bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chirality sensing of chiral pyrrolidines and piperazines with a liquid crystalline dynamic helical poly(phenylacetylene) bearing ethyl phosphonate pendant groups
Authors: Morimoto Masao , Tamura Kazumi , Nagai Kanji , Yashima Eiji 
Published: February 2010

AbstractStereoregular cis‐transoidal poly(phenylacetylene) bearing a phosphonic acid monoethyl ester as the pendant group (poly‐1‐H) was found to form a preferred‐handed helix upon complexation with various optically active pyrrolidines and piperazines in dilute dimethyl sulfoxide and water, and the complexes exhibited characteristic induced circular dichroisms (ICDs) in the UV‐vis region of the polymer backbone. The Cotton effect signs in water reflect the absolute configuration of the pyrrolidines. The sodium salt of poly‐1‐H (poly‐1‐Na) and poly‐1‐H in the presence of optically active amines formed lyotropic nematic and cholesteric liquid crystalline phases in concentrated water solutions, respectively, indicating the rigid‐rod characteristic of the polymer main chain regardless of the lack of a single‐handed helix, as evidenced by the long persistence length of about 18 nm before and after the preferred‐handed helicity induction in the polymer. X‐ray diffraction of the oriented films of the nematic and cholesteric liquid crystalline polymers exhibited almost the same diffraction pattern, suggesting that both polymers have the same helical structure; dynamically racemic and one‐handed helices, respectively. On the basis of the X‐ray analysis, a possible helical structure of poly‐1 is proposed. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1383–1390, 2010
Effect of pH and generation of dendron on single‐step synthesis of gold nanoparticles using PEGylated polyamidoamine dendron in aqueous medium
Authors: Harada Atsushi , Yuzawa Akihiko , Kato Takeshi , Kojima Chie , Kono Kenji 
Published: February 2010

AbstractThree types of PEGylated polyamidoamine (PAMAM) dendrons were synthesized through PEGylation of primary amines at the periphery of second, third, and fourth generation dendrons. Au(III) precursors and the synthesized PEGylated PAMAM dendrons were mixed at various pHs to evaluate the effect of pH on gold nanoparticle (Au NP) synthesis by monitoring the change in surface plasmon resonance. The Au NP synthesis reaction was controlled by pH through the balance between protonated and deprotonated tertiary amines and the reactivity of Au(III) precursors. By using PEGylated PAMAM dendrons with higher generation, the obtained Au NPs had narrow size distribution with small average size because of the limitation of intermolecular space among PEGylated PAMAM dendrons for the growth to Au NP. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1391–1398, 2010
Interphase development in a three‐component polymer system with asymmetric mobility
Authors: Miguel María de la Paz , Tomba J. Pablo 
Published: February 2010

AbstractWe report a study on the interphase evolution in a system composed by three polymeric components with markedly different mobility distributed between two layers. One of the layers is a low‐Tg blend containing a low molecular weight polystyrene (PS) as a plasticizer (low‐M PS) and PS chains with much higher molecular weight (high‐M PS). The counterpart is a high‐Tg layer composed by polyphenylene oxide. The system was annealed at several temperatures between Tg of the polymer layers and the subsequent interphase development probed by optical sectioning with confocal Raman microspectroscopy. The profiles obtained revealed the existence of two diffusion fronts that advance in opposite directions, both showing a similar response with time and temperature. These fronts act as well‐defined boundaries that structure the interphase into three well‐defined regions with almost constant PS volume fraction. We discuss this particular phenomenology proposing a simple diffusion model that describes the main interphase features. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 627–633, 2010
Crystallinity effect on the gas transport in semicrystalline coextruded films based on linear low density polyethylene
Authors: Compañ Vicente , Del Castillo L. F. , Hernández S. I. , López‐González M. Mar , Riande Evaristo 
Published: February 2010

AbstractThis article describes the diffusion and permeability of oxygen, carbon dioxide, methane, ethane, ethylene, propane, and propylene in 1‐octene based polyethylene of densities 0.94, 0.92, 0.904, and 0.87. The isotherms obtained in the time‐lag experimental device display a diffusion coefficient and permeability behavior similar to that of glassy polymers. We apply the dual model to semicrystalline polymers assuming that Henry's sites are related to the amorphous phase, which decreases when the crystallinity percentage increases. Whereas the interphase of the polymeric matrix and the crystalline phase prevails and acts as Langmuir sites. Their effect is to increase both, the tortuosity of diffusion trajectories and the chain immobilization. We now explain this effect using thermodynamic considerations. In fact, the tortuosity is related to the change in activation entropy, and the chain immobilization to the cohesive energy of the polymeric matrix. In those terms, the diffusion coefficient does not follow the same crystalline percentage dependence than the solubility. According to the previous findings, the solubility changes in proportion to amorphous percentages. Instead, diffusion coefficient has exponential dependence. Furthermore, we show that the permeability changes as a consequence of the modification of diffusion and solubility, according to the product of both quantities. Comparison with previous publication has been included. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 634–642, 2010
The POSS side chain epoxy nanocomposite: Synthesis and thermal properties
Authors: Chiu Yie‐Chan , Riang Linawati , Chou I‐Chen , Ma Chen‐Chi M. , Chiang Chin‐Lung , Yang Cheng‐Chien 
Published: February 2010

AbstractThe IPI‐POSS‐modified epoxy resin (IPEP) was prepared from isocyanato‐propyldinethylsilyl‐isobutyl‐POSS (IPI‐POSS) and diglycidyl ether of bisphenol A epoxy resin. The steric hindrance of the IPEP bulky POSS side chain improved the curing activation energies. The POSS particles sizes were about 2–3 nm and dispersed uniformly. At lower IPEP concentration (POSS < 12 wt %), the glass transition temperatures (Tgs) of the IPEP nanocomposites increased from 118 to 170 °C. The char yield increased from 15 to 20 wt %, and the LOI values increased from 22 to 28. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 643–652, 2010
Chain confinement in polymer nanocomposites and its effect on polymer bulk properties
Authors: Termonia Yves 
Published: February 2010

AbstractThe issue of chain confinement in nanocomposites remains largely unanswered because experimental systems are plagued by additional complicating variables such as particle–polymer interactions and free volume increases brought upon by the addition of the particles. Using computer simulation of high length chain polymers, we show that simple excluded volume interactions between polymer and nanoparticles lead to a wealth of changes in the diffusion coefficient and entanglement density of the chains. This opens up the possibility of using nanoparticles for tuning polymer properties, such as toughness, melt viscosity, and transient rubberlike behavior. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 687–692, 2010
Organoclay/thermotropic liquid crystalline polymer nanocomposites. III. Effects of fully exfoliated organoclay on morphology, thermal, and rheological properties
Authors: Tang Youhong , Gao Ping , Ye Lin , Zhao Chengbi 
Published: February 2010

AbstractA fully exfoliated organoclay in thermotropic liquid crystalline polymer (TLCP) based nanocomposite was prepared by a method combining ultrasonication, centrifugation, solution casting, and heat‐shearing separation. Morphological study showed that the organoclays of 15–25 nm in size dispersed uniformly in TLCP with fully exfoliated structures. The organoclays formed molecular level interactions with TLCP molecules. The interactions did not affect the liquid crystallinity and mesophase structure of TLCP, but they affected the thermal stability and thermal properties of TLCP, increasing the thermal stability and shifting the transition temperatures to the higher ends. Mechanical rheology investigations in the linear viscoelastic region showed that with the exfoliated organoclay in TLCP, more obvious pseudosolidlike behavior appeared in the terminal region. The rigidity of TLCP was enhanced by the presence of the exfoliated organoclay with percolated structures in the TLCP matrix. In steady shear tests, the nanocomposite had the similar shear viscosity and N1 (the first normal stress difference) to those of TLCP in the steady state condition. Percolated structures were easily destroyed by sufficient shear strain and the exfoliated organoclays were oriented along the shear direction, even assisting the neighboring TLCP molecules to align in the flow direction, resulting in a decrease of viscosity and an increase of the N1 slope. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 712–720, 2010
Glycosylation of liver acute‐phase proteins in pancreatic cancer and chronic pancreatitis
Authors: Sarrats Ariadna , Saldova Radka , Pla Eva , Fort Esther , Harvey David J. , Struwe Weston B. , de Llorens Rafael , Rudd Pauline M. , Peracaula Rosa 
Published: February 2010

AbstractPurpose: Glycosylation of acute‐phase proteins (APP), which is partially regulated by cytokines, may be distinct in disease and provide useful tumour markers. Thus, we have examined the glycosylation of major serum APP in pancreatic cancer (PaC), chronic pancreatitis (CP) and control patients.Experimental design: Using a specific anti‐sialyl Lewis X antibody and N‐glycan sequencing, we have determined glycosylation changes on α‐1‐acid glycoprotein (AGP), haptoglobin (HPT), fetuin (FET), α‐1‐antitrypsin (AT) and transferrin (TRF).Results: Increased levels of sialyl Lewis X (SLex) were detected on AGP in advanced PaC and CP and on HPT, FET, AT and TRF in CP. An increase in N‐glycan branching was detected on AGP and HPT in the advanced stage of PaC and CP and on FET and TRF in the CP. A core fucosylated structure was increased on AGP and HPT only in the advanced PaC patients.Conclusions and clinical relevance: Changes in APP SLex and branching are probably associated with an inflammatory response because they were detected in both advanced PaC and CP patients and these conditions give rise to inflammation. On the contrary, the increase in APP core fucosylation could be cancer associated and the presence of this glycoform may give an advantage to the tumour.
Variance‐corrected proportional hazard models for the analysis of multiple failures in personal computers
Authors: Sunethra A. A. , Sooriyarachchi M. R. 
Published: February 2010

AbstractProportional hazard (PH) modeling is widely used in several areas of study to estimate the effect of covariates on event timing. In this paper, this model is explored for the analysis of multiple occurrences of hardware failures in personal computers. Multiple failure events consist of correlated data, and thus the assumption of independence among failure times is violated. This study critically describes a class of models known asvariance‐corrected PH modelsfor modeling multiple failure time data, without assuming independence among failure times. The objective of this study is to determine the effect of the computer brand on event timings of hardware failures and to test whether this effect varies over multiple failure occurrences. This study revealed that the computer brand affects hardware failure event timing and that further, this effect of the brand does not change over the multiple failure occurrences. Copyright © 2010 John Wiley & Sons, Ltd.
Identification of N‐glycans from Ebola virus glycoproteins by matrix‐assisted laser desorption/ionisation time‐of‐flight and negative ion electrospray tandem mass spectrometry
Authors: Ritchie Gayle , Harvey David J. , Stroeher Ute , Feldmann Friederike , Feldmann Heinz , Wahl‐Jensen Victoria , Royle Louise , Dwek Raymond A. , Rudd Pauline M. 
Published: February 2010

AbstractThe larger fragment of the transmembrane glycoprotein (GP1) and the soluble glycoprotein (sGP) of Ebola virus were expressed in human embryonic kidney cells and the secreted products were purified from the supernatant for carbohydrate analysis. The N‐glycans were released with PNGase F from within sodium dodecyl sulphate/polyacrylamide gel electrophoresis (SDS‐PAGE) gels. Identification of the glycans was made with normal‐phase high‐performance liquid chromatography (HPLC), matrix‐assisted laser desorption/ionisation mass spectrometry, negative ion electrospray ionisation fragmentation mass spectrometry and exoglycosidase digestion. Most glycans were complex bi‐, tri‐ and tetra‐antennary compounds with reduced amounts of galactose. No bisected compounds were detected. Triantennary glycans were branched on the 6‐antenna; fucose was attached to the core GlcNAc residue. Sialylated glycans were present on sGP but were largely absent from GP1, the larger fragment of the transmembrane glycoprotein. Consistent with this was the generally higher level of processing of carbohydrates found on sGP as evidenced by a higher percentage of galactose and lower levels of high‐mannose glycans than were found on GP1. These results confirm and expand previous findings on partial characterisation of the Ebola virus transmembrane glycoprotein. They represent the first detailed data on carbohydrate structures of the Ebola virus sGP. Copyright © 2010 John Wiley & Sons, Ltd.
Effects of water velocity and turbulence on the behaviour of Iberian barbel (Luciobarbus bocagei, Steindachner 1864) in an experimental pool‐type fishway
Authors: Silva Ana T. , Santos José M. , Ferreira Maria T. , Pinheiro António N. , Katopodis Christos 
Published: February 2010

AbstractThe restoration of fish passage has been focused on anadromous fish species, whilst studies accommodating passage of coarse species have often been considered incidental, yet frequently these are the predominant group of species encountered in rivers. In addition, fishway designs depend greatly on the interplay between hydraulics and biomechanics, yet very little data are available on the responses to specific hydraulic settings for these species. This study aims to explore the effects of water velocity and turbulence on the behaviour of a cyprinid species ‐ the Iberian barbel Luciobarbus bocagei (Steindachner, 1864) ‐ particularly their upstream movements upon different discharges (38.5 to 77.0 L · s−1), through an indoor full scale pool‐type fishway prototype. Larger adults had a higher passage success (mean = 79%) and took less time (mean ± SD (min): 5.7 ± 1.3) to negotiate the entire six pool fishway, when compared to small adults. Correlation analysis between hydraulic variables and fish transit time yielded different results. Correlations were found to be the highest between the horizontal component of Reynolds shear stress and fish transit time, particularly for smaller size‐individuals (r = −0.45; p < 0.001), highlighting this variable as a key‐parameter which strongly determines the movements of Iberian barbel. The present study identified key factors on Iberian barbel movements that may have direct application to future fishway designs for this species and for other ‘weak’ swimmers. Copyright © 2010 John Wiley & Sons, Ltd.
Obstetric morbidity associated with amniotic sheets
Authors: Nelson L. D. , Grobman W. A. 
Published: February 2010

AbstractObjectiveThe objective of this study was to determine whether amniotic sheets are associated with an increase in obstetric and neonatal morbidity.MethodsUsing a cohort study design, we identified all women with amniotic sheets, detected by a second‐trimester ultrasound examination at a university hospital over a 6‐year period. All women who received an ultrasound examination during that time, without a diagnosis of amniotic sheets, were also identified, and two women from among this group were randomly selected as controls for each case. Maternal and neonatal data were abstracted from the medical records, and maternal and neonatal morbidity were compared between the two groups.ResultsOne hundred and twenty‐two women with pregnancies with a diagnosis of amniotic sheets were identified and compared to 244 women with pregnancies without a diagnosis of amniotic sheets. Composite obstetric morbidity was higher in women with amniotic sheets: 21.3% vs. 8.2% (relative risk (RR) 2.6; 95% CI, 1.5–4.5). Additionally, in women with amniotic sheets, neonates were more likely to be born with a birth weight of < 2500 g (RR 3.3; 95% CI, 1.8–6.4) and were more likely to be admitted to the neonatal intensive care unit (RR 2.3; 95% CI, 1.3–4.3). There were no perinatal deaths observed in either group.ConclusionAmniotic sheets are associated with an increase in adverse obstetric outcomes. Copyright © 2010 ISUOG. Published by John Wiley & Sons, Ltd.
Can adverse neonatal outcome be predicted in late preterm or term fetal growth restriction?
Authors: Vergani P. , Roncaglia N. , Ghidini A. , Crippa I. , Cameroni I. , Orsenigo F. , Pezzullo J. 
Published: February 2010

AbstractObjectiveTo identify independent predictors of adverse neonatal outcome in cases of fetal growth restriction (FGR) at ≥ 34 weeks.MethodsFrom a cohort of 481 FGR cases delivered at ≥ 34 weeks, demographic and obstetric variables, fetal biometry and Doppler indices of the uterine, umbilical and fetal middle cerebral arteries available within 2 weeks of delivery, were related to adverse neonatal outcome, defined as admission to the neonatal intensive care unit for indications other than low birth weight alone.ResultsLogistic regression analysis showed that gestational age (GA) at delivery (odds ratio (OR) = 0.59; 95% CI, 0.50–0.70), abdominal circumference (AC) centile (OR = 0.69; 95% CI, 0.59–0.81) and umbilical artery (UA) pulsatility index (PI) centile (OR = 1.02; 95% CI, 1.01–1.04) significantly correlated with adverse neonatal outcome. From this model we calculated a score of adverse neonatal outcome expressed by the formula: (UA‐PI centile/3) − (10 × AC centile) + (10 × (40 − GA at delivery in weeks)). Receiver–operating characteristics curve analysis demonstrated that a score of ≥ 25 optimally predicted adverse neonatal outcome (sensitivity of 75%, false‐positive rate of 18%). Beyond 37.5 weeks, gestational age no longer had an independent impact on outcome.ConclusionsIn late preterm or term FGR, GA at delivery is the most important predictor of adverse neonatal outcome. At > 37.5 weeks, delivery may be the best option to minimize adverse outcome in all FGR cases. At 34–37 weeks, a score based on GA at delivery, UA‐PI centile and AC centile optimally predicts adverse neonatal outcome. Copyright © 2010 ISUOG. Published by John Wiley & Sons, Ltd.
Removal of Autografted Parathyroid Tissue for Recurrent Renal Hyperparathyroidism in Hemodialysis Patients
Authors: Tominaga Yoshihiro , Matsuoka Susumu , Uno Nobuaki , Tsuzuki Toyonori , Hiramitsu Takahisa , Goto Norihiko , Nagasaka Takaharu , Watarai Yoshihiko , Uchida Kazuharu 
Published: February 2010

AbstractBackgroundRecurrent renal hyperparathyroidism (HPT) is a serious problem after parathyroidectomy (PTx). We evaluated the frequency of graft‐dependent recurrent HPT and the clinical outcomes after removal of the autograft.MethodsBetween March 1980 and January 2009, 2660 patients underwent total PTx with forearm autograft. After resection of all parathyroid glands, 30 pieces of 1 × 1 × 3 mm parathyroid tissue from diffuse hyperplasia, if possible, were autografted into brachioradial muscle. Graft‐dependent recurrence of HPT was diagnosed by a high PTH gradient and detection of swollen autografts by palpation and/or MRI or US.ResultsIn 248/2660 (9.3%) patients, removal of the graft was required a total of 327 times (53 patients required removal of the autograft several times). The cumulative frequency of graft‐dependent recurrent HPT was 17.4% ten years after the initial PTx. Thirty‐two patients underwent both resection of missed glands located in the neck or mediastinum and removal of the graft. En‐bloc resection of autograft with surrounding muscle was required to avoid reoperation. When the intact PTH level dropped under 300 pg/ml, in the majority of patients renal HPT could be medically managed after the operation. The mean weight of the resected parathyroid tissue was 1583.7 mg. No specimen had histopathologically malignant features. Three patients suffered from hematoma in the wound.ConclusionsGraft‐dependent recurrent renal HPT is not negligible. However, in the majority of patients, renal HPT can be controlled by removal of the autograft noninvasively. Total PTx with forearm autograft is preferable for hemodialysis patients, especially when long‐term survival is expected.
Enhanced Intracellular Heat Shock Protein 70 Expression of Leukocytes and Serum Interleukins Release: Comparison of On‐pump and Off‐pump Coronary Artery Surgery
Authors: Lin Chih‐Yuan , Yang Tung‐Lin , Hong Gou‐Jieng , Li Chi‐Yuan , Lin Feng‐Yen , Tsai Chien‐Sung 
Published: February 2010

AbstractBackgroundCoronary artery bypass grafting (CABG) employing cardiopulmonary bypass (CPB; “on‐pump” technique) is known to induce a systemic inflammatory response and heat‐shock protein 70 kDa (HSP70) expression. The objective of the present study was to investigate the perioperative intracellular HSP70 expression of leukocytes and serum interleukin (IL) release in CABG conducted with both on‐pump and off‐pump techniques.MethodsThirty‐seven patients referred for elective CABG were enrolled in this study. These patients were categorized into the following three groups: on‐pump cardioplegic arrest (n = 12); on‐pump beating heart (n = 13); and off‐pump (n = 12). Blood samples were collected at four time points during the perioperative period. Enzyme‐linked immunosorbent assay (ELISA) was used to determine the serum level of IL‐8, IL‐10, IL‐12, and HSP70. Flow cytometric analysis of intracellular HSP70 was performed in populations of lymphocytes, monocytes, and granulocytes.ResultsThe clinical outcomes were comparable among the three groups. Elevated serum IL‐8, IL‐10, IL‐12 were found in all three groups during the perioperative period. Serum HSP70 was elevated in all three groups and was significantly lower in the off‐pump group than in the on‐pump cardioplegic arrest and on‐pump beating‐heart groups. Heat shock protein‐70 expression was found in leukocytes and showed a faster response in monocytes and granulocytes than in lymphocytes. The inflammatory response in the off‐pump group was less than in either of the on‐pump groups.ConclusionsDuring the perioperative period, activation of inflammatory response was associated with enhanced expression of HSP70 within leukocytes in CABG patients.