bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Important Precipitation Process Parameters on the Redispersion Process and the Micromechanical Properties of Precipitated Silica
Authors: Schilde C. , Gothsch T. , Quarch K. , Kind M. , Kwade A. 
Published: July 2009

AbstractIn the past, the importance of the industrial mass production of high‐quality products and specialty chemicals by precipitation increased rapidly. In the industry, usually larger aggregates are produced and in order to produce colloidal systems with the desired properties, a more or less intense dispersion of the precipitated particles is necessary. The micromechanical properties such as the maximum indentation force, the plastic and elastic deformation energy, and the strength can give information on the product and the efficiency of the dispersion process. Generally, the temperature, as one of the most important parameters of the semi‐batch precipitation process of silica, was varied in order to change the structure, the primary particle size, the aggregate size, and the primary particle interactions in the aggregates. Dispersion of the precipitated silica in a stirred media mill and a dissolver show that the higher the precipitation temperature, the higher is the product fineness and, thus, the smaller is the strength of the aggregates. The reason for this effect is the increase of the primary particle size and the decrease of the solid bonds with increasing precipitation temperature. Because of higher stress intensities, the product fineness in a stirred media mill is considerably higher than in the dissolver. In principal, the maximum achievable product fineness and the energy efficiency of the dispersion process increase with decreasing particle strength and maximum indentation force. Besides the maximum indentation force, the maximum achievable product fineness and the energy efficiency of the dispersion process increase with increasing quotient of plastic and elastic deformation energy.
Ionic Liquids in Oxygen Compression
Authors: Predel T. , Schlücker E. 
Published: July 2009

AbstractIonic liquids are still a relatively new and very promising class of substances which have received increased research attention in recent years. Due to their unique physical and chemical properties these compounds are ideal for use in industrial applications and also offer a variety of very interesting possibilities in process technology, with a high potential of increasing performance and reducing investment and operating costs [1]. Ionic liquids are remarkable for their high chemical inertness and good lubricity. Therefore, one very promising application is the lubricated compression of oxygen as an alternative to the dry compression technique that has to be used because of the extremely high reactivity of pure oxygen with organic lubricating media. A screening of the relevant parameters including thermal stability, flammability, chemical inertness to pure oxygen, corrosiveness, tribological behavior and oxygen solubility was performed. Based on the results obtained, the most suitable ionic liquid was identified and used in a screw compressor setup that achieves a final pressure of 30 bar with a delivery volume of up to 200 Nm3/h.
The Controlled Formation and Cleavage of an Intramolecular d8–d8 Pt–Pt Interaction in a Dinuclear Cycloplatinated Molecular “Pivot‐Hinge”
Authors: Koo Chi‐Kin , Wong Ka‐Leung , Lau Kai‐Cheung , Wong Wai‐Yeung , Lam Michael Hon‐Wah 
Published: June 2009

AbstractThe bis(diphenylphosphino)methane (dppm)‐bridged dinuclear cycloplatinated complex {[Pt(L)]2(μ‐dppm)}2+ (Pt2⋅dppm; HL: 2‐phenyl‐6‐(1H‐pyrazol‐3‐yl)‐pyridine) demonstrates interesting reversible “pivot‐hinge”‐like intramolecular motions in response to the protonation/deprotonation of L. In its protonated “closed” configuration, the two platinum(II) centers are held in position by intramolecular d8–d8 Pt–Pt interaction. In its deprotonated “open” configuration, such Pt–Pt interaction is cleaved. To further understand the mechanism behind this hingelike motion, an analogous dinuclear cycloplatinated complex, {[Pt(L)]2(μ‐dchpm)}2+ (Pt2⋅dchpm) with bis(dicyclohexylphosphino)methane (dchpm) as the bridging ligand, was synthesized. From its protonation/deprotonation responses, it was revealed that aromatic π–π interactions between the phenyl moieties of the μ‐dppm and the deprotonated pyrazolyl rings of L was essential to the reversible cleavage of the intramolecular Pt–Pt interaction in Pt2⋅dppm. In the case of Pt2⋅dchpm, spectroscopic and spectrofluorometric titrations as well as X‐ray crystallography indicated that the distance between the two platinum(II) centers shrank upon deprotonation, thus causing a redshift in its room‐temperature triplet metal–metal‐to‐ligand charge‐transfer emission from 614 to 625 nm. Ab initio calculations revealed the presence of intramolecular hydrogen bonding between the deprotonated and negatively charged 1‐pyrazolyl‐N moiety and the methylene CH and phenyl C–H of the μ‐dppm. The “open” configuration of the deprotonated Pt2⋅dppm was estimated to be 19 kcal mol−1 more stable than its alternative “closed” configuration. On the other hand, the open configuration of the deprotonated Pt2⋅dchpm was 6 kcal mol−1 less stable than its alternative closed configuration.
A Study of the Influence of Ionic Liquids Properties on the Kemp Elimination Reaction
Authors: D'Anna Francesca , La Marca Sandra , Lo Meo Paolo , Noto Renato 
Published: June 2009

AbstractThe morpholino‐induced elimination of 5‐nitrobenzisoxazole into the relevant 2‐cyano‐4‐nitrophenolate has been used as a sample reaction in order to investigate molecular properties of some room temperature ionic liquids. The kinetic study was carried out at 298 K by means of spectrophotometric measurements. Ionic liquids, which differ in both their cation and anion properties, were used as solvent systems. In particular, aliphatic (pyrrolidinium, piperidinium, and ammonium) and aromatic (imidazolium and pyridinium) ionic liquids were used. For aromatic cations, imidazolium ions having different hydrogen‐bond donor ability or a different alkyl‐chain length were taken into account. The anions chosen ([BF4−], [PF6−], [SbF6−], and [NTf2−]; where NTf2=bis(trifluoromethansulfonyl)imide) showed different shape, size, and coordination ability. Solvent parameters of all ionic liquids used were determined by using spectroscopic probes, such as 4‐nitroaniline, N,N‐diethyl‐4‐nitroaniline, Nile Red, and Reichardt’s dye. Finally, in order to obtain information on the structural organization of the solvent systems, resonance light‐scattering measurements were carried out. The collected data provide evidence that ionic liquids are solvent media which exhibit peculiar features, whose effects can be rationalized only considering all parameters affecting their three‐dimensional structure.
Lanthanide(III) Complexes with Two Hexapeptides Incorporating Unnatural Chelating Amino Acids: Secondary Structure and Stability
Authors: Cisnetti Federico , Gateau Christelle , Lebrun Colette , Delangle Pascale 
Published: June 2009

AbstractUnnatural metal‐chelating amino acids bearing aminodiacetate side‐chains have been introduced into two hexapeptides to obtain efficient lanthanide‐binding peptides. The synthesis of the enantiopure Fmoc‐Adan(tBu)2‐OH synthons is described with overall yields of 32 and 50 % forn=2 andn=3 side‐chain carbon atoms, respectively. The two peptides AcWAdanPGAdanGNH2(Pn) were synthesized from the protected synthons by standard solid‐phase peptide synthesis. Studies of the lanthanide complexes of the two peptidesPnby luminescence titrations, mass spectrometry, circular dichroism, and solution NMR spectroscopy demonstrate that the Adanchain length has a dramatic effect on the complexation properties. Indeed, the flexible compoundP3forms a mononuclear complex of moderate stability (β11=109.9), which tends to transform into a binuclear species in the presence of excess of the metal ion. Interestingly, the more compact peptideP2provides stable Ln3+complexes with the exclusive formation of the mononuclear LnP2adduct. The stability constant of TbP2is two orders of magnitude higher (β11=1012.1) than that measured forP3. The 800 MHz NMR spectrum of the La3+complex ofP2evidences a well‐defined type II β‐turn as well as a hydrophobic Trp(indole)–Pro interaction. These interactions exemplify the non‐innocent character of the peptide spacer in the complex LaP2as well as the role of a peptide secondary structure in the stabilization of metal complexes.
A Straightforward Total Synthesis of (−)‐Chaetominine
Authors: Malgesini Beatrice , Forte Barbara , Borghi Daniela , Quartieri Francesca , Gennari Cesare , Papeo Gianluca 
Published: June 2009

AbstractA total synthesis of the tripeptide alkaloid (−)‐chaetominine (1) was achieved in 9.3 % overall yield starting from commercially available D‐tryptophan methyl ester, based on a short and straightforward (nine steps) sequence. The early stage introduction (first step) of the quinazolinone moiety and the late stage introduction (penultimate step) of the hydroxy group allowed a synthetic strategy devoid of protective groups. The key step of the process is the a–c tricyclic ring construction via an unprecedented NCS‐mediated N‐acyl cyclization on an indole ring to give tetrahydro‐1H‐pyrido[2,3‐b]indole 11. In the penultimate step, oxidation of the tetracyclic intermediate 14 with oxaziridine 15 gave only one of the four possible diastereoisomers, the cis‐diastereoisomer 16 resulting from the attack of the oxaziridine to the double bond face opposite to the c–d ring substituents. In the last step, the complete stereocontrol of the Et3SiH/TFA reduction of compound 16, probably involving a N‐acyliminium ion, can be attributed to ring constrain, which forces the b–c ring junction in the more stable cis‐orientation. (−)‐Chaetominine (1) showed a negligible inhibitory activity on several cancer cell lines.
Feinstäube und Umweltzonen#
Authors: Zellner R. , Kuhlbusch T. A. J. , Diegmann V. , Herrmann H. , Kasper M. , Schmidt K.‐G. , Dott W. , Bruch J. 
Published: June 2009

AbstractUmweltzonen zum Schutz der Bevölkerung vor den gesundheitsschädigenden Auswirkungen der Feinstaubbelastung sind zum Alltagsbild vieler deutscher Großstädte geworden. Nach gut einem Jahr ihrer Einrichtung werden sie von den Befürwortern gelobt und von den Gegnern nach wie vor abgelehnt. Eine Gruppe von Experten aus dem Arbeitsausschuss „Feinstäube”︁ von ProcessNet, KRdL und GDCh hat sich kürzlich mit den Grundlagen der Feinstaubbelastung und ihrer Wirkung befasst und die Sinnhaftigkeit von Umweltzonen unter wissenschaftlichen Aspekten überprüft. Danach sind Umweltzonen durchaus sinnvoll. Die verwendete Metrik eines rein massenbezogenen Grenzwertes ist aus zahlreichen epidemiologischen Untersuchungen wirkungsseitig abgeleitet, jedoch nicht toxikologisch begründet. Der Expertenkreis befürwortet deshalb wirkungsbezogene Forschungen, in denen die Relevanz anderer Partikelmetriken, wie die chemische Zusammensetzung, Größe und Oberfläche, für die menschliche Gesundheit geklärt wird.
MS Binding Assays—with MALDI toward High Throughput
Authors: Höfner Georg , Merkel Dietrich , Wanner Klaus Theodor 
Published: June 2009

AbstractA novel type of MS binding assay, a substitute for radioligand binding, in which the quantification of the MS marker is performed by MALDI‐MS–MS (FlashQuant) has been established. Because conventional MS binding assays can only be carried out by LC–ESI‐MS–MS, the use of the FlashQuant system substantially increases the throughput capacity of this method. The study was performed for mGAT1 as a model system. First, a method was developed to quantify NO 711 as a marker for mGAT1 in a range from 208 pMto 16.7 nMusing [2H10]NO 711 as an internal standard. On this basis, MS binding assays for mGAT1 could be implemented. Affinity constants determined in both saturation and competition experiments were in excellent agreement with those obtained in MS binding assays based on LC–ESI‐MS–MS quantification. As the MALDI‐MS system takes only a few seconds for quantification per sample, and the whole assay procedure is executed in a 96‐well format, this technique is amenable to high‐throughput screening.
Oxygen‐Ion Transport in a Dual‐Phase Scandia–Yttria‐Stabilized Zirconia Solid Electrolyte: A Molecular Dynamics Simulation
Authors: Chang Kai‐Shiun , Tung Kuo‐Lun 
Published: June 2009

AbstractA molecular dynamics (MD) simulation is adopted to investigate oxygen‐ion diffusion mechanisms in dual‐phase (cubic/monoclinic phase) zirconia‐based solid electrolytes. XRD analysis is performed to validate the phase structure composition after an MD duration of 500 ps. The radial distribution function of the ion pairs is used to analyze the microstructure and mobility of the oxygen ions inside the electrolyte. The mean‐squared displacement, displacement distribution, and moving path of oxygen ions indicate that ion mobility increases with Sc2O3 content. Furthermore, the mobility of oxygen ions is relatively lower in the dual‐phase solid‐electrolyte models than in the pure cubic models. This is due to their intrinsically unfavorable configuration for ion penetration. Comparison of the diffusion coefficient and ionic conductivity of the oxygen ions in various phase compositions shows an obvious effect of phase composition complexity in the systems with high Sc2O3 concentration. The introduction of the dual‐phase composition concept for the MD simulation of oxygen‐ion conduction behavior is a promising approach to obtaining a more realistic understanding of ion transport in a solid electrolyte.
Pharmacological efficacy and safety profile of taranabant in preclinical species
Authors: Fong T.M. , Shearman L.P. , Stribling D.S. , Shu J. , Lao J. , Huang C.R.‐R. , Xiao J.C. , Shen C.‐P. , Tyszkiewicz J. , Strack A.M. , DeMaula C. , Hubert M.‐F. , Galijatovic‐Idrizbegovic A. , Owen R. , Huber A.C. , Lanning C.L. 
Published: July 2009

AbstractTaranabant is a highly selective and potent cannabinoid CB1receptor inverse agonist. We compared the pharmacological properties of taranabant with another inverse agonist, rimonabant, and determined the preclinical safety margins of taranabant. In vitro studies demonstrated that taranabant is ∼10‐fold more potent than rimonabant at the CB1receptor, and taranabant is more selective based on off‐target in vitro screening. In vivo efficacy studies demonstrated that taranabant is ∼10‐fold more potent than rimonabant in diet‐induced obese rats. In repeat‐dose toxicological studies, taranabant did not cause mortality in rodents and monkeys at exposure margins ≤6478 and 1922 times the estimated human exposure at 0.5 mg/day−1. Taranabant did not produce CNS signs, including seizures, when administered to monkeys for 1 year at 10 mg/kg−1day−1(highest dose tested chronically), corresponding to an exposure margin of 974 times. In contrast to primates, taranabant produced brief handling‐induced seizure‐like activity in rodents, species predisposed to handling‐induced seizures. Throughout the entire preclinical program, taranabant did not cause histopathological changes in the peripheral or central nervous system. In summary, the highly selective nature of taranabant is consistent with its generally favorable preclinical safety profile. Drug Dev Res 2009. © 2009 Wiley‐Liss, Inc.
Processing of urea‐formaldehyde‐based particleboard from hazelnut shell and improvement of its fire and water resistance
Authors: Gürü M. , Aruntaş Y. , Tüzün F. N. , Bilici İ. 
Published: July 2009

AbstractThe purpose of this study was to manufacture urea‐formaldehyde‐based particleboard from hazelnut shell and eliminate its disadvantages such as flammability, water absorption, swelling thickness by using fly ash and phenol‐formaldehyde. Synthesized urea‐formaldehyde and grained hazelnut shells were blended at different ratios ranging from 0.8 to 3.2 hazelnut shell/urea‐formaldehyde and dried at 70°C in an oven until constant weight was reached. In addition, other parameters affecting polymer composite particleboard from hazelnut shell and urea‐formaldehyde were investigated to be the amount of fly ash, amount of phenol formaldehyde and the effects of these parameters on bending stress, limit oxygen index, water absorption capacity and swelling in the thickness. The optimization results showed that the maximum bending strength was 4.1N/mm2, at urea‐formaldehyde ratio of 1.0, reaction temperature of 70°C, reaction time of 25 min, hazelnut shell/urea‐formaldehyde resin of 2.4 and mean particle size of 0.1 mm. Although the limited oxygen index and smoke density of composite particleboard without fly ash has 22.3 and 1.62, with fly ash of 16% (w/w) according to the filler has 38.2 and 1.47, respectively. Water absorption and increase in the swelling thickness exponentially decreased with increasing phenol formaldehyde. Copyright © 2009 John Wiley & Sons, Ltd.
Cyclic αvβ6‐targeting peptide selected from biopanning with clinical potential for head and neck squamous cell carcinoma
Authors: Hsiao Jenn‐Ren , Chang Yao , Chen Yuh‐Ling , Hsieh Su‐Huei , Hsu Keng‐Fu , Wang Chun‐Fu , Tsai Sen‐Tien , Jin Ying‐Tai 
Published: July 2009

AbstractBackground.A cyclic peptide‐displaying phage library was used for biopanning on oral squamous cell carcinoma (OSCC) cells to identify cancer‐targeting peptides. This study was designed to characterize the receptor specificity of a candidate phage clone/peptide (phage/peptide‐29) and to explore the clinical potential of this peptide.Methods.Immunofluorescent confocal microscopy, phage binding assay, and immunohistochemical studies were used to demonstrate the receptor specificity of phage/peptide‐29. The effect of peptide‐29 on the proliferation of OSCC cells was studied using 3‐dimensional (3D) cell cultures.Results.Phage/peptide‐29 preferentially binds integrin αvβ6 rather than other αv‐associated integrins. Peptide‐29 significantly inhibits the proliferation of OSCC cells in 3D cell cultures. On human pathological sections, phage‐29 targets oral cancer cells in a αvβ6‐dependent manner. Besides, we showed that integrin αvβ6 is universally (94.7%, 36/38) expressed in all major kinds of head and neck squamous cell carcinomas (HNSCC).Conclusions.Peptide‐29 selected from biopanning may have clinical potential for HNSCC. © 2009 Wiley Periodicals, Inc. Head Neck, 2010
Evaluation of salt sources and loads in the upland areas of the Murray–Darling Basin, Australia
Authors: White Ian , Macdonald Ben C. T. , Somerville Peter D. , Wasson Robert 
Published: July 2009

AbstractEstimates of catchment salt balances throughout the Murray‐Darling Basin (MDB) suggest mobilization of salt stores and generally increasing stream salinities. It is widely assumed these salts are rainfall‐deposited cyclic salts of marine‐aerosol origin, concentrated by evapotranspiration, stored in groundwaters and mobilized by clearing of native vegetation. In this paper, the assumptions about the sources of salts, in upland catchments in the south‐eastern region of the MDB are re‐evaluated. The estimation of dissolved salts is re‐examined using electrical conductivity (EC), the assessment of stream salt loads from sporadic EC measurements and the sources of salts in upland catchments. It is concluded that, although evapotranspiration plays a significant role in the concentrations of salts in the lower MDB, mineral weathering is a major contributor to stream salt loads in upland rivers of the MDB that supply over 80% of surface runoff to the Murray River. Copyright © 2009 John Wiley & Sons, Ltd.
Transient storage and downstream solute transport in nested stream reaches affected by beaver dams
Authors: Jin Li , Siegel Donald I. , Lautz Laura K. , Otz Martin H. 
Published: July 2009

AbstractTransient storage constitutes a key element in the hydrologic cycle of watersheds. Both in‐channel slow moving water (dead zones) and hyporheic zones can contribute to transient storage, which retains water and solutes, increases residence time and influences solute transport in streams. Beaver dams and other in‐stream obstructions throughout low‐order streams attenuate streamflow and provide dead zone storage in pools. In this article, we report the results of four tracer tests in nested stream reaches in Cherry Creek (Wyoming, USA) covering ∼2·5 km of stream length to explore how the degree of beaver dam obstructions and their impoundments influence water transient storage and downstream solute transport in low‐order streams in the Rocky Mountain region of the American West. Travel‐time parameters for the tracer tests increased linearly with beaver dam number (N) and pond size (V). Linear regression of the travel time to the peak concentration (Tp), the leading (Tl) and tailing edge (Tt) of the dye cloud and the duration of the dye cloud (Td) versus N and V were all significant (R2 = 0·99). Slopes of the linear regressions of Tt versus N and V, were three times larger than those for Tl, suggesting that longer residence times may be caused, in part, by transient storage in the stream system. One‐dimensional transport with inflow and storage (OTIS) modelled cross‐sectional area of transient storage zone (As) and dispersion coefficients (D) increased linearly with N and V and reach length. Two transient storage metrics, Fmean and $F_{\rm {med}}^{200}$, also showed a general increase with N and V, although the relationship was not as strong. This suggests that in‐channel dead zones associated with beaver dams provide opportunities for generating transient water storage. The linear relationship between dispersion coefficient and reach length suggests the dispersion process might be analogous to the hydrodynamic dispersion in groundwater settings. Copyright © 2009 John Wiley & Sons, Ltd.
The predictive value of different infant attachment measures for socioemotional development at age 5 years
Authors: Smeekens Sanny , Riksen‐Walraven J. Marianne , Van Bakel Hedwig J.A. 
Published: July 2009

AbstractThe predictive value of different infant attachment measures was examined in a community‐based sample of 111 healthy children (59 boys, 52 girls). Two procedures to assess infant attachment, the Attachment Q‐Set (applied on a relatively short observation period) and a shortened version of the Strange Situation Procedure (SSSP), were applied to the children at age 15 months and related to a comprehensive set of indicators of the children's socioemotional development at age 5 years. Three attachment measures were used as predictors: AQS security, SSSP security, and SSSP attachment disorganization. AQS security and SSSP security jointly predicted the security of the children's attachment representation at age 5. Apart from that, SSSP attachment disorganization was a better predictor of the children's later socioemotional development than were the other two early attachment measures. First, attachment disorganization was the only attachment measure to predict the children's later ego‐resiliency, school adjustment, and dissociation. Second, as for the socioemotional measures at age 5 that also were related to AQS or SSSP security (i.e., peer social competence and externalizing problems), the attachment security measures did not explain any extra variance beyond what was explained by attachment disorganization.