bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermoformability study of virgin and regrind high impact polystyrene coextruded sheets: Influence of the number of processing cycles on the processing parameters
Authors: Soriano Florentino , Morales Graciela , de León Ramón Díaz , Belmontes Felipe Avalos 
Published: February 2006

AbstractHigh impact polystyrene was extruded repeatedly at 220°C and thermoformed under different heat time (Ht), plug assist time (PAt), mold time (Mt), and mold temperature (MT). The optimum thermoforming process conditions were determined for a material processed in one cycle, using an experimental design of the four variables mentioned before at two levels. Mt has no influence on the coefficient of wall thickness variation (CV), while the rest of the variables present a noticeable influence on CV, and they can be modified to obtain lower values of CV (i.e. CV = 1.3, using Ht = 46 s, PAt = 2.5 s, and MT = 80°C). These conditions were then employed for a material processed under six cycles, resulting in an increase in the CV value to 3.5. The normalized thickness (NT) of HIPS with one and six processing cycles was also evaluated. It depends on Ht, Mt, and PAt. With the values of the calculated parameters for CV, it was possible to obtain NT values close to 1, using a material processed one cycle. The NT value obtained for six cycles processed HIPS was far from unity. The changes on thermoforming variables' responses are a consequence of the changes occurred in HIPS inner structure. POLYM. ENG. SCI. 46:503–509, 2006. © 2006 Society of Plastics Engineers.
Optical properties of highly transparent polypropylene cast films: Influence of material structure, additives, and processing conditions
Authors: Resch Katharina , Wallner Gernot M. , Teichert Christian , Maier Günther , Gahleitner Markus 
Published: February 2006

AbstractPolypropylene homopolymers and ethylene/propylene‐random‐copolymers formulated with and without anti‐blocking additives were extruded to cast films with an industrial scale extruder equipped with a soft box, a specific air knife that expels a higher volume of air at lower velocity. The films were analyzed as to their optical properties haze and clarity. A comprehensive topographical characterization was performed using atomic force microscopy (AFM) and confocal microscopy. To obtain morphological information on a nanometer scale AFM phase imaging, micro‐thermal analysis and small angle X‐ray scattering (SAXS) were done. A significant effect of additives and processing conditions on the film topography and the optical properties was revealed. The films without anti‐blocking and antacid aids showed the best optical properties and lowest vertical roughness fluctuations. In contrast, the addition of anti‐blocking and antacid aids reduced the optical properties associated with an increase in surface roughness. While for films without anti‐blocking aids an enhanced soft box condition resulted in lower vertical fluctuations of roughness and better optical properties, the behavior was in reverse for films with anti‐blocking aid. By means of SAXS crystalline lamellae with a thickness of about 2.5 nm were detected. High‐resolution phase imaging AFM yielded thicker crystal lamellae on the film surface. POLYM. ENG. SCI., 46:520–531, 2006. © 2006 Society of Plastics Engineers.
Injection molding product weight: Online prediction and control based on a nonlinear principal component regression model
Authors: Yang Yi , Gao Furong 
Published: February 2006

AbstractWeight is an important quality characteristic of injection‐molding products. The current work focuses on the online prediction and closed‐loop control of the product weight. Previous researchers used the process set‐points as the inputs to establish weight prediction model. These models cannot reflect the weight variations at a given setting. In this study, an online weight prediction model has been developed, with the process variable trajectories as the inputs, using a principal component regression (PCR) model. A nonlinear enhancement has been made to improve the prediction accuracy of the PCR weight model. Based on such an online prediction, a closed‐loop weight control system has been developed and tested experimentally. POLYM. ENG. SC. 46:540–548, 2006. © 2006 Society of Plastics Engineers
A multidimensional proteomic approach to identify hypertrophy‐associated proteins
Authors: Lindsey Merry L. , Goshorn Danielle K. , Comte‐Walters Susana , Hendrick Jennifer W. , Hapke Elizabeth , Zile Michael R. , Schey Kevin 
Published: February 2006

AbstractLeft ventricular hypertrophy (LVH) is a leading cause of congestive heart failure. The exact mechanisms that control cardiac growth and regulate the transition to failure are not fully understood, in part due to the lack of a complete inventory of proteins associated with LVH. We investigated the proteomic basis of LVH using the transverse aortic constriction model of pressure overload in mice coupled with a multidimensional approach to identify known and novel proteins that may be relevant to the development and maintenance of LVH. We identified 123 proteins that were differentially expressed during LVH, including LIM proteins, thioredoxin, myoglobin, fatty acid binding protein 3, the abnormal spindle‐like microcephaly protein (ASPM), and cytoskeletal proteins such as actin and myosin. In addition, proteins with unknown functions were identified, providing new directions for future research in this area. We also discuss common pitfalls and strategies to overcome the limitations of current proteomic technologies. Together, the multidimensional approach provides insight into the proteomic changes that occur in the LV during hypertrophy.
A proteomic approach to verifyin vivoexpression of a novel γ‐gliadin containing an extra cysteine residue
Authors: Ferrante Paola , Masci Stefania , D'Ovidio Renato , Lafiandra Domenico , Volpi Chiara , Mattei Benedetta 
Published: February 2006

AbstractGliadins and glutenins are the main protein fractions present in wheat gluten. They are responsible for technological and nutritional quality of wheat based products. In particular, glutenins are mainly responsible for dough visco‐elastic properties, whereas gliadins confer extensibility to dough and are the most important factor triggering celiac disease, the major human intolerance to gluten. Gliadins are monomeric proteins, whereas glutenins are polymers stabilized by disulfide bonds. Although they have distinctive structural characteristics, it is possible that some gliadins become part of the glutenin fraction because of mutations that affect cysteine number and distribution. Here, we provide evidence that a naturally mutated γ‐gliadin with an extra cysteine residue is incorporated into the polymeric fraction. This goal was achieved using an integrated approach involving heterologous expression, 2‐DE, RP‐HPLC and MS.
Synthesis of SAN‐containing block copolymers using RAFT polymerization
Authors: Fan Deqin , He Junpo , Xu Jiangtao , Tang Wei , Liu Yang , Yang Yuliang 
Published: February 2006

AbstractCopolymerization of styrene and acrylonitrile was carried out via reversible addition‐fragmentation chain transfer process (RAFT) in the presence of cumyl dithiobenzoate with AIBN as initiator. Copolymerization proceeded in a controlled/“living” fashion, and the copolymer composition depended on the feed ratio of monomer pairs. Block copolymers comprising styrene and acrylonitrile (SAN) segments and various functional blocks were synthesized through chain extension using the first blocks as macromolecular chain transfer agents (macroCTAs). Since the polymerization of both blocks proceeded through the RAFT process, the resulting block copolymers exhibited relatively narrow molecular weight distribution, with polydispersity indices in the range of 1.29–1.46. Gel permeation chromatography (GPC), and 1H NMR and FTIR measurements confirmed the successful synthesis of the functionalized block copolymers. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2260–2269, 2006
Probing the use of small‐angle light scattering for characterizing structure of titanium dioxide/low‐density polyethylene nanocomposites
Authors: Xiao Zhicheng , Li Ying , Ma Dongling , Schadler Linda S. , Akpalu Yvonne A. 
Published: February 2006

AbstractSmall‐angle light scattering (SALS) measurements were used to study the structure of titanium dioxide (TiO2)/low‐density polyethylene (LDPE) nanocomposites. The results showed that the scattering from LDPE crystalline structures and the scattering from TiO2 nanoparticles can be resolved and separated. It is shown that the independent effects of crystallization conditions and the presence of nanoparticle aggregates on the spherulitic structure of the LDPE matrix can be determined by analyzing the scattering patterns using the methods proposed. From the SALS results, we conclude that the nanoparticle surface chemistry affects both nucleation of spherulites and their structure particularly under rapid cooling conditions. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1084–1095, 2006
Treating the polyelectrolytes as polymers with a draining effect. II. The behavior in the gel permeation chromatography
Authors: Dondos Anastasios 
Published: February 2006

AbstractThe behavior of the polyelectrolytes in the gel permeation chromatography (GPC) can be better understood if the modified universal calibration (log([η]M/Φ) vs. elution volume) is used instead of the “classical” universal calibration (log[η]M vs. elution volume). The value of Flory's parameter Φ is obtained from an equation established for nonionic polymers presenting a draining effect, considering that polyelectrolytes also behave as polymers with a draining effect. The modified universal calibration does not apply as successfully to polyelectrolytes as to nonionic polymers, because of their electrostatic exclusion in the pore surface of the GPC columns. Nevertheless, when polyelectrolytes are found in a high salt concentration solution, the modified universal calibration can be used to obtain their molecular mass, using nonionic hydrosoluble polymers as standard polymers. Moreover, considering polyelectrolytes as polymers presenting a draining effect and applying the modified universal calibration provides a better explanation for the electrostatic exclusion of these polymers from the pores of the GPC columns, using the Dubin–Tecklenburg model. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1106–1113, 2006
Morphology, electrical resistance, electromagnetic interference shielding and mechanical properties of functionalized MWNT and poly(urea urethane) nanocomposites
Authors: Wu Han‐Lang , Ma Chen‐Chi M. , Yang Yu‐Ting , Kuan Hsu‐Chiang , Yang Cheng‐Chien , Chiang Chin‐Lung 
Published: February 2006

AbstractThe functionalized multi‐walled carbon nanotubes (MWNT) had been prepared by free radical reaction with vinyltriethoxysilane. Polydimethylsiloxane (PDMS)‐based poly(urea urethane) (PUU) was also synthesized. PUU was further end‐capped with aminopropyltriethoxysilane (A‐silane), or with phenyltrimethoxysilane (P‐silane). Fourier transform infrared (FTIR), Raman spectra and thermogravimetric analysis (TGA) confirmed the functionalization of MWNT. The Mn and Mw of PUU were 85,123 and 235,876 g/mol, respectively. Both A‐silane end‐capped PUU and P‐silane end‐capped PUU showed improved dispersion of MWNT compared with that of PUU and MWNT. Moreover, the reduced discrepancy of surface electrical resistance of the two sides of the MWNT/PUU nanocomposite film was found due to the homogeneous dispersion of MWNT. The microwave absorption and tensile strength of MWNT/PUU were also improved by the well dispersion of MWNT in PUU matrix. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1096–1105, 2006
Effect of the environment on the stability of surfactant–polypeptide self‐assembled complexes: Molecular dynamics simulations of stoichiometric complexes formed by N‐dodecyltrimethylammonium and poly(α,L‐glutamate) in chloroform, methanol, and water
Authors: Zanuy David , Alemán Carlos 
Published: February 2006

AbstractA series of molecular dynamics simulations have been performed to study the supramolecular structure of self‐assembled complexes formed by N‐dodecyltrimethylammonium cations and the synthetic polypeptide poly(α,L‐glutamate). The influence of the type of solvent has been investigated, considering explicit environments of chloroform, water, and methanol on a stoichiometric complex containing 15 residues. In chloroform, the complex stabilizes in a regular structure: the polypeptide adopts an α‐helix conformation that is regularly surrounded by surfactant molecules to form electrostatic interactions through a multiple interaction pattern. However, this structure destabilizes in methanol and water: (a) the α‐helix unfolds in the two solvents and (b) the electrostatic links between the surfactant molecules and the polyanion are disrupted in aqueous solution, although these interactions are still preserved in methanol. The role of the solvent environment in stabilizing or destabilizing the polypeptide secondary structure, the organization of the surfactant molecules, and predominantly the surfactant–polypeptide supramolecular organization is discussed in detail. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1122–1133, 2006
Changes in lung function measured by spirometry and the forced oscillation technique in cystic fibrosis patients undergoing treatment for respiratory tract exacerbation
Authors: Ren Clement L. , Brucker Justin L. , Rovitelli Amy K. , Bordeaux Kimberly A. 
Published: February 2006

AbstractObjective measures of lung function are critical for the treatment and study of lung diseases such as cystic fibrosis (CF). Spirometry is the most widely used and accepted method of pulmonary function testing in CF, but not all patients can perform the maneuvers required to obtain valid results from spirometry. The forced oscillation technique (FOT) requires less cooperation than spirometry. The goals of this study were to determine if FOT could detect changes in lung function in CF patients receiving inpatient treatment of respiratory tract exacerbations (RTEs), and to gather preliminary data on the magnitude of these changes and the variability of FOT data in such patients. We performed a retrospective chart review of CF patients admitted to the hospital for RTEs. We identified 14 patients who had both spirometry and FOT performed at the beginning and end of their treatment course. Their mean age was 15.9 years (range, 8–18). The mean forced expiratory volume in 1 sec (FEV1) on admission was 62.57% predicted. FEV1 increased by 27.1 ± 33.15% (mean ± SD, P = 0.008). The absolute value of reactance at 5 Hz (X5) decreased by 22.3 ± 25.1% (P = 0.005), while resistance at 5 Hz decreased by 11.6 ± 17.3% (P = 0.025). There was a significant relationship between changes in FEV1 and X5 (P = 0.003, r2 = 0.54). Our study demonstrates that FOT can detect significant changes in lung function in CF patients receiving treatment for RTEs. We speculate that FOT can serve as an alternative method to measure lung function in CF patients unable to perform spirometry, such as young children. Pediatr. Pulmonol. © 2006 Wiley‐Liss, Inc.
Energy distribution of the universe in the Bianchi type II cosmological models
Authors: Aydogdu O. 
Published: February 2006

AbstractUsing the energy‐momentum complexes of Tolman, Papapetrou and Weinberg, the total energy of the universe in Locally Rotationally Symmetric (LRS) Bianchi type II models is calculated. The total energy is found to be zero due to the matter plus field. This result supports the viewpoint of Tryon, Rosen and Albrow.
Dependence of folding dynamics and structural stability on the location of a hydrophobic pair in β‐hairpins
Authors: Imamura Hideo , Chen Jeff Z. Y. 
Published: February 2006

AbstractWe study the dependence of folding time, nucleation site, and stability of a model β‐hairpin on the location of a cross‐strand hydrophobic pair, using a coarse‐grained off‐lattice model with the aid of Monte Carlo simulations. Our simulations have produced 6500 independent folding trajectories dynamically, forming the basis for extensive statistical analysis. Four folding pathways, zipping‐out, middle‐out, zipping‐in, and reptation, have been closely monitored and discussed in all seven sequences studied. A hydrophobic pair placed near the β‐turn or in the middle section effectively speed up folding; a hydrophobic pair placed close to the terminal ends or next to the β‐turn encourages stability of the entire chain. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Fetal cardiac calcifications: report of four prenatally diagnosed cases and review of the literature
Authors: Simchen M. J. , Toi A. , Silver M. , Smith C. R. , Hornberger L. K. , Taylor G. , Chitayat D. 
Published: February 2006

AbstractFetal cardiac calcifications are defined as diffuse hyperechogenicities in the different layers of the heart. This is an uncommon fetal ultrasound finding associated with significant myocardial dysfunction. We report four cases with massive fetal myocardial calcifications detected on prenatal ultrasound at 18–22 weeks' gestation and associated, in all cases, with significant cardiac dysfunction. Detailed fetal echocardiographic evaluation, chromosome analysis, and an extensive search for intrauterine infection as a cause of these abnormalities, were carried out on all cases. A thorough autopsy was performed on all deceased fetuses and postnatal investigation of the sole survivor was performed. Two of our patients chose to interrupt their pregnancies, one fetus suffered intrauterine demise, and one child was born alive. In all of our cases the karyotypes were normal, and no specific infectious etiology or maternal autoantibody was noted. Histopathology findings in the non‐survivors included myo‐ and epicardial calcification maximal at the base of the heart. The living child has findings suggestive of an intrauterine infection, although no infectious entity was identified. Long‐term follow‐up showed sensorineural hearing loss and severe developmental delay. Copyright © 2006 ISUOG. Published by John Wiley & Sons, Ltd.
The impact of two‐dimensional versus three‐dimensional ultrasound exposure on maternal–fetal attachment and maternal health behavior in pregnancy
Authors: Sedgmen B. , McMahon C. , Cairns D. , Benzie R. J. , Woodfield R. L. 
Published: February 2006

AbstractObjectiveTo explore the impact of timing and type of ultrasound, particularly three‐dimensional (3D), exposure on maternal–fetal attachment and maternal health behavior during pregnancy.MethodsSubjects were 68 women aged 18 years or older expecting their first child who presented for a routine ultrasound scan at around either 12 or 18 weeks' gestation in Nepean Hospital, Western Sydney. Women completed questionnaires assessing maternal–fetal attachment and health behavior, and were then allocated arbitrarily to either two‐dimensional (2D) or 3D ultrasound examination. Repeat questionnaires were completed 1 week later.ResultsMaternal–fetal attachment increased after both 2D and 3D ultrasound exposure, and the effect was moderated by the timing of exposure, with women receiving their first ultrasound examination at around 12 weeks showing the greatest change. Alcohol consumption was the only behavior to show significant change following ultrasound exposure, with a reduction in the reported average number of drinks per week. There was no significant difference in the pattern of change for 2D compared with 3D ultrasound exposure, and no effect of ultrasound exposure on maternal perception of the fetus.ConclusionsUltrasound has a positive impact on maternal–fetal attachment, particularly in the first trimester. 3D ultrasound did not offer enhanced benefits. Associations between ultrasound exposure and alcohol consumption warrant further investigation. Larger samples are needed to clarify the moderating effects of gestational age and type of ultrasound exposure. Copyright © 2006 ISUOG. Published by John Wiley & Sons, Ltd.
Insulin‐like Growth Factors (IGF) I and II Utilize Different Calcium Signaling Pathways in a Primary Human Parathyroid Cell Culture Model
Authors: Wong C. K. M. , Lai T. , Holly J. M. P. , Wheeler M. H. , Stewart C. E. H. , Farndon J. R. 
Published: February 2006

AbstractBackgroundIn most cell types, influx of calcium (Ca2+) induces a growth or secretory response. The opposite occurs in parathyroid (PTH), cells where there is an inverse relationship between intracellular Ca2+concentration and PTH secretion. We have examined the effects of calcium channel and metabolism modulators on insulin‐like growth factors (IGFs) in a parathyroid cell culture model.MethodsCell cultures were prepared from 9 patients undergoing operation for hyperparathyroidism. Following adhesion, the cells were transferred to serum‐free medium and dosed with IGF I, II ± ethyleneglycol‐bis(β‐aminoethyl)‐N, N, N′,N′‐tetraacetic acid (EGTA), nifedipine, nickel, 2‐aminoethoxy‐diphenylborate (2‐APB), or dantrolene. Proliferation (96 hours) was assessed by measuring tritiated thymidine incorporation and PTH release (1 and 3 hours) assayed by IRMA.ResultsBoth IGF I and II increased DNA synthesis to 162.8% ± 10.6% (SEM) and 131.1% ± 7.7%, respectively (P< 0.05). EGTA at 0.2 mmol (ionized Ca2+0.2mmol) did not affect the response to both IGFs. EGTA at 2 mmol (ionized Ca2+0 mmol) reduced the DNA synthesis of IGF I and II to 29% and 26%, respectively (P< 0.05). Nifedipine and nickel (nonspecific Ca2+channel blocker) were equally potent in negating the mitogenic effects of both IGFs. 2‐APB (IP3R blocker) reduced the basal DNA synthesis to 51.3% ± 8.4% but had no effect on either IGF. Dantrolene (ryanodine receptor blocker) negated IGF II induced mitogenisis (74.2% ± 6.7%) and partially inhibited IGF I mitogenesis (123% ± 6%) (P< 0.05). The rate of PTH secretion was greater after IGF II stimulation than after IGF I stimulation.ConclusionsIGFs I and II induce mitogenesis by different calcium signaling pathways. These data suggest that parathyroid cells may utilize different calcium signaling pathways to distinguish growth factors and serum calcium changes.
Preoperative Evaluation of Hepatic Vasculature by Three‐Dimensional Computed Tomographyin Patients Undergoing Hepatectomy
Authors: Kamiyama Toshiya , Nakagawa Takahito , Nakanishi Kazuaki , Kamachi Hirofumi , Onodera Yuya , Matsushita Michiaki , Todo Satoru 
Published: February 2006

AbstractBackgroundHepatectomy is particularly difficult when the tumor is large, close to the inferior vena cava or the main trunk of the hepatic or portal vein, or in the caudate lobe, as well as when the operation is a re‐hepatectomy, because two‐dimensional computed tomography (CT) often does not clearly show tumor location relative to blood vessels.Study DesignTo evaluate the efficacy of three‐dimensional computed tomography (3D‐CT), reconstructed from multidetector‐row computed tomography (MD‐CT) with contrast, MD‐CT was performed in 17 patients before hepatectomy.ResultsThe third‐order branches of the hepatic artery and the portal vein were clearly shown in all cases. Both the hepatic vein, which drained the same segment that the portal vein fed, and the portal vein were also clearly shown. These vessels could be visualized from any perspective. In 2 patients who underwent hemihepatectomy, large tumors (23.0 and 17.0 cm) displaced the vasculature, but the positions of tumor and vessels could be precisely evaluated by 3D‐CT. In patients who required replacement of the vena cava with synthetic grafts, the distance and direction of pressure to IVC by tumor was accurately estimated by 3D‐CT. In patients who were limited to segmentectomy or partial hepatectomy because of prior hepatectomy or tumor position, evaluation of the glissons was facilitated by 3D‐CT.ConclusionsThree‐dimensional‐CT was extremely useful for preoperative simulation because it provided important information that could not be obtained with 2D‐CT.