bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of nanoclay and carbon nanofiber particles on rheology of molten polystyrene nanocomposites under supercritical carbon dioxide
Authors: Guo Zhihua , Yeh Shu‐Kai , Wingert Maxwell J. , Ellis Jeffrey L. , Tomasko David L. , Lee L. James 
Published: December 2009

AbstractThe effects of nanoparticles and high‐pressure carbon dioxide (CO2) on shear viscosity of polystyrene (PS) were studied. Master curves of PS, PS + 5 wt % carbon nanofibers (CNFs), and PS + 5 wt % nanoclay (Southern Clay 20A) without CO2 were created based on parallel‐plate measurements. The results showed that addition of nanoparticles increased the viscosity of the neat polymer. Steady‐state shear viscosity of PS in the presence of CO2 and nanoparticles was measured by a modified Couette rheometer. The effect of supercritical CO2 on these systems was characterized by shift factors. It was found that under the same temperature and CO2 pressure, CO2 reduced the viscosity less for both PS‐20A and PS‐CNFs than neat PS. Between the two types of nanoparticles, CNFs showed a larger viscosity reduction than 20A, indicating a higher CO2 affinity for CNFs than 20A. However, the advantage of CNFs over 20A for larger viscosity reduction decreased with higher temperature. A gravimetric method (magnetic suspension balance) was used to measure the excess adsorption of CO2 onto CNFs and nanoclay, thus, CO2 showed a higher affinity for CNFs. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Metabolic stability and determination of cytochrome P450 isoenzymes' contribution to the metabolism of medetomidine in dog liver microsomes
Authors: Duhamel Marie‐Claude , Troncy Éric , Beaudry Francis 
Published: December 2009

AbstractMedetomidine is a potent and selectiveα2‐adrenergic agonist. The activation ofα2‐adrenergic receptor mediates a variety of effects including sedation, analgesia, relief of anxiety, vasoconstriction and bradycardia. However, our main interest is the sedative effects of medetomidine when used as a premedicant prior surgery in companion animals, especially in dogs. Recently, data suggested that following intravenous infusion at six dosing regiments non‐linear pharmacokinetics was observed. Major causes of non‐linear pharmacokinetics are the elimination of the drug not following a simple first‐order kinetics and/or the elimination half‐life changing due to saturation of an enzyme system. The goal of this study was to establish the metabolic stability and determine the metabolic pathway of medetomidine in dog liver microsomes. Consequently, Michaelis–Menten parameters (Vmax,Km),T1/2andCLiwere determined. The incubations were performed in a microcentrifuge tube and containing various concentrations of medetomidine (10–5000 nm), 1 mg/mL of microsomal proteins suspended in 0.1 mphosphate buffer, pH 7.4. Microsomal suspensions were preincubated with NADPH (1 mm) for 5 min at 37°C prior to fortification with medetomidine. Samples were taken at various time points for kinetic information and the initial velocity (vi) was determined after 10 min incubation. The reaction was stopped by the addition of an internal standard solution (100 ng/mL of dextrometorphan in acetone). Medetomidine concentrations were determined using a selective and sensitive HPLC‐ESI/MS/MS method. Using non‐linear regression, we determined aKmvalue of 577 nm, indicating relatively low threshold enzyme saturation consistent with previousin vivoobservation. The metabolic stability was determined at a concentration of 100 nm(≪Km) and the observedT1/2was 90 min with aCLiof 0.008 mL/min indicating moderately low clearance in dog liver microsomes, also consistent with previousin vivodata. Moreover, results suggest that principally medetomidine is metabolized by the CYP3A with a small contribution from CYP2D and CYP2E. The participation of CYP3A is an important discovery since medetomidine is used as a premedicant in combination with fentanyl, ketamine and/or midazolam. These findings combined with a lowKmvalue may indicate that medetomidine can competitively inhibit the metabolism of these drugs and consequently significantly impair metabolic clearance. Copyright © 2009 John Wiley & Sons, Ltd.
Amino Acid Based Low‐Molecular‐Weight Ionogels as Efficient Dye‐Adsorbing Agents and Templates for the Synthesis of TiO2 Nanoparticles
Authors: Dutta Sounak , Das Dibyendu , Dasgupta Antara , Das Prasanta Kumar 
Published: December 2009

AbstractThe gelation of ionic liquids is attracting significant attention because of its large spectrum of applications across different disciplines. These ‘green solvents’ have been the solution to a number of common problems due to their eco‐friendly features. To expand their applications, the gelation of ionic liquids has been achieved by using amino acid‐based low‐molecular‐weight compounds. Variation of individual segments in the molecular skeleton of the gelators, which comprise the amino acid and the protecting groups at the N and C termini, led to an understanding of the structure–property correlation of the ionogelation process. An aromatic ring containing amino acid‐based molecules protected with a phenyl or cyclohexyl group at the N terminus were efficient in the gelation of ionic liquids. In the case of aliphatic amino acids, gelation was more prominent with a phenyl group as the N‐terminal protecting agent. The probable factors responsible for this supramolecular association of the gelators in ionic liquids have been studied with the help of field‐emission SEM, 1H NMR, FTIR, and luminescence studies. It is the hydrophilic–lipophilic balance that needs to be optimized for a molecule to induce gelation of the green solvents. Interestingly, to maximize the benefits from using these green solvents, these ionogels have been employed as templates for the synthesis of uniform‐sized TiO2 nanoparticles (25–30 nm). Furthermore, as a complement to their applications, ionogels serve as efficient adsorbents of both cationic and anionic dyes and were distinctly better relative to their organogel counterparts.
PDF receptor expression reveals direct interactions between circadian oscillators in drosophila
Authors: Im Seol Hee , Taghert Paul H. 
Published: December 2009

AbstractDaily rhythms of behavior are controlled by a circuit of circadian pacemaking neurons. In Drosophila, 150 pacemakers participate in this network, and recent observations suggest that the network is divisible into M and E oscillators, which normally interact and synchronize. Sixteen oscillator neurons (the small and large lateral neurons [LNvs]) express a neuropeptide called pigment‐dispersing factor (PDF) whose signaling is often equated with M oscillator output. Given the significance of PDF signaling to numerous aspects of behavioral and molecular rhythms, determining precisely where and how signaling via the PDF receptor (PDFR) occurs is now a central question in the field. Here we show that GAL4‐mediated rescue of pdfr phenotypes using a UAS‐PDFR transgene is insufficient to provide complete behavioral rescue. In contrast, we describe a ∼70‐kB PDF receptor (pdfr) transgene that does rescue the entire pdfr circadian behavioral phenotype. The transgene is widely but heterogeneously expressed among pacemakers, and also among a limited number of non‐pacemakers. Our results support an important hypothesis: the small LNv cells directly target a subset of the other crucial pacemaker neurons cells. Furthermore, expression of the transgene confirms an autocrine feedback signaling by PDF back to PDF‐expressing cells. Finally, the results present an unexpected PDF receptor site: the large LNv cells appear to target a population of non‐neuronal cells that resides at the base of the eye. J. Comp. Neurol. 518:1925–1945, 2010. © 2009 Wiley‐Liss, Inc.
Trans‐free fats through interesterification of canola oil/palm olein or fully hydrogenated soybean oil blends
Authors: Farmani Jamshid , Safari Mohammad , Hamedi Manouchehr 
Published: December 2009

AbstractBinary blends of canola oil (CO) and palm olein (POo) or fully hydrogenated soybean oil (FHSBO) were interesterified using commercial lipase, Lypozyme TL IM, or sodium methoxide. Free fatty acids (FFA) and soap content increased and peroxide value (PV) decreased after enzymatic or chemical interesterification. No difference was observed between the PV of enzymatically and chemically interesterified blends. Enzymatically interesterified fats contained higher FFA and lower soap content than chemically prepared fats. Slip melting point (SMP) and solid‐fat content (SFC) of CO and POo blends increased, whereas those of CO and FHSBO blends decreased after chemical or enzymatic interesterification. Enzymatically interesterified CO and POo blends had lower SMP and SFC (at some temperatures) than chemically interesterified blends. The status was reverse when comparing chemically and enzymatically interesterified CO and FHSBO blends. The induction period for oxidation at 120°C of blends decreased after interesterification. However, chemically interesterified blends were more oxidatively stable than enzymatically interesterified blends. Interesterified blends of CO and POo or FHSBO displayed characteristics suited to application as trans‐free soft tub, stick, roll‐in and baker's margarine, cake shortening and vanaspati fat.
Variability of the essential oil composition in the sage collection of the Genebank Gatersleben: a new viridiflorol chemotype
Authors: Lamien‐Meda Aline , Schmiderer Corinna , Lohwasser Ulrike , Börner Andreas , Franz Chlodwig , Novak Johannes 
Published: December 2009

AbstractThe variation in quantity and quality of the essential oils of garden sage (Salvia officinalis L.) collection, cultivated at the Leibniz Institute of Plant Genetics and Crop Plant Research in Gatersleben, Germany, was studied. The aerial parts of 10 individual plants per accession (19 accessions) were collected at the beginning of the flowering period in two consecutive years from the same experimental field, and essential oil (EO) content and composition were analysed. The EO quantity was in the ranges 0.3–2.2% w/w in the first year and 0.9–2.5% w/w in the second year. The highest EO content was observed in a Croatian accession. The mean EO quantities in the second year were 1–1.6‐fold higher than in the first year, and the correlation between the two years' EO content was 0.77. The essential oil composition was not variable from 2007 to 2008 and was comparable to results already published, with the exception of two accessions from Romania with viridiflorol as dominant compound and low amounts of α‐ and β‐thujone, representing a new Salvia officinalis chemotype which would be ideal and safer for drinks and meals. Copyright © 2009 John Wiley & Sons, Ltd.
Three Terpenoids and a Tocopherol‐Related Compound from Ricinus communis
Authors: Tan Qin‐Gang , Cai Xiang‐Hai , Du Zhi‐Zhi , Luo Xiao‐Dong 
Published: December 2009

AbstractFour new compounds named (3E,7Z,11E)‐19‐hydroxycasba‐3,7,11‐trien‐5‐one (1), 6α‐hydroxy‐10β‐methoxy‐7α,8α‐epoxy‐5‐oxocasbane‐20,10‐olide (2), 15α‐hydroxylup‐20(29)‐en‐3‐one (3), and (2R,4aR, 8aR)‐3,4,4a,8a‐tetrahydro‐4a‐hydroxy‐2,6,7,8a‐tetramethyl‐2‐(4,8,12‐trimethyltridecyl)‐2H‐chromene‐5,8‐dione (4) were isolated from the MeOH extracts of the aerial parts of Ricinus communis L. by chromatographic methods. Their structures were elucidated by extensive spectroscopic experiments.
Analytical model for fully three‐dimensional radial dispersion in a finite‐thickness aquifer
Authors: Chen Jui‐Sheng 
Published: December 2009

AbstractAnalytical solutions for contaminant transport in a non‐uniform flow filed are very difficult and relatively rare in subsurface hydrology. The difficulty is because of the fact that velocity vector in the non‐uniform flow field is space‐dependent rather than constant. In this study, an analytical model is presented for describing the three‐dimensional contaminant transport from an area source in a radial flow field which is a simplest case of the non‐uniform flow. The development of the analytical model is achieved by coupling the power series technique, the Laplace transform and the two finite Fourier cosine transform. The developed analytical model is examined by comparing with the Laplace transform finite difference (LTFD) solution. Excellent agreements between the developed analytical model and the numerical model certificate the accuracy of the developed model. The developed model can evaluate solution for Peclet number up to 100. Moreover, the mathematical behaviours of the developed solution are also studied. More specifically, a hypothetical convergent flow tracer test is considered as an illustrative example to demonstrate the three‐dimensional concentration distribution in a radial flow field. The developed model can serve as benchmark to check the more comprehensive three‐dimensional numerical solutions describing non‐uniform flow contaminant transport. Copyright © 2009 John Wiley & Sons, Ltd.
miR‐212 is downregulated and suppresses methyl‐CpG‐binding protein MeCP2 in human gastric cancer
Authors: Wada Rie , Akiyama Yoshimitsu , Hashimoto Yutaka , Fukamachi Hiroshi , Yuasa Yasuhito 
Published: December 2009

AbstractTo clarify the role of micro (mi) RNAs in gastric carcinogenesis, we studied the expression and function of miRNAs in gastric carcinoma (GC) cells. Initially, we performed microarray analysis using total RNA from 3 human GC cell lines and noncancerous gastric tissue. Among the downregulated miRNAs in GC cells, miR‐212 expression was decreased in all 8 GC cell lines examined and a significant decrease of miR‐212 expression in human primary GC tissues was also observed in 6 of 11 cases. Transfection of the precursor miR‐212 molecule induced decreased growth of 3 GC cell lines. Using 3 different databases, methyl‐CpG‐binding protein MeCP2 was postulated to be a target of miR‐212. As seen on reporter assaying, miR‐212 repressed the construct with the MECP2 3′‐UTR. Ectopic expression of miR‐212 repressed expression of the MeCP2 protein but not the MECP2 mRNA level. These data suggest that downregulation of miR‐212 may be related to gastric carcinogenesis through its target genes, such as MECP2.
TGF‐β inactivation and TGF‐α overexpression cooperate in an in vivo mouse model to induce hepatocellular carcinoma that recapitulates molecular features of human liver cancer
Authors: Baek Ji Yeon , Morris Shelli M. , Campbell Jean , Fausto Nelson , Yeh Matthew M. , Grady William M. 
Published: December 2009

AbstractHepatocellular carcinoma (HCC) results from the cumulative effects of deregulated tumor suppressor genes and oncogenes. The tumor suppressor and oncogenes commonly affected include growth factors, receptors and their downstream signaling pathway components. The overexpression of transforming growth factor alpha (TGF‐α) and the inhibition of TGF‐β signaling are especially common in human liver cancer. Thus, we assessed whether TGF‐α overexpression and TGF‐β signaling inactivation cooperate in hepatocarcinogenesis using an in vivo mouse model, MT1/TGFa;AlbCre/Tgfbr2flx/flx mice (“TGFa;Tgfbr2hepko”), which overexpresses TGF‐α and lacks a TGF‐β receptor in the liver. TGF‐β signaling inactivation did not alter the frequency or number of cancers in mice with overexpression of TGF‐α. However, the tumors in the TGFa;Tgfbr2hepko mice displayed increased proliferation and increased cdk2, cyclin E and cyclin A expression as well as decreased Cdkn1a/p21 expression compared to normal liver and compared to the cancers arising in the TGF‐α overexpressing mice with intact TGF‐β receptors. Increased phosphorylated ERK1/2 expression was also present in the tumors from the TGFa;Tgfbr2hepko mice and correlated with downregulated Raf kinase inhibitor protein expression, which is a common molecular event in human HCC. Thus, TGF‐β signaling inactivation appears to cooperate with TGF‐α in vivo to promote the formation of liver cancer that recapitulates molecular features of human HCC.
Cracking down on youth tobacco may influence drug use
Authors: Jason Leonard A. , Pokorny Steven B. , Adams Monica , Nihls Annie , Kim Hyo Yeon , Hunt Yvonne 
Published: December 2009

AbstractThis study evaluated the influence of tobacco possession–use–purchase (PUP) law enforcement and illicit drug use and offers. Twenty‐four towns were randomly assigned into two conditions. Both conditions focused on reducing minors' access to commercial sources of tobacco. The communities assigned to the experimental condition also increased their PUP law enforcement, whereas among communities in the control condition, PUP law enforcement remained at low levels. A hierarchical linear modeling analytical approach was selected due to the multilevel data and nested design. The likelihood of a child currently using drugs, ever having used drugs, or illicit drug offers was lower in the experimental versus control conditions. These outcomes suggest that police efforts to reduce specific substance use behaviors (i.e., underage tobacco use) may have a positive spillover effect and help reduce teen drug use and illicit drug offers. © 2009 Wiley Periodicals, Inc.
20,23‐dihydroxyvitamin D3, novel P450scc product, stimulates differentiation and inhibits proliferation and NF‐κB activity in human keratinocytes
Authors: Janjetovic Zorica , Tuckey Robert C. , Nguyen Minh N. , Thorpe Edwin M. , Slominski Andrzej T. 
Published: December 2009

AbstractWe have examined effects of the 20,23‐dihydroxyvitamin D3 (20,23(OH)2D3), on differentiation and proliferation of human keratinocytes and the anti‐inflammatory potential of 20,23(OH)2D3 from its action on nuclear factor‐κB (NF‐κB). 20,23(OH)2D3 inhibited growth of keratinocytes with a potency comparable to that for 1,25‐dihydroxyvitamin D3 (1,25(OH)2D3). Cell cycle analysis showed that this inhibition was associated with G1/G0 and G2/M arrests. 20,23(OH)2D3 stimulated production of involucrin mRNA and inhibited production of cytokeratin 14 mRNA in a manner similar to that seen for 1,25(OH)2D3. Flow cytometry showed that these effects were accompanied by increased involucrin protein expression, and an increase in the cell size and granularity. Silencing of the vitamin D receptor (VDR) by corresponding siRNA abolished the stimulatory effect on involucrin gene expression demonstrating an involvement of VDR in 20,23(OH)2D3 action. This mode of action was further substantiated by stimulation of CYP24 gene expression and stimulation of the CYP24 promoter‐driven reporter gene activity. 20,23(OH)2D3 displayed several fold lower potency for induction of CYP24 gene expression than 1,25(OH)2D3. Finally, 20,23(OH)2D3 inhibited the transcriptional activity of NF‐κB in keratinocytes as demonstrated by EMSA, NF‐κB‐driven reporter gene activity assays and measurements of translocation of p65 from the cytoplasm to the nucleus. These inhibitory effects were connected with stimulation of the expression of IκBα with subsequent sequestration of NF‐κB in the cytoplasm and consequent attenuation of transcriptional activity. In summary, we have characterized 20,23(OH)2D3 as a novel secosteroidal regulator of keratinocytes proliferation and differentiation and a modifier of their immune activity. J. Cell. Physiol. 223: 36–48, 2010. © 2009 Wiley‐Liss, Inc.
Genomic organization of microRNAs
Authors: Olena Abigail F. , Patton James G. 
Published: December 2009

AbstractmicroRNAs (miRNAs) are small (∼22 nt) noncoding RNAs that have been shown to regulate gene expression post‐transcriptionally. They function by pairing with the 3′ UTR of target mRNAs and repressing translation or by targeting the mRNA for degradation. miRNAs are involved in diverse aspects of development, maintenance, and disease, and are largely evolutionarily conserved in metazoans. Searching the genomes of organisms from viruses to worms to humans has revealed potentially thousands of miRNA genes. Understanding the patterns of genomic organization between species cannot only help to refine tools to identify new miRNAs, but also provide insight into miRNA biogenesis and function. J. Cell. Physiol. 222: 540–545, 2010. © 2009 Wiley‐Liss, Inc.
Upregulation of MMP‐9 production by TNFα in keratinocytes and its attenuation by vitamin D
Authors: Bahar‐Shany K. , Ravid A. , Koren R. 
Published: December 2009

AbstractMMP‐9, a member of the matrix metalloproteinase family that degrades collagen IV and processes chemokines and cytokines, participates in epidermal remodeling in response to stress and injury. Limited activity of MMP‐9 is essential while excessive activity is deleterious to the healing process. Tumor necrosis factor (TNFα), a key mediator of cutaneous inflammation, is a powerful inducer of MMP‐9. Calcitriol, the hormonally active vitamin D metabolite, and its analogs are known to attenuate epidermal inflammation. We aimed to examine the modulation of MMP‐9 by calcitriol in TNFα‐treated keratinocytes. The immortalized HaCaT keratinocytes were treated with TNFα in the absence of exogenous growth factors or active ingredients. MMP‐9 production was quantified by gelatin zymography and real‐time RT‐PCR. Activation of signaling cascades was assessed by western blot analysis and DNA‐binding activity of transcription factors was determined by EMSA. Exposure to TNFα markedly increased the protein and mRNA levels of MMP‐9, while pretreatment with calcitriol dose dependently reduced this effect. Employing specific inhibitors we established that the induction of MMP‐9 by TNFα was dependent on the activity of the epidermal growth factor receptor, c‐Jun‐N‐terminal kinase (JNK), NFκB and extracellular signal‐regulated kinase‐1/2. The effect of calcitriol was associated with inhibition of JNK activation and reduction of DNA‐binding activities of the transcription factors activator protein‐1 (AP‐1) and NFκB following treatment with TNFα. By down‐regulating MMP‐9 levels active vitamin D derivatives may attenuate deleterious effects due to excessive TNFα‐induced proteolytic activity associated with cutaneous inflammation. J. Cell. Physiol. 222: 729–737, 2010. © 2009 Wiley‐Liss, Inc.
Kinetic properties of ASC protein aggregation in epithelial cells
Authors: Cheng Jun , Waite Andrea L. , Tkaczyk Eric R. , Ke Kevin , Richards Neil , Hunt Alan J. , Gumucio Deborah L. 
Published: December 2009

AbstractApoptosis‐associated speck‐like protein with CARD domain (ASC), an adaptor protein composed of caspase recruitment and pyrin domains, can efficiently self‐associate to form a large spherical structure, called a speck. Although ASC aggregation is generally involved with both inflammatory processes and apoptosis, the detailed dynamics of speck formation have not been characterized. In this report, speck formation in HeLa cells transfected with ASC is examined by time‐lapse live‐imaging by confocal laser scanning microscopy. The results show that ASC aggregation is a very rapid and tightly regulated process. Prior to speck formation, soluble ASC aggregation is a low probability event, and the affinity of ASC subunits for one another is very low. Following a speck nucleation event, the affinity for further addition of ASC subunits increases dramatically, and aggregation is a highly energetically favorable reaction (Gibbs free energy ∼ −40 kJ/mol). This leads to a rapid depletion of soluble ASC, making it highly unlikely that a second speck will form inside the same cell and assuring that speck formation is “all or none,” with a well‐defined end point. Comparison with kinetic models of the aggregation process indicates diffusion, instead of active transport, is the dominant process for speck growth. Though speck formation and aggresome formation share some properties, we show that the two processes are distinct. J. Cell. Physiol. 222: 738–747, 2010. © 2009 Wiley‐Liss, Inc.