bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enantiodiscrimination of methamphetamine by circular dichroism using a porphyrin tweezer
Authors: Anderson Marcus , Wilcox Katie , Guericke Mike , Chu Han , Wilson Mark V. , Wilson Erin , Lucas Kerry , Holmes Andrea E. 
Published: July 2009

AbstractUsing exciton‐coupled circular dichroism (ECCD) spectroscopy, our lab was able to differentiate between the two enantiomers of methamphetamine using a commercially available porphyrin tweezer as an achiral host. The host–guest complex formed with (+)‐(S)‐methamphetamine produced a negative bisignate‐shaped ECCD spectrum, whereas the complex formed with (−)‐(R)‐methamphetamine produced a positive one. This sensitive technique could serve as an alternative method for the enantiodiscrimination of chiral methamphetamine, a commonly abused drug in the United States. Chirality 2010. © 2009 Wiley‐Liss, Inc.
Stereoselective transport and uptake of propranolol across human intestinal Caco‐2 cell monolayers
Authors: Wang Yi , Cao Jiang , Wang Xiaodan , Zeng Su 
Published: July 2009

AbstractThe transport and uptake of individual propranolol (PPL) enantiomers were studied in human intestinal Caco‐2 cell monolayers, and a reversed‐phase HPLC‐UV assay was used for quantitative analysis. S‐PPL and R‐PPL across Caco‐2 cell monolayers was determined in the concentrations range of 10–500 μM in both apical (AP) to basolateral (BL) and BL to AP directions. S‐PPL exhibited greater permeability than R‐PPL in the AP to BL direction, whereas in the BL to AP direction S‐enantiomer transported less than R‐enantiomer. Uptake of R‐PPL was significantly higher than that of S‐PPL either from AP side or from BL side. The statistically significant differences in uptake were observed at the concentrations range from 10 to 50 μM. Furthermore, the apparent Michaelis constant (Km) and maximal velocity (Vmax) also showed significant difference between the two enantiomers. Moreover, the AP to BL transport of PPL enantiomer was markedly decreased by lowering the pH of the apical side but it did not affect the stereoselectivity of PPL across Caco‐2 cell monolayers. The transport and uptake of PPL in the BL to AP direction was not influenced by several protein inhibitors. The results suggest that PPL enantiomers showed stereoselective transport and uptake across the Caco‐2 cell monolayers. A special transport mechanism capable of directing the PPL enantiomers might be present in the Caco‐2 monolayers. Chirality 2010. © 2009 Wiley‐Liss, Inc.
Rieselbettreaktoren unter Filtrationsbedingungen – Mechanismus der Ablagerung, Hydrodynamische Folgen, Methoden zur Begrenzung der Filterwirkung
Authors: Hamidipour M. , Schubert M. , Larachi F. 
Published: July 2009

AbstractSchüttungen in Rieselbettreaktoren wirken gegenüber Feinpartikeln als Filter. Sowohl in Festbettbioreaktoren als auch bei petrochemischen Anwendungen wird durch die reduzierte Permeabilität und die damit verbundenen Druckverluste die Wirtschaftlichkeit der Prozesse stark beeinträchtigt. Obwohl den Anwendern das Problem bewusst ist, sind die Kenntnisse zur Filterwirkung von Rieselbettreaktoren bisher nicht intensiv erforscht. Die Mechanismen der Ablagerung und die Auswirkungen auf die Hydrodynamik wurden am Beispiel von Kaolin‐Feinpartikeln, die ein dominierender Bestandteil in den nachgelagerten Behandlungsstufen bei der Verarbeitung von Athabasca‐Ölsanden sind, untersucht. Zusätzlich werden effektive technische Lösungen und operative Methoden zur Begrenzung der Ablagerungen vorgestellt.
Konzeptstudie: Strukturierter Rieselbettreaktor
Authors: Bauer T. , Haase S. , Lange R. 
Published: July 2009

AbstractDas Konzept eines strukturierten Rieselbettreaktors kombiniert eine wabenförmige Grundstruktur mit geraden Strömungskanälen und darin eingebrachten kugelförmigen Katalysatorpartikeln. Damit verbindet die neuartige katalytisch aktive Reaktorpackung Vorteile konventioneller Rieselbetten mit denen strukturierter Packungen. Der vorliegende Beitrag diskutiert charakteristische Kenngrößen strukturierter Rieselbetten und befasst sich mit einer ersten experimentellen Leistungsevaluation des Konzeptes am Beispiel der Hydrierung von alpha‐Methylstyrol.
Computational Investigation of 1,3‐H and 1,5‐H Shifts in Isomerization of Enol Acetate of 2‐Aceto‐1,3‐cyclohexanedione
Authors: WANG Yanhua , CHEN Xuesong , LI Li , ZOU Jianwei 
Published: June 2009

AbstractThe mechanism of the isomerization of the enol acetate of 2‐aceto‐1,3‐cyclohexanedione has been discussed in detail. The possible 1,3‐H and 1,5‐H shifts in isomerization were investigated systematically. It seems that this mechanism includes two successive 1,5‐sigmatropic shifts, i.e. 1,5‐acetyl and 1,5‐H shifts. Density functional theory calculations have been performed to evaluate the reasonability of the proposed mechanisms. The effect of the solvent upon the rate‐determining steps has been also considered. In addition, the relative stabilities of the reactant, the product as well as the intermediates in the proposed mechanism have been examined and discussed.
Efficient Synthetic Route to Carbopyronine Fluorenscent Dye Intermediate
Authors: GU Lijun , YANG Bingqin , LIU Feilong , BAI Yinjuan 
Published: June 2009

AbstractAn efficient synthesis of 2,7‐bis(dimethylamino)‐9,10‐dihydro‐9,9‐dimethylanthracene via a non‐protic Lewis acid assisted cyclization reaction in a high yield was described. The key step was a Lewis acid assisted cyclization reaction. Several non‐protic Lewis acids were investigated and the optimal condition of cyclization reaction was determined to be 2.5 equiv. of Lewis acid at 0°C for 6 h and at room temperature for 10 h.
Downregulation of Peroxisome Proliferator‐activated Receptor‐γ Expression in Hypertensive Atrial Fibrillation
Authors: Chen Xiaoping , Bing Ziyi , He Jiyun , Jiang Lingyun , Luo Xiaojia , Su Yanling , Kan Bing , Huang Dejia , Wei Yuquan 
Published: June 2009

AbstractBackgroundNumerous evidence has suggested that either hypertension or atrial fibrillation (AF) is associated with systemic inflammation. Peroxisome proliferator‐activated receptor‐γ (PPARγ) has been proved to have anti‐inflammatory effects and is implicated as a molecular pathway involved in many cardiovascular diseases, such as hypertension. The correlation between PPARγ inflammation and AF is still unknown.MethodsUsing a case‐control study design, 57 patients with hypertensive AF (persistent AF: 32, paroxysmal AF: 25) were included into the study groups. A total of 32 age‐matched patients with hypertension, but without AF were selected as the control group. The expressions of PPARγ, interleukin‐6 (IL‐6), and tumor necrosis factor‐α (TNF‐α) mRNA in monocytes were detected by using a reverse transcription‐polymerase chain reaction (RT‐PCR). Interleukin‐1 (IL‐1) was measured by immunoenzymetric methods.ResultsThe PPARγ mRNA was markedly decreased in the hypertensive AF group as compared with the hypertensive non‐AF group, and it was significantly lower in persistent AF than paroxysmal AF (0.222 ± 0.0702 vs 0.564 ± 0.0436, P<0.01). TNF‐α mRNA, IL‐6 mRNA, and IL‐1 were increased in patients with hypertensive AF compared to the non‐AF group and it was even higher in persistent AF than in paroxysmal AF (0.721 ± 0.0541 vs 0.530 ± 0.0496, 0.567 ± 0.044 vs 0.457 ± 0.0505, 325.61 ± 88.10 vs 190.65 ± 59.38, respectively, P<0.01). TNF‐α, IL‐6, and IL‐1 were in negative correlation with PPARγ, the correlation coefficient was − 0.854, − 0.769, and − 0.702, respectively (P<0.01).ConclusionsIn hypertensive patients, increased inflammatory cytokines were associated with increased incidence of AF and atrial remodeling; PPARγ may be involved in the pathogenesis of AF by regulation of inflammation. Copyright © 2009 Wiley Periodicals, Inc.
Effects of Renovation Work on Air Quality and Occupants Health in University Buildings
Authors: Hasegawa Asako , Schleibinger Hans , Nong Gang , Lusztyk Ewa 
Published: June 2009

AbstractThis study aimed to prevent chemical air pollution and reduce its influence on occupants' health in a university building under renovation. Since starting the renovation work, the occupants' health status was monitored using questionnaires every summer and winter. According to a first questionnaire collected before the renovation, subjective symptoms were not observed. However, some occupants complained about odor after moving into their new rooms. Therefore, all interior materials used for the construction work were examined in small chambers to obtain their chemical emission characteristics. The assembled floor, which was a polyvinyl chloride floor sheet combined with a concrete slab by adhesive, was predicted to be the main source of odor in the renovated rooms. Two strategies were implemented individually in rooms to remove these odorous chemicals; a chemical filter in indoor air conditioning units and forced ventilation with hot‐humid outdoor air. The performance of each technique was validated by measuring the indoor concentration before and after operation. These results showed that both strategies had a significant effect on reducing volatile organic compounds (VOCs), in a practical way.
Two‐group classification using the Bayesian data reduction algorithm
Authors: Kline Douglas M. 
Published: July 2009

AbstractThe Bayesian data reduction algorithm (BDRA) is compared to traditional classification methods as well as feed forward artificial neural networks through a rigorous experiment. The BDRA performs comparably to alternative techniques and approaches theoretical optimal classification rates. Furthermore, it has a fundamentally different method for determining class membership. This study is novel in that it explores how the BDRA relates to established techniques, how it might be used in an explanatory manner, and how best to use it. © 2009 Wiley Periodicals, Inc. Complexity, 2010
Harmonization of light scatter and fluorescence flow cytometry profiles obtained after staining peripheral blood leucocytes for cell surface‐only versus intracellular antigens with the Fix & Perm™ reagent
Authors: da Costa Elaine Sobral , Peres Rodrigo Tosta , Almeida Julia , Lécrevisse Quentin , Arroyo María Elena , Teodósio Cristina , Pedreira Carlos Eduardo , van Dongen Jacques J. M. , Orfao Alberto 
Published: July 2009

AbstractStaining for intracellular markers with the Fix & Perm™ reagent is associated with variations in the scatter properties of leucocytes, limiting automated analysis of flow cytometry (FCM) data. Here, we investigated those variables significantly contributing to changes in the light scatter, autofluorescence, and bcl2 staining characteristics of peripheral blood (PB) leucocytes, after fixation with Fix & PermTM. Our major aim was to evaluate a new mathematical approach for automated harmonization of FCM data from datafiles corresponding to aliquots of a sample treated with cell‐surface‐only versus Fix & Perm intracellular staining techniques. Overall, neither the anticoagulant used nor sample storage for <24 h showed significant impact on the light scatter and fluorescence properties of PB leucocytes; similarly, the duration of the fixation period (once >15 min were used) had a minimum impact on the FCM properties of PB leucocytes. Conversely, changes in cell/protein concentrations and the fixative/sample (vol/vol) ratio had a clear impact on the light scatter features of some populations of leucocytes. Accordingly, lower cell/protein concentrations were associated with lower scatter values, particularly for the neutrophils. Such changes could be partially corrected through the use of higher fixative to sample volume ratios. Despite the variable changes detected between aliquots of the same sample treated with cell surface‐only versus intracellular staining procedures, the new mathematical approach here proposed and evaluated for automated harmonization of common parameters in both datafiles, could correct the FCM profiles of leucocytes derived from cells undergoing conventional fixation/permeabilization procedures, and made them indistinguishable from those corresponding to aliquots of the same sample treated with cell‐surface‐only staining techniques. © 2009 Clinical Cytometry Society
Rare‐Earth Tetrel Antimonides RE5TtxSb3–x (RE = La–Nd; Tt = Si, Ge)
Authors: Bie Haiying , Mar Arthur 
Published: July 2009

AbstractTernary rare‐earth tetrel antimonides RE5TtxSb3–x (RE = La–Nd; Tt = Si, Ge) have been prepared by arc‐melting of the elements and annealing at 800 °C. Their crystal structures were determined by single‐crystal and powder X‐ray diffraction methods. These ternary antimonides adopt a structure (β‐Yb5Sb3‐type, orthorhombic, space group Pnma, Z = 4) that is different from those of the parent binary phases RE5Sb3 (Mn5Si3‐type), RE5Si3 (Cr5B3‐type), or RE5Ge3 (Mn5Si3‐type) for RE = La–Nd. The range of solid solubility determined for a representative series, La5GexSb3–x, is relatively wide, 0.9 ≤ x ≤ 1.6. The disorder arises largely from the partial substitution of Tt atoms into Sb sites centred within RE6 trigonal prisms. Columns of confacial RE6 trigonal prisms are connected to each other through edge‐sharing to form a three‐dimensional framework outlining hexagonal channels filled by ribbons of [RE2Tt2] rhombs. Band‐structure calculations provided support for these site preferences and the range of solid solubility in La5GexSb3–x, which can be related largely to changes in the heteroatomic La–Ge and La–Sb bonding interactions. Magnetic measurements on RE5TtxSb3–x (RE = La, Pr, Nd) revealed Pauli paramagnetic behaviour for the La members and multiple low‐temperature transitions (likely involving ferromagnetic ordering) for the Pr and Nd members. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Towards Molecular Wires Based on Metal‐Organic Frameworks (Eur. J. Inorg. Chem. 20/2009)
Authors: Mas‐Ballesté Rubén , Castillo Oscar , Sanz Miguel Pablo J. , Olea David , Gómez‐Herrero Julio , Zamora Félix 
Published: June 2009

AbstractThe cover picture shows an Atomic Force Microscopy image of single chains based on a one‐dimensional oxalato‐bridged manganese(II) complex with 4‐aminotriazole isolated on a graphite surface. The inset shows the height profile of two of these chains. This is an example of the results obtained in the adsorption of coordination polymers on surfaces. The Microreview by F. Zamora et al. on p. 2885 ff focuses on the state‐of‐the‐art experimental procedures for the isolation of single chains of these supramolecules and on different pathways to obtain molecular assemblies. Potential applications of these compounds as molecular wires are also presented.
Performance of very‐high‐order upwind schemes for DNS of compressible wall‐turbulence
Authors: Gerolymos G. A. , Sénéchal D. , Vallet I. 
Published: July 2009

AbstractThe purpose of the present paper is to evaluate very‐high‐order upwind schemes for the direct numerical simulation (DNS) of compressible wall‐turbulence. We study upwind‐biased (UW) and weighted essentially nonoscillatory (WENO) schemes of increasingly higher order‐of‐accuracy (J. Comp. Phys. 2000; 160:405–452), extended up to WENO17 (AIAA Paper 2009‐1612, 2009). Analysis of the advection–diffusion equation, both as Δx→0 (consistency), and for fixed finite cell‐Reynolds‐number ReΔx (grid‐resolution), indicates that the very‐high‐order upwind schemes have satisfactory resolution in terms of points‐per‐wavelength (PPW). Computational results for compressible channel flow (Re∈[180, 230]; M̄CL∈[0.35, 1.5]) are examined to assess the influence of the spatial order of accuracy and the computational grid‐resolution on predicted turbulence statistics, by comparison with existing compressible and incompressible DNS databases. Despite the use of baseline O(Δt2) time‐integration and O(Δx2) discretization of the viscous terms, comparative studies of various orders‐of‐accuracy for the convective terms demonstrate that very‐high‐order upwind schemes can reproduce all the DNS details obtained by pseudospectral schemes, on computational grids of only slightly higher density. Copyright © 2009 John Wiley & Sons, Ltd.
Numerical solution of the two‐phase expansion of a metastable flashing liquid jet using the dispersion‐controlled dissipative scheme
Authors: Avila J. A. J. , Pimenta M. M. , Simões‐Moreira J. R. 
Published: July 2009

AbstractThis paper presents a study of the stationary phenomenon of superheated or metastable liquid jets, flashing into a two‐dimensional axisymmetric domain, while in the two‐phase region. In general, the phenomenon starts off when a high‐pressure, high‐temperature liquid jet emerges from a small nozzle or orifice expanding into a low‐pressure chamber, below its saturation pressure taken at the injection temperature. As the process evolves, crossing the saturation curve, one observes that the fluid remains in the liquid phase reaching a superheated condition. Then, the liquid undergoes an abrupt phase change by means of an oblique evaporation wave. Across this phase change the superheated liquid becomes a two‐phase high‐speed mixture in various directions, expanding to supersonic velocities. In order to reach the downstream pressure, the supersonic fluid continues to expand, crossing a complex bow shock wave. The balance equations that govern the phenomenon are mass conservation, momentum conservation, and energy conservation, plus an equation‐of‐state for the substance. A false‐transient model is implemented using the shock capturing scheme: dispersion‐controlled dissipative (DCD), which was used to calculate the flow conditions as the steady‐state condition is reached. Numerical results with computational code DCD‐2D v1 have been analyzed. Copyright © 2009 John Wiley & Sons, Ltd.
Sibunit Carbon‐Based Cathodes for Proton‐Exchange‐Membrane Fuel Cells
Authors: Lebedeva N. P. , Booij A. S. , Voropaev I. N. , Simonov P. A. , Romanenko A. V. 
Published: July 2009

AbstractPreparation, characterisation and evaluation of a novel cathode catalyst for H2/O2 PEMFC – 40 wt.‐% Pt/Sibunit 1562P carbon – is presented. The performance of the cathodes based on the latter material is compared to that of a widely used commercially available reference material – 40 wt.‐% Pt/Vulcan XC 72R – Hispec 4000 (Johnson Matthey, UK). It has been found that the mass activity of the 40 wt.‐% Pt/Sibunit 1562P catalyst exceeds that of a commercial benchmark by a factor of 2 due to a better dispersion of the Pt metal realised in the Sibunit – supported catalyst. Mass transport properties of the two catalysts studied are virtually equal.
Pharmacological inhibition of integrin αvβ3 aggravates experimental liver fibrosis and suppresses hepatic angiogenesis #
Authors: Patsenker Eleonora , Popov Yury , Stickel Felix , Schneider Vreni , Ledermann Monika , Sägesser Hans , Niedobitek Gerald , Goodman Simon L. , Schuppan Detlef 
Published: July 2009

Abstract
The vitronectin receptor integrin αvβ3 promotes angiogenesis by mediating migration and proliferation of endothelial cells, but also drives fibrogenic activation of hepatic stellate cells (HSCs) in vitro. Expecting antifibrotic synergism, we studied the effect of αvβ3 inhibition in two in vivo models of liver fibrogenesis. Liver fibrosis was induced in rats by way of bile duct ligation (BDL) for 6 weeks or thioacetamide (TAA) injections for 12 weeks. A specific αvβ3 (αvβ5) inhibitor (Cilengitide) was given intraperitoneally twice daily at 15 mg/kg during BDL or after TAA administration. Liver collagen was determined as hydroxyproline, and gene expression was quantified by way of quantitative polymerase chain reaction. Liver angiogenesis, macrophage infiltration, and hypoxia were assessed by way of CD31, CD68 and hypoxia-inducible factor-1α immunostaining. Cilengitide decreased overall vessel formation. This was significant in portal areas of BDL and septal areas of TAA fibrotic rats and was associated with a significant increase of liver collagen by 31% (BDL) and 27% (TAA), and up-regulation of profibrogenic genes and matrix metalloproteinase-13. Treatment increased gamma glutamyl transpeptidase in both models, while other serum markers remained unchanged. αvβ3 inhibition resulted in mild liver hypoxia, as evidenced by up-regulation of hypoxia-inducible genes. Liver infiltration by macrophages/Kupffer cells was not affected, although increases in tumor necrosis factor α, interleukin-18, and cyclooxygenase-2 messenger RNA indicated modest macrophage activation. Conclusion: Specific inhibition of integrin αvβ3 (αvβ5) in vivo decreased angiogenesis but worsened biliary (BDL) and septal (TAA) fibrosis, despite its antifibrogenic effect on HSCs in vitro. Angiogenesis inhibitors should be used with caution in patients with hepatic fibrosis. (Hepatology 2009.)
HuR regulates gap junctional intercellular communication by controlling β-catenin levels and adherens junction integrity #
Authors: Ale-Agha Niloofar , Galban Stefanie , Sobieroy Christiane , Abdelmohsen Kotb , Gorospe Myriam , Sies Helmut , Klotz Lars-Oliver 
Published: July 2009

Abstract
Gap junctional intercellular communication (GJIC) plays a critical role in the regulation of tissue homeostasis and carcinogenesis and is modulated by the levels, subcellular localization, and posttranslational modification of gap junction proteins, the connexins (Cx). Here, using oval cell-like rat liver epithelial cells, we demonstrate that the RNA-binding protein HuR promotes GJIC through two mechanisms. First, HuR silencing lowered the levels of Cx43 protein and Cx43 messenger RNA (mRNA), and decreased Cx43 mRNA half-life. This regulation was likely due to the direct stabilization of Cx43 mRNA by HuR, because HuR associated directly with Cx43 mRNA, a transcript that bears signature adenylate-uridylate-rich (AU-rich) and uridylate-rich (U-rich) sequences in its 3′-untranslated region. Second, HuR silencing reduced both half-life and the levels of β-catenin mRNA, also a target of HuR; accordingly, HuR silencing lowered the levels of whole-cell and membrane-associated β-catenin. Coimmunoprecipitation experiments showed a direct interaction between β-catenin and Cx43. Small interfering RNA (siRNA)-mediated depletion of β-catenin recapitulated the effects of decreasing HuR levels: it attenuated GJIC, decreased Cx43 levels, and redistributed Cx43 to the cytoplasm, suggesting that depletion of β-catenin in HuR-silenced cells contributed to lowering Cx43 levels at the membrane. Finally, HuR was demonstrated to support GJIC after exposure to a genotoxic agent, doxorubicin, or an inducer of differentiation processes, retinoic acid, thus pointing to a crucial role of HuR in the cellular response to stress and in physiological processes modulated by GJIC. Conclusion: HuR promotes gap junctional intercellular communication in rat liver epithelial cells through two related regulatory processes, by enhancing the expression of Cx43 and by increasing the expression of β-catenin, which, in turn, interacts with Cx43 and is required for proper positioning of Cx43 at the plasma membrane. (Hepatology 2009.)