bluuebunny/crossref_metadata_2025_split huggingface dataset:
PtCo/Polypyrrole‐Multiwalled Carbon Nanotube Complex Cathode Catalyst Containing Two Types of Oxygen Reduction Active Sites Used in Direct Methanol Fuel Cells
Authors: Zhao H. , Pan L. , Jin J. , Li L. , Xu J. 
Published: September 2012

AbstractLow oxygen reduction reaction (ORR) activity and high cost of noble metal catalysts are two major challenges in direct methanol fuel cells (DMFCs). Pt‐based catalysts are considered as an ideal alternative to deal with these two problems. While the second component metals play only the role of synergy effect with Pt, they themselves are inert towards activity towards ORR. It is necessary to design a new route to ultilize the second component metal by forming CoNx ORR active site on the base of PtM catalyst. In this paper, PtCo/polypyrrole‐multiwalled carbon nanotubes (PtCo/PPy‐MWCNTs) catalyst containing two types of ORR active site (Pt and CoNx) was synthesized by one pot synthesis route. The effect and dynamic mechanism of the named CoNx active site towards ORR was discussed by X‐ray photoelectron sprectroscopy and linear sweep voltammetry. PtCo/PPy‐MWCNTs cathode catalyst showed improved activity towards ORR and great potential in DMFCs.
Microstructural Analysis of Interfaces between Lanthanum Contained Glass and Two Different Electrolytes for SOFC Applications
Authors: Kaur G. , Pandey O. P. , Singh K. 
Published: September 2012

AbstractThe diffusion couples of lanthanum based strontium borosilicate glass with two different (high and low temperature) electrolytes have been heat‐treated at 850 and 800 °C, respectively, for 5, 100, and 750 h to understand the mechanism of interface formation and growth. These prepared diffusion couples have been characterized using various techniques like X‐ray diffraction (XRD), scanning electron microscope (SEM), X‐ray dot mapping, and electron probe microanalysis (EPMA). XRD revealed no detrimental phase formation. Other thermodynamic parameters like frequency factor, crystallization constants, free volume, and bulk thermal expansion coefficients have been calculated to understand the behavior of glass under the influence of temperature. These theoretical parameters will enable to understand the interfacial growth observed in heat‐treated couple for its end application in SOFC. The observed results indicate that lanthanum containing glass exhibit stable and smooth interface with yttria‐stabilized zirconia (high‐temperature electrolyte) as compared to doped bismuth vanadate (low temperature electrolyte).
t(11;14)(q23;q32) involving IGH and DDX6 in nodal marginal zone lymphoma
Authors: Stary Susanne , Vinatzer Ursula , Müllauer Leonhard , Raderer Markus , Birner Peter , Streubel Berthold 
Published: September 2012

AbstractNodal marginal zone lymphoma (NMZL) is a primary nodal B‐cell lymphoma that shares morphological and immunophenotypic characteristics with extranodal and splenic marginal zone lymphoma. Data on altered genes and signaling pathways are scarce in this rare tumor entity. To gain further insights into the genetic background of NMZL, seven cases were investigated by microarray analysis, G‐banding, and FISH. Chromosomal imbalances were observed in 3/7 cases (43%) with gains of chromosome arms 1q, 8q, and 12q being the most frequent findings. Furthermore, we identified a translocation t(11;14)(q23;q32) involving IGH and DDX6. Chromosomal walking, expression analysis, siRNA‐mediated gene knockdown and a yeast two hybrid screen were performed for further characterization of the translocation in vitro. In siRNA experiments, DDX6 appeared not to be involved in NF‐κB activation as frequently observed for genes promoting lymphomagenesis but was found to interfere with the expression of BCL6 and BCL2 in an NF‐κB independent manner. In conclusion, we identified several unbalanced aberrations and a t(11;14) involving IGH and DDX6 providing evidence for a contribution of DDX6 to lymphomagenesis by deregulation of BCL6 in NMZL. © 2012 Wiley Periodicals, Inc.
Expression of the MAP kinase phosphatase DUSP4 is associated with microsatellite instability in colorectal cancer (CRC) and causes increased cell proliferation
Authors: Gröschl Benedikt , Bettstetter Marcus , Giedl Christian , Woenckhaus Matthias , Edmonston Tina , Hofstädter Ferdinand , Dietmaier Wolfgang 
Published: September 2012

AbstractDUSP4 (MKP‐2), a member of the mitogen‐activated protein kinase phosphatase (MKP) family and potential tumor suppressor, negatively regulates the MAPKs (mitogen‐activated protein kinases) ERK, p38 and JNK. MAPKs play a crucial role in cancer development and progression. Previously, using microarray analyses we found a conspicuously frequent overexpression of DUSP4 in colorectal cancer (CRC) with high frequent microsatellite instability (MSI‐H) compared to microsatellite stable (MSS) CRC. Here we studied DUSP4 expression on mRNA level in 38 CRC (19 MSI‐H and 19 MSS) compared to matched normal tissue as well as in CRC cell lines by RT‐qPCR. DUSP4 was overexpressed in all 19 MSI‐H tumors and in 14 MSS tumors. Median expression levels in MSI‐H tumors were significantly higher than in MSS‐tumors (p < 0.001). Consistently, MSI‐H CRC cell lines showed 6.8‐fold higher DUSP4 mRNA levels than MSS cell lines. DUSP4 expression was not regulated by promoter methylation since no methylation was found by quantitative methylation analysis of DUSP4 promoter in CRC cell lines neither in tumor samples. Furthermore, no DUSP4 mutation was found on genomic DNA level in four CRC cell lines. DUSP4 overexpression in CRC cell lines through DUSP4 transfection caused upregulated expression of MAPK targets CDC25A, CCND1, EGR1, FOS, MYC and CDKN1A in HCT116 as well as downregulation of mismatch repair gene MSH2 in SW480. Furthermore, DUSP4 overexpression led to increased proliferation in CRC cell lines. Our findings suggest that DUSP4 acts as an important regulator of cell growth within the MAPK pathway and causes enhanced cell growth in MSI‐H CRC.
Genetic variation in the lactase gene, dairy product intake and risk for prostate cancer in the European prospective investigation into cancer and nutrition
Authors: Travis Ruth C. , Appleby Paul N. , Siddiq Afshan , Allen Naomi E. , Kaaks Rudolf , Canzian Federico , Feller Silke , Tjønneland Anne , Føns Johnsen Nina , Overvad Kim , Ramón Quirós J. , González Carlos A. , Sánchez Maria‐José , Larrañaga Nerea , Chirlaque Maria‐Dolores , Barricarte Aurelio , Khaw Kay‐Tee , Wareham Nick , Trichopoulou Antonia , Valanou Elisavet , Oustoglou Erifili , Palli Domenico , Sieri Sabina , Tumino Rosario , Sacerdote Carlotta , Bueno‐de‐Mesquita H. B(as). , Stattin Pär , Ferrari Pietro , Johansson Mattias , Norat Teresa , Riboli Elio , Key Timothy J 
Published: September 2012

AbstractHigh dairy protein intake has been found to be associated with increased prostate cancer risk in the European Prospective Investigation into Cancer and Nutrition (EPIC). To further examine this possible relationship, we investigated the hypothesis that a genetic polymorphism in the lactase (LCT) gene might be associated with elevated dairy product intake and increased prostate cancer risk in a case–control study nested in EPIC. The C/T‐13910 lactase variant (rs4988235) was genotyped in 630 men with prostate cancer and 873 matched control participants. Dairy product consumption was assessed by diet questionnaire. Odds ratios (ORs) for prostate cancer in relation to lactase genotype were estimated by conditional logistic regression. Lactase genotype frequency varied significantly between countries, with frequencies of the T (lactase persistence) allele ranging from 7% in Greece to 79% in Denmark. Intake of milk and total dairy products varied significantly by lactase genotype after adjustment for recruitment center; adjusted mean intakes of milk were 44.4, 69.8 and 82.3 g/day among men with CC, CT and TT genotypes, respectively. The lactase variant was not significantly associated with prostate cancer risk, both in our data (adjusted OR for TT vs. CC homozygotes: 1.10, 95% CI: 0.76–1.59) and in a meta‐analysis of all the published data (combined OR for T allele carriers vs. CC homozygotes: 1.12, 0.96–1.32). These findings show that while variation in the lactase gene is associated with milk intake in men, the lactase polymorphism does not have a large effect on prostate cancer risk.
Pharmacological validation of early and late phase of rat mono‐iodoacetate model using the Tekscan system
Authors: Rashid M.H. , Theberge Y. , Elmes S.J. , Perkins M.N. , McIntosh F. 
Published: September 2012

AbstractBackgroundPrevious pharmacological validations of the rat mono‐iodoacetate (MIA)‐induced chronic joint pain model were mostly performed by measuring weight‐bearing (WB) deficit with an incapacitance tester. However, conventional incapacitance testers have several drawbacks including restrain stress on animal and sole use of hind limbs WB.ObjectivesThe aim of the present study was to compare pharmacological sensitivity of the early (up to 1 week after MIA) versus late (between 2 and 4 weeks after MIA) phase of the rat MIA model using a highly sensitive tactile pressure measurement system (Tekscan®), which can measure weight borne by all four limbs and the tail in a non‐restrained animal.MethodsThe Tekscan® WB measurement system was used in MIA rats to examine the acute and chronic dosing effects of drugs that targeted different mechanisms. Electrophysiological recordings from joint afferents and biochemical analysis of synovial fluid were also performed.ResultsDexamethasone, duloxetine and morphine significantly alleviated WB deficits in the Tekscan® system during both early and late phase of the MIA model while celecoxib and naproxen alleviated WB deficit only during the early phase. Similarly, naproxen was able to inhibit spontaneous neuronal activity from MIA joint afferents only during the early phase. Finally, concentrations of prostaglandin E2 in synovial fluid were elevated only during the early phase of the rat MIA model.ConclusionsOur pharmacological validation studies using the Tekscan® system along with electrophysiological and biochemical results suggest different mechanisms for early and late phase of MIA‐induced chronic joint pain in rat.
Diethyl phthalate enhances expression of SIRT1 and DNMT3a during apoptosis in PC12 cells
Authors: Sun Yongkun , Guo Zhikun , Iku Shouhei , Saito Takeshi , Kurasaki Masaaki 
Published: September 2012

ABSTRACTDiethyl phthalate (DEP) works as a phthalate plasticizer and is ubiquitously used in personal care products, cosmetics, medical equipment and pharmaceutical coating. DEP is considered a potential endocrine disruptor. Previously we found DEP‐enhanced apoptosis induced by serum deprivation in PC12 cells. However, the relationship between DEP and longevity‐related factors, sirtuins and epigenetic factors (e.g. DNA methyltransferases) remains unclear, because genome modification caused by chemical toxicity, sirtuins and epigenetic factors have played key roles in abnormal metabolism and development. Here, we investigate whether DEP affects sirtuins (SIRT1 and SIRT2) and methyltranferases (DNMT1 and DNMT3a) on the apoptosis of PC12 cells. We found that DNMT3a was significantly decreased by serum deprivation. However, DNMT3a, DNMT3b and SIRT1 were significantly increased under the enhancement of apoptosis induced by serum deprivation. These results suggest that SIRT1, DNMT3a and DNMT3b play multiple and complex roles in different apoptotic stages. Our results showed DEP triggered epigenetic factors on PC12 cells apoptosis under nutrition stress. Finally, our results suggest that monitoring epigenetic factors such as DNMT3a, DNMT3b and SIRT1 could be a useful tool for chemical toxicity risk assessment. Copyright © 2012 John Wiley & Sons, Ltd.
Phagocytic uptake and ROS‐mediated cytotoxicity in human hepatic cell line of amphiphilic polyphosphazene nanoparticles
Authors: Qiu Liyan , Chen Yue , Gao Menghua , Zheng Cheng , Zhao Qinghe 
Published: September 2012

AbstractThe pH‐responsive amphiphilic polyphosphazenes bearing N,N‐diisopropylethylenediamine (DPA) have been proven to be promising nanovehicles for drug antitumor therapy. To further modify these amphiphilic polyphosphazenes with fluorescent labeling agent or other biochemical functional groups, serine methyl ester containing active chemical group NH2 was chosen to be introduced to get a novel polymer [NP(PEG)0.24(DPA)0.5(SME)1.26]n (PDS‐NH2). Considering the possible toxic effect of NH2 group, the biocompatibility in bloodstream and nanotoxicity on human normal hepatic L‐02 cells was evaluated in this study. The polymer [NP(PEG)0.24(DPA)0.5(SME‐BOC)1.26]n (PDS‐BOC) linked with tert‐butyloxycarbonyl groups to protect and hide NH2 group was applied as the comparison. First, the bovine serum albumin (BSA) adsorption and phagocytic uptake behavior in human THP‐1 macrophages were performed. The results suggested that only a minor percentage of the nanoparticles were involved in BSA binding and phagocytic uptake as the result of PEGylation on the particulate surface. To determine the nanotoxicity on human normal hepatic L‐02 cells, we measured cell viability, apoptosis and necrosis, reactive oxygen species generation, the loss of mitochondrial membrane potential, and the levels of the apoptotic signaling proteins in L‐02 cells after the cells being exposed to nanoparticles of different concentrations (0.1, 0.2, and 0.5 mg/mL) for 24 h. Our data indicated that the two nanoparticles induced cytotoxicity in a dose‐dependent manner; PDS‐NH2 caused more cytotoxicity than PDS‐BOC as a result of NH2 exposure. The increased expression of caspase‐3 and caspase‐9 suggested that they triggered apoptosis through mitochondria‐dependent pathways in L‐02 cells. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 101A:285–297, 2013.
Cell adhesion and osteogenic differentiation on three‐dimensional pillar surfaces
Authors: Kaivosoja Emilia , Suvanto Pia , Barreto Gonçalo , Aura Susanna , Soininen Antti , Franssila Sami , Konttinen Yrjö T. 
Published: September 2012

AbstractWe hypothesized that when compared with conventional two‐dimensional (2D) cultures, substrates containing 3D micropillars would allow cells to grow at levels, activating their cytoskeleton to promote osteogenesis. Fibroblasts, osteoblast‐like cells, and mesenchymal stem cells (MSCs) were studied. Planar substrates were compared with 200‐nm‐, 5‐μm‐, and 20‐μm‐high pillars of Ormocomp®, Si, diamond‐like carbon, or TiO2. Scanning electron microscopy and staining of actin cytoskeleton showed 7.5‐h adhesion to pillar edges and 5‐day stretching between adhesion contacts > 100‐μm distances of fibroblast and MSC in 3D networks, whereas SaOS‐2 cells adhered flatly and individually on horizontal and vertical surfaces. ERK and ROCK immunostaining at 14 and 21 days confirmed activation of the cytoskeleton. In contrast to expectations, success to induce osteogenesis was dominated by the cytocompatibility of the substrate over the 3D structure. This was shown using early alkaline phosphatase, intermediate osteopontin, and late mineralization markers, together with bone nodule formation, which were seen in planar substrates and low‐profile TiO2 pillars, but were poor in the 20‐μm landscape. The lack of intercellular contacts seems to halt the osteogenesis‐promoting effects of cytoskeletal organization and tension described earlier. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 101A: 842–852, 2013.
Novel selenium‐doped hydroxyapatite coatings for biomedical applications
Authors: Rodríguez‐Valencia C. , López‐Álvarez M. , Cochón‐Cores B. , Pereiro I. , Serra J. , González P. 
Published: September 2012

AbstractNowadays there is a short‐term need of investigating in orthopedic implants with a greater functionality, including an improved osseointegration and also antibacterial properties. The coating of metallic implants with hydroxyapatite (HA) remains to be the main proposal, but superior quality HA coatings with compositions closer to natural bone apatites, including carbonates, trace elements are required. Selenium is an essential nutrient in biological tissues and, at the same time, it also presents antibacterial properties. A pioneering study on the fabrication of selenium‐doped carbonated hydroxyapatite (iHA:Se) coatings by Pulsed Laser Deposition (PLD) is presented. Different proportions of selenium were incorporated to obtain the iHA:Se coatings. Their physicochemical characterization, performed by SEM/EDS, FTIR, FT‐Raman, Interferometric Profilometry and XPS, revealed typical columnar growth of HA in globular aggregates and the efficient incorporation of selenium into the HA coatings by the, most probably, substitution of SeO groups in the CO sites. Biological evaluation illustrated the absence of cytotoxicity when an amount of 0.6 at.% of Se was added to the iHA:Se coatings and excellent proliferation of the MC3T3‐E1 preosteoblasts. Antibacterial properties were also proved with the inhibition of P. aeruginosa and S. aureus from establishing bacterial biofilms. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 101A: 853–861, 2013.
Study of the effect of membrane thickness on microcapsule strength, permeability, and cell proliferation
Authors: Ma Ying , Zhang Ying , Wang Yu , Wang Qiuyan , Tan Mingqian , Liu Yang , Chen Li , Li Na , Yu Weiting , Ma Xiaojun 
Published: September 2012

AbstractCell microencapsulation is one of the promising strategies for in vitro production of proteins or in vivo delivery of therapeutic products. Membrane thickness controls microcapsule strength and permeability, which may in return affect cell growth and metabolism. In this study, the strength, permeability, and encapsulated Chinese hamster ovary cell proliferation and metabolism of four groups of microcapsules with different membrane thicknesses were investigated. It was found that increasing membrane thickness increases microcapsule strength, whereas decreases membrane permeability. During the first 6 days, cells within microcapsules with 10 μm thickness membrane proliferated fast and could reach a cell density of 1.9 × 107 cells/mL microcapsule with 92% cell density. A cell density of 5.5 × 107 cells/mL microcapsule with >85% cell density was achieved within microcapsules with 15 μm membrane thickness and these microcapsules kept over 88% integrity ratio after 11 days, which was much higher than that of microcapsules with 10 μm membrane thickness. Membrane with more than 20 μm thickness was not suited for encapsulated cell culture owing to low‐protein diffusion rate. These results indicated that cells survived shortly within the thinnest membrane thickness. There was a specific membrane thickness more suitable for cell growth for a long‐time culture. These findings will be useful for preparing microcapsules with the desired membrane thickness for microencapsulated cell culture dependent on various purposes. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
In vitro evaluation of hydroxyapatite–chitosan–gelatin composite membrane in guided tissue regeneration
Authors: Hunter Kimberly T. , Ma Teng 
Published: September 2012

AbstractResorbable biomaterials have been investigated as barrier membranes to compartmentalize the periodontal defects while selectively guiding osteoprogenitor cell proliferation and bone tissue expansion. Hydroxyapatite (H), chitosan (C), and gelatin (G) have chemical similarity to the structural components of natural bone and their composites have been tested as bone scaffolds. Human mesenchymal stem or stromal cells (hMSCs) are inducible osteoprogenitors and are responsible for bone tissue repair and regeneration. In this study, the dynamic interactions of hMSC with composite hydroxyapatite–chitosan–gelatin (HCG) membranes were investigated. The association of HCG formed a biodegradable membrane with ∼60 wt % water and an initial stiffness of ∼20 kPa. Preconditioning in serum‐containing media resulted in the formation nanopores in the HCG membranes and the increase of extracellular matrix (ECM) protein adsorption. Expression of integrin α2β1 and α5β1 coincided with ECM enrichment, suggesting the enhanced cell–ECM interactions. The elevated expression of bone marker proteins and genes in the HCG membranes suggests the progression of hMSC osteogenic differentiation in the absence of chemical induction. The results showed that the HCG membranes possess sufficient mechanical and structural properties to function as a barrier membrane, and that the adsorbed ECM proteins effectively functionalized the HCG membranes and promoted hMSC osteogenic differentiation. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
Study on the interaction between gelatin and polyurethanes derived from fatty acids
Authors: González‐Paz R. J. , Lligadas G. , Ronda J. C. , Galià M. , Ferreira A. M. , Boccafoschi F. , Ciardelli G. , Cádiz V. 
Published: September 2012

AbstractIn this study, gelatin was blended to proprietary noncytotoxic polyurethanes (PU) derived from vegetable oils with different weight ratios, as material for the preparation of novel biomedical products. The PU/gelatin blends were characterized for their morphology through scanning electron microscopy. Mechanical and thermal properties, chemical interactions between components, degradation behavior, surface properties, cell adhesion, and bioactivity were investigated as a function of the protein content. Higher blend miscibility was observed for the amorphous PUs, derived from oleic acid. Properties of PU/gelatin films were strongly influenced by the concentration of gelatin in the films. Gelatin enhanced the hydrophilicity, bioactivity, and cell adhesion of PUs. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
Surface chemistry of grafted expanded poly(tetrafluoroethylene) membranes modifies the in vitro proinflammatory response in macrophages
Authors: Chandler‐Temple Adrienne , Kingshott Peter , Wentrup‐Byrne Edeline , Cassady A. Ian , Grøndahl Lisbeth 
Published: September 2012

AbstractA series of surface‐modified expanded poly(tetrafluoroethylene) membranes showed varied levels of in vitro macrophage proinflammatory response. Membranes containing a mixture of phosphate and hydroxyl groups (as determined by X‐ray photoelectron spectroscopy analysis) stimulate greater macrophage activation than samples containing a mixture of phosphate and carboxylic acid segments. The types of proteins that adsorbed irreversibly from serum onto the two samples with the highest and lowest cellular response were investigated using surface‐matrix‐assisted laser desorption ionisation time‐of‐flight mass spectrometry. Distinct differences in the number and type of proteins that adsorbed were observed between these samples. A correlation was found between the main protein components adsorbed onto the surfaces and the resulting in vitro proinflammatory response. This study strongly supports the hypothesis that the cellular response is not controlled directly by surface properties but is mediated by specific protein adsorption events. This in turn highlights the importance of better understanding and controlling the properties of intelligent surface‐modified biomaterials. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.