bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functionalization of nanoclays with ionic liquids for polypropylene composites
Authors: Ha Jin Uk , Xanthos Marino 
Published: June 2008

AbstractCationic nanoclays were treated by ion exchange with various ionic liquids (ILs) containing cations and anions of different structure and/or molecular weight in order to investigate the effects of the IL structure and cation chain length on extent of clay dispersion, intercalation, and thermal stability. The modified clays containing imidazolium‐, pyridinium‐, and phosphonium‐based cations were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, and X‐ray diffraction. Although the thermal stability of pure ILs was mostly controlled by the type of the anion present, high temperature thermal stability of the modified clays, at the IL cation loadings achieved in this work, was not significantly dependent on type, structure, or size of the cation. The latter parameters, however, were of significant importance in controlling degree of dispersion of the nanoclays during melt compounding with polypropylene (PP). Basal spacing increased proportionally to the size and type of the intercalated cations and showed little change in the PP composites. Although commercial organoclays were shown to be less thermally stable than IL modified clays, they exhibited larger basal spacing and better dispersion characteristics in the polyolefin matrix; however, they increased to the same extent the thermal stability of the PP matrix as the phosphonium modified clays. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Low profile unsaturated polyester resin–clay nanocomposite properties
Authors: Beheshty Mohammad Hosain , Vafayan Mehdy , Poorabdollah Mehdi 
Published: June 2008

AbstractUnsaturated polyester (UP)/organically modified clay (OMC) nanocomposites were prepared by multistep simultaneous mixing of UP oligomer chain, styrene (St) monomer, and OMC. X‐ray diffraction, transmission electron microscopy, dynamic mechanical thermal analysis, and scanning electron microscopy data were in support of the formation of a partially intercalated nanocomposite. The glass transition temperatures of the nanocomposites revealed that the crosslinking reaction occurred homogeneously inside and outside of the OMC galleries. Adding 3 wt% OMC improved the flextural and storage modulus of UP by 31.5% and 30.2%, respectively. The Izod impact strength of UP was also improved by 51.7% at 1 wt% of OMC loading. Similar results were obtained for low‐profile UP/St/OMC nanocomposites. Resin shrinkage data measured by inhouse constructed apparatus showed that, at an OMC content of 3 wt%, the UP/St/OMC/low profile additive (LPA) system cannot provide superior volume shrinkage control. But, it is found that the use of nanoscale reinforcement in the UP systems is able to restore flextural and storage moduli loss when using LPAs. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Is the failing heart out of fuel or a worn engine running rich? A study of mitochondria in old spontaneously hypertensive rats
Authors: Jüllig Mia , Hickey Anthony J. R. , Chai Chau C. , Skea Gretchen L. , Middleditch Martin J. , Costa Silvana , Choong Soon Y. , Philips Anthony R. J. , Cooper Garth J. S. 
Published: June 2008

AbstractHypertension now affects about 600 million people worldwide and is a leading cause of death in the Western world. The spontaneously hypertensive rat (SHR), provides a useful model to investigate hypertensive heart failure (HF). The SHR model replicates the clinical progression of hypertension in humans, wherein early development of hypertension is followed by a long stable period of compensated cardiac hypertrophy that slowly progresses to HF. Although the hypertensive failing heart generally shows increased substrate preference towards glucose and impaired mitochondrial function, the cause‐and‐effect relationship between these characteristics is incompletely understood. To explore these pathogenic processes, we compared cardiac mitochondrial proteomes of 20‐month‐old SHR and Wistar‐Kyoto controls by iTRAQ™‐labelling combined with multidimensional LC/MS/MS. Of 137 high‐scoring proteins identified, 79 differed between groups. Changes were apparent in several metabolic pathways, chaperone and antioxidant systems, and multiple subunits of the oxidative phosphorylation complexes were increased (complexes I, III and IV) or decreased (complexes II and V) in SHR heart mitochondria. Respiration assays on skinned fibres and isolated mitochondria showed markedly lower respiratory capacity on succinate. Enzyme activity assays often also showed mismatches between increased protein expression and activities suggesting elevated protein expression may be compensatory in the face of pathological stress.
Proteomic analysis of an imatinib‐resistant K562 cell line highlights opposing roles of heat shock cognate 70 and heat shock 70 proteins in resistance
Authors: Pocaly Marion , Lagarde Valérie , Etienne Gabriel , Dupouy Maryse , Lapaillerie Delphine , Claverol Stéphane , Vilain Sébastien , Bonneu Marc , Turcq Béatrice , Mahon François‐Xavier , Pasquet Jean‐Max 
Published: June 2008

AbstractUnderstanding the molecular basis of resistance to imatinib, a tyrosine kinase inhibitor used as front‐line therapy in chronic myeloid leukemia, remains a challenge for successful treatment. In an attempt to identify new mechanisms of resistance, we performed a comparative proteomic analysis of an imatinib‐resistant cell line generated from the erythroblastic cell line K562 (K562‐r) for which no known mechanism of resistance has been detected. Bidimensional gel electrophoresis was carried out to compare the protein expression pattern of imatinib‐sensitive and of imatinib‐resistant K562 cells. Among the 400 matched spots on five pairs of gels, only 14 spots had a significantly increased or decreased expression leading to the identification of 24 proteins identified as scaffold proteins, metabolic enzymes, DNA translation and maturation, and chaperon proteins. Among the chaperon family, only Hsp70 and Hsc70 are overexpressed in K562‐r, results confirmed by Western blotting. We recently reported the participation of Hsp70 overexpression in imatinib resistance whereas a role for Hsc70 has yet to be determined. Hsc70 is not involved in imatinib resistance as the inhibition of its expression by siRNA does not restore sensitivity to imatinib. In contrast, the induced decreased expression of Hsc70 was accompanied by a greater overexpression of Hsp70. This proteomic study therefore suggests opposing roles of Hsp70 and Hsc70 in imatinib resistance.
Polymerization and nanocomposites properties of multifunctional methylmethacrylate POSS
Authors: Liu Ying‐Ling , Tseng Min‐Chi , Fangchiang Meng‐Han 
Published: June 2008

AbstractThermally induced polymerization of multifunctional methylmethacrylate POSS (MMA‐POSS) was studied in this work for preparation of polymer/POSS nanocomposites. The polymerization of MMA‐POSS could be promoted with benzoyl peroxide (BPO). Self‐assembly of POSS into a layer‐by‐layer structure in the MMA‐POSS polymer (TP‐MMA‐POSS) is observed with a transmission electron microscopy. An ultra‐low‐k value of about 1.85 is measured with TP‐MMA‐POSS. In addition, polyimide‐POSS nanocomposites are also prepared. These nanocomposites demonstrate good homogeneity and enhanced mechanical properties. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5157–5166, 2008
“Push‐pull” supramolecular chromophores supported on cyclopolymers
Authors: Coluccini Carmine , Metrangolo Pierangelo , Parachini Marco , Pasini Dario , Resnati Giuseppe , Righetti Pierpaolo 
Published: June 2008

AbstractWell‐defined macromolecules have been obtained through free‐radical cyclopolymerization and cyclocopolymerization of difunctional and acrylic‐like monomers, which contained “push‐pull” supramolecular chromophores, able to form 1:1 complexes with Eu3+ ions in solution. The monomeric molecular modules are built around bismalonate crown ethers in a convergent fashion, in which one of the malonate moiety is derivatized as the ylidene malonate push‐pull fragment, and the other malonate moiety is elaborated to introduce two polymerizable and acrylic‐like substituents. The free‐radical induced cyclopolymerization of these monomers, or their cyclocopolymerization with UV/Vis “silent” but structurally related monomers, afforded macromolecular architectures characterized by GPC, NMR and DSC techniques. UV/Vis titration studies, performed with Eu(OTf)3 as the supramolecular probe, revealed how adjacent chromophores within the polymeric backbone are virtually independent from each other, and how the binding ability towards the probe of these multivalent, highly packed cyclopolymeric architectures, although reduced, is still clearly detectable. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5202–5213, 2008
Proteomic analysis of altered proteins in distal renal tubular cells in response to calcium oxalate monohydrate crystal adhesion: Implications for kidney stone disease
Authors: Semangoen Theptida , Sinchaikul Supachok , Chen Shui‐Tein , Thongboonkerd Visith 
Published: June 2008

AbstractAdhesion of calcium oxalate (CaOx) crystals to renal tubular cells is a critical event that triggers a cascade of responses, leading to the development of kidney stones. However, the molecular mechanisms of these cellular responses remain largely unknown. We performed gel‐based, differential proteomics study to examine cellular responses (as determined by altered protein expression) in Madin–Darby Canine Kidney (MDCK) cells during CaOx monohydrate (COM) crystal adhesion. Approximately 3‐million MDCK cells were inoculated in each culture flask and maintained for 24 h. A total of 10 semiconfluent flasks were then divided into two groups (n = 5 per group) and the culture medium was replaced by either COM‐containing (with 100 μg/mL COM crystals) or COM‐free medium. The cells were grown further for 48 h. Crystal adhesion on the cell surface was clearly demonstrated using phase‐contrast and scanning electron microscopy. Cell death assay using annexin V/propidium iodide double staining showed that all these samples had comparable % cell death. Cellular proteins were then extracted, resolved with 2‐DE, and visualized by SYPRO Ruby staining (n = 5 gels per group). Quantitative intensity analysis revealed significantly increased abundance of 15 protein spots, whereas the other 5 were decreased. These altered proteins were then identified by quadrupole TOF (Q‐TOF) MS and/or MS/MS analyses, including transcription/translation regulators, signal transduction proteins, metabolic enzymes, nuclear membrane proteins, carrier protein, cellular structural protein, chaperones, and proteins involved in biosynthesis, enzyme activation, and growth regulation. These data may lead to better understanding of the cellular responses in distal renal tubular cells during COM crystal adhesion.
Proteomic analysis of human proximal tubular cells exposed to high glucose concentrations
Authors: So Eun‐Jeong , Kim Hyun‐Jung , Kim Chan‐Wha 
Published: June 2008

AbstractHyperglycemia is a major key factor in the pathogenesis of microvascular complications of diabetes, including diabetic nephropathy (DN). Most studies to date have focused on the glomerular abnormalities found in DN. However, nephromegaly in the early stages of diabetes and the correlation of tubulointerstitial pathology rather than glomerular pathology with declining renal function in DN suggests the involvement of the tubulointerstitium. The etiology of the tubulointerstitial pathology in DN, however, is not fully understood. In this study, to understand the DN pathways, we constructed an initial 2‐DE reference map for primitively cultured human proximal tubule (HK‐2) cell in the presence of 5 mM and 25 mM glucose, which correspond to blood glucose concentrations during the normal and hyperglycemia conditions, respectively. Differentially expressed HK‐2 cell cellular proteins at the high glucose concentration were identified via ESI‐Q‐TOF MS/MS and confirmed by Western blotting; enolase 1 (up‐regulated) and lactate dehydrogenase (down‐regulated). The regulation of these proteins will help in understanding DN mechanism through the glycolysis metabolic pathways in high glucose stimulated HK‐2 cells.
Optical absorption in ZrO2–x‐C nanocomposite films on polymer substrates: application of an effective medium theory
Authors: Cheyssac P. , Laidani N. , Anderle M. 
Published: June 2008

AbstractRF sputtering from separate zirconia and graphite targets enables room‐temperature co‐deposition of ZrO2–x and carbon onto polycarbonate substrates. Films consist of amorphous carbon dispersed in tetragonal nanocrystalline zirconia; their optical properties have been determined by reflectance measurements at normal incidence and over the visible range. The optical constants of each component of the composite have been extracted; the experimental reflectance spectra have been fitted to Maxwell‐Garnett effective medium theory, leading to the effective dielectric constants of the film. Absorption is characterized by the band gap, the energy and lifetime of the optical transition of the absorbing carbon phase. These parameters are deduced from the imaginary part of the dielectric function using Tauc‐Lorentz model (TL) and from the extinction coefficient using Forouhi‐Bloomer model (FB) in which an energy dependence of the matrix element of the transition has been introduced. Furthermore, the energies of the peak transition and the maximum of the extinction coefficient are so similar that they prove the self‐consistency of the modified‐FB model applied to the amorphous carbon phase of the composite films. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effects of variation in streamflow and channel structure on smallmouth bass habitat in an alluvial stream
Authors: Remshardt W. Jason , Fisher William L. 
Published: June 2008

AbstractWe evaluated the effects of streamflow‐related changes in channel shape and morphology on the quality, quantity, availability and spatial distribution of young‐of‐year and adult smallmouth bass Micropterus dolomieu habitat in an alluvial stream, the Baron Fork of the Illinois River, Oklahoma. We developed Habitat Suitability Criteria (HSC) for young‐of‐year and adult smallmouth bass to assess changes in available smallmouth bass habitat between years, and compare predicted smallmouth bass Weighted Usable Area (WUA) with observed WUA measured the following year. Following flood events between 1999 and 2000, including a record flood, changes in transect cross‐sectional area ranged from 62.5% to 93.5% and channel mesohabitat overlap ranged from 29.5% to 67.0% in study three study reaches. Using Physical HABitat SIMulation (PHABSIM) system analysis, we found that both young‐of‐year and adult smallmouth bass habitat were differentially affected by intra‐ and inter‐annual streamflow fluctuations. Maximum WUA for young‐of‐year and adults occurred at streamflows of 1.8 and 2.3 m3 s−1, respectively, and WUA declined sharply for both groups at lower streamflows. For most microhabitat variables, habitat availability was similar between years. Habitat suitability criteria developed in 1999 corresponded well with observed fish locations in 2000 for adult smallmouth bass but not for young‐of‐year fish. Our findings suggest that annual variation in habitat availability affects the predictive ability of habitat models for young‐of‐year smallmouth bass more than for adult smallmouth bass. Furthermore, our results showed that despite the dynamic nature of the gravel‐dominated, alluvial Baron Fork, HSC for smallmouth bass were consistent and transferable between years. Published in 2008 by John Wiley & Sons, Ltd.
Summarizing differences in cumulative incidence functions
Authors: Zhang Mei‐Jie , Fine Jason 
Published: June 2008

AbstractThe cumulative incidence function is widely reported in competing risks studies, with group differences assessed by an extension of the log‐rank test. However, simple, interpretable summaries of group differences are not available. An adaptation of the proportional hazards model to the cumulative incidence function is often employed, but the interpretation of the hazard ratio may be somewhat awkward, unlike the usual survival set‐up. We propose nonparametric inferences for general summary measures, which may be time‐varying, and for time‐averaged versions of the measures. Theoretical justification is provided using counting process techniques. A real data example illustrates the practical utility of the methods. Copyright © 2008 John Wiley & Sons, Ltd.
Endopolyploidy in irradiated p53‐deficient tumour cell lines: Persistence of cell division activity in giant cells expressing Aurora‐B kinase
Authors: Erenpreisa Jekaterina , Ivanov Andrei , Wheatley Sally P. , Kosmacek Elizabeth A. , Ianzini Fiorenza , Anisimov Alim P. , Mackey Michael , Davis Paul J. , Plakhins Grigorijs , Illidge Timothy M. 
Published: June 2008

AbstractRecent findings including computerised live imaging suggest that polyploidy cells transiently emerging after severe genotoxic stress (and named ‘endopolyploid cells’) may have a role in tumour regrowth after anti‐cancer treatment. Until now, mostly the factors enabling metaphase were studied in them. Here we investigate the mitotic activities and the role of Aurora‐B, in view of potential depolyploidisation of these cells, because Aurora‐B kinase is responsible for coordination and completion of mitosis. We observed that endopolyploid giant cells are formed via different means in irradiated p53 tumours, by: (1) division/fusion of daughter cells creating early multi‐nucleated cells; (2) asynchronous division/fusion of sub‐nuclei of these multi‐nucleated cells; (3) a series of polyploidising mitoses reverting replicative interphase from aborted metaphase and forming giant cells with a single nucleus; (4) micronucleation of arrested metaphases enclosing genome fragments; or (5) incomplete division in the multi‐polar mitoses forming late multi‐nucleated giant cells. We also observed that these activities can release para‐diploid cells, although infrequently. While apoptosis typically occurs after a substantial delay in these cells, we also found that ∼2% of the endopolyploid cells evade apoptosis and senescence arrest and continue some form of mitotic activity. We describe here that catalytically active Aurora‐B kinase is expressed in the nuclei of many endopolyploid cells in interphase, as well as being present at the centromeres, mitotic spindle and cleavage furrow during their attempted mitotes. The totally micronucleated giant cells (containing sub‐genomic fragments in multiple micronuclei) represented only the minor fraction which failed to undergo mitosis, and Aurora‐B was absent from it. These observations suggest that most endopolyploid tumour cells are not reproductively inert and that Aurora‐B may contribute to the establishment of resistant tumours post‐irradiation.
Percutaneous coronary intervention for acute MI does not prevent in‐hospital development of cardiogenic shock compared to fibrinolysis
Authors: Lindholm Matias G. , Boesgaard Søren , Thune Jens Jakob , Kelbaek Henning , Andersen Henning Rud , Kober Lars ,   DANAMI‐2 investigators
Published: June 2008

AbstractBackground:It has been speculated that invasive revascularization prevents development of cardiogenic shock. Data from randomised trials comparing angioplasty with fibrinolysis on the development of cardiogenic shock are lacking.Aims:To elucidate the effect of angioplasty on in‐hospital development of cardiogenic shock compared to fibrinolysis.To evaluate whether mortality in patients who develop cardiogenic shock after treatment is dependent on revascularization strategy.Methods and results:DANAMI‐2 randomly assigned 1572 STEMI patients to fibrinolysis (782 patients) or angioplasty (790 patients). Data on patients with in‐hospital development of cardiogenic shock after randomisation were included. Of the 103 patients (6.6%) patients developing cardiogenic shock 57% were randomised to angioplasty with an unadjusted odds ratio of 1.39 (0.92–2.11, p=0.14). During the three year follow‐up 58% of the total mortality was due to cardiogenic shock, and treatment strategy did not influence the risk associated with shock (hazard ratio of 1.05 (0.67–1.64) for angioplasty vs. fibrinolysis).Conclusions:Angioplasty does not prevent the in‐hospital development of cardiogenic shock complicating acute MI compared to fibrinolysis. Cardiogenic shock is still the leading cause of death in patients hospitalised for acute MI. There was no difference in mortality, with regards to treatment strategy in patients developing cardiogenic shock after the initial treatment.
Reduced in vivo skeletal muscle oxygen consumption in patients with chronic heart failure—A study using Near Infrared Spectrophotometry (NIRS)
Authors: Abozguia Khalid , Phan Thanh Trung , Shivu Ganesh Nallur , Maher Abdul R. , Ahmed Ibrar , Wagenmakers Anton , Frenneaux Michael P. 
Published: June 2008

AbstractAim:We used Near Infrared Spectrophotometry (NIRS) during arterial occlusion to measure resting skeletal muscle oxygen consumption in chronic heart failure (CHF) patients and in age‐matched healthy volunteers (HVs).Methods:Fifteen CHF patients (ten males) and eleven HVs (six males) had echocardiographic evaluation followed by measurement of the oxygen consumption of the brachioradialis muscle using NIRS. This involved continuous measurement of the oxygenated haemoglobin concentration ([Oxy‐Hb]) and deoxy‐haemoglobin concentration ([Deoxy‐Hb]) with an Oxiplex TS NIRS probe first under basal overnight fasted resting conditions followed by 1 min of forearm arterial occlusion. A linear decline was observed in [Oxy‐Hb–Deoxy‐Hb] during the arterial occlusion and the oxygen consumption rate was calculated from the initial slope observed.Results:CHF patients were 59±2.8 years old with Left Ventricular Ejection Fraction (LVEF) 31%±2.2 and the HVs were 52±4.8 years old with LVEF 62%±2.5. The resting muscle oxygen consumption rate was significantly reduced in CHF patients versus HVs (0.04±0.01 mlO2/min/100 g versus 0.07±0.01 mlO2/min/100 g) p<0.005.Conclusions:There is a significant reduction in resting oxygen consumption per gram of tissue in skeletal muscle of patients with CHF.
Facilitated neurotrophin release in sensitized human skin
Authors: Paterson Sarah , Schmelz Martin , McGlone Francis , Turner Graham , Rukwied Roman 
Published: June 2008

ABSTRACTThe neurotrophins nerve growth factor (NGF) and brain‐derived neurotrophic factor (BDNF) play a pivotal role in the generation and maintenance of hyperalgesia.In the present study we analyzed NGF and BDNF levels in human skin of the upper arm and axilla skin sites by dermal microdialysis and multiplexed assay. Skin sensitization and inflammatory responses were evoked experimentally by repetitive shaving of one axilla provoking local erythema and reduced heat pain thresholds. Acute excitation of skin nociceptors was performed by perfusion of the microdialysis catheters with citric acid pH 3. At baseline, neurotrophin concentrations did not differ significantly between the investigated skin sites. On average, NGF concentration was 5.8fg/μg protein/ml sample volume and BDNF concentration was 87.5fg/μg/ml. Citric acid perfusion marginally increased NGF levels to 7.3fg/μg/ml on average in the upper arm and control axilla. Similarly, BDNF values increased at these control skin sites to about 122fg/μg/ml following proton stimulation. In contrast, perfusion of the inflamed axilla with citric acid significantly enhanced the release of both NGF and BDNF. On average, NGF levels were analyzed at 14.6fg/μg/ml and BDNF values at 202fg/μg/ml. These data demonstrate enhanced level of neurotrophin release in inflamed human skinin vivowhich might well contribute to peripheral sensitization. Analyses of neurotrophic factors by dermal microdialysis are useful endogenous markers to further explore their role in neuronal sensitization processes in human.