004

The measurement problem in quantum mechanics still appears to be an unresolved issue. Here we present a new quantum theory of measurement that overcomes many of the difficulties previously found. It is based on a consistent use of the linear superposition principle and distinguishes two aspects: recording and observation. A recording elicits the full interaction of the object quantum system with the quantum measuring apparatus. No wavefunction collapse is introduced. Statistics may appear at the observation of the recording only and depends on filtering processes. The theory presented here uses the existing mathematical structure of quantum mechanics but requires no ad hoc measurement postulates. Well‐known paradoxical aspects in standard quantum mechanics, for instance, wave–particle duality, Schrödinger's cat, and Zeno effects do not appear in the current formulation. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004