bluuebunny/crossref_metadata_2025_split huggingface dataset:
Green Catalysts: Solid‐Phase Peptide Carbene Ligands in Aqueous Transition‐Metal Catalysis
Authors: Worm‐Leonhard Kasper , Meldal Morten 
Published: September 2008

AbstractA series of functionalized imidazolium ions containing a pyridine moiety and carboxylic acid functionality has been synthesized in solution. These compounds serve asN‐heterocyclic carbene precursors and were attached to a dipeptide on solid support by means of standard peptide coupling techniques. Treatment with base generated the corresponding carbenes, which were directly complexed to palladium(II) and subsequently studied by mass spectrometry and NMR spectroscopy. The supported monocarbene catalyst7was successfully applied in Sonogashira and Suzuki cross‐coupling reactions, and the cross‐coupling products were isolated in excellent yield. Bis(carbene) catalyst8was successfully applied in solution in high‐yielding Suzuki cross‐coupling reactions. Furthermore, the catalysts proved to be stable in aqueous media, which allowed the Suzuki cross‐coupling reactions to be performed in water. No loss of catalytic activity was observed when supported catalyst7was recycled and subjected to repetitive cycles of Suzuki cross‐coupling reactions in water.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Nα‐Fmoc‐Protected ω‐Azido‐ and ω‐Alkynyl‐L‐amino Acids as Building Blocks for the Synthesis of “Clickable” Peptides
Authors: Le Chevalier Isaad Alexandra , Barbetti Francesca , Rovero Paolo , D'Ursi Anna Maria , Chelli Mario , Chorev Michael , Papini Anna Maria 
Published: September 2008

AbstractThe growing interest in the 1,4‐disubstituted‐1,2,3‐triazolyl moiety as an amide bond surrogate and its formation through very mild, chemoselective, and bioorthogonal CuI‐catalyzed Huisgen 1,3‐dipolar [3+2] cycloaddition of an alkynyl to an azido function, presented an unmet need for specifically designed α‐amino‐acid‐derived building blocks. Herein we report the synthesis of unnatural homologous series of Nα‐Fmoc‐protected ω‐yne‐ and ω‐azido‐L‐amino acids compatible with the Fmoc/tBu‐based solid‐phase peptide synthesis. These building blocks can be incorporated into pseudopeptides that can serve as precursors of inter‐ and intramolecular click reactions. The homologous Nα‐Fmoc‐ω‐azido‐L‐amino acids were prepared from either the ω‐amino or the ω‐hydroxy precursors by the respective diazo‐transfer reactions and sequential nucleophilic substitutions initially by halide followed by azide. The homologous Nα‐Fmoc‐ω‐yne‐L‐amino acids were prepared by alkylation of a chiral auxiliary, which is a NiII complex of Schiff base derived from glycine and (S)‐2‐(N‐benzylprolyl)aminobenzophenone, with ω‐bromoalkynes. These building blocks will be instrumental for constructing side‐chain modified peptides, interside‐chain peptide chimera, peptide small molecule conjugates, and cyclopeptides, which were cyclized through 1,4‐disubstituted 1,2,3‐triazolyl‐containing side‐chain‐to‐side‐chain bridges. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Nucleophilic Trifluoromethylation of Imines under Acidic Conditions
Authors: Levin Vitalij V. , Dilman Alexander D. , Belyakov Pavel A. , Struchkova Marina I. , Tartakovsky Vladimir A. 
Published: September 2008

AbstractA general method for the trifluoromethylation of imines by using Me3SiCF3 under acidic conditions is described. The reaction is promoted by hydrofluoric acid generated in situ from KHF2 and either TFA or TfOH. A new chemoselectivity pattern was achieved, as the C=N bond was found to be more reactivate than the carbonyl group. The trifluoromethylation reaction is believed to proceed by concerted transfer of the CF3 group from the silicon atom to the iminium electrophile. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
The Intermolecular Pauson–Khand Reaction of meso‐Substituted Porphyrins (Eur. J. Org. Chem. 29/2008)
Authors: Horn Sabine , Senge Mathias O. 
Published: September 2008

AbstractThe cover picture shows the products of the intermolecular Pauson–Khand reaction of meso‐substituted porphyrins. In addition to various monomers, this method offers easy access to porphyrin dimers with well‐defined stereochemistries. Details are discussed in the article by S. Horn and M. O. Senge from Trinity College Dublin on p. 4881 ff.
Probabilistic risk modeling at the wildland urban interface: the 2003 Cedar Fire
Authors: Brillinger D. R. , Autrey B. S. , Cattaneo M. D. 
Published: September 2008

AbstractThe October 2003 Cedar Fire in San Diego County was a tragedy involving 15 deaths, the burning of some 280 000 acres of land, the destruction of approximately 2227 homes, and costs of suppression near $30 million. It was the largest fire in California history. The data associated with the fire, however, do provide an opportunity to carry out probabilistic risk modeling of a wildland‐urban interface (WUI) event. WUI's exist where humans and their development interface with wildland fuel. As home building expands from urban areas to nearby forest areas, these homes become more likely to burn.Wildfires are an exceedingly complex phenomenon with uncertainty and unpredictability abounding, hence a statistical approach to gaining insight appears useful. In this research, spatial stochastic models are developed. These relate risk probabilities and losses measures to a variety of available explanatory quantities. There is a consideration of economic aspects and a discussion of the difficulties that arose in developing the data and of carrying out the analyses. Purposes of the work include highlighting a statistical method, developing variates associated with a destruction probability and employing the fitted risk probability to estimate future and possible losses. Copyright © 2008 John Wiley & Sons, Ltd.
Long‐term stability of biological denitrification process for high strength nitrate removal from wastewater of uranium industry
Authors: Biradar Prashant M. , Dhamole Pradip B. , Nair Rashmi R. , Roy S.B. , Satpati S.K. , D'Souza Stanislaus F. , Lele S.S. , Pandit A.B. 
Published: September 2008

AbstractThe aim of the present study was to biologically denitrify uranium nitrate raffinate (UNR) from nuclear industry, which is a principle source of high strength nitrate waste. To denitrify the high nitrate waste, a pilot‐scale continuous stirred tank reactor was designed with two inbuilt settlers. Acclimatization of mixed culture with synthetic waste was carried out prior to the inoculation of the acclimatized sludge into the reactor. Initial concentration of nitrate in uranium raffinate was 77,000 mg/L NO3. It was diluted and used as a feed to the reactor. Concentration of nitrate in feed was increased gradually from 10,000 mg/L NO3 to 40,000 mg/L NO3 with hydraulic retention time (HRT) maintained at 34.4 h. Complete denitrification of 40,000 mg/L NO3 was achieved in a specified HRT.To facilitate understanding of the treatablity and long‐term stability of biological denitrification of UNR, study was carried out for 211 days by periodical perturbation of the system. Furthermore, to find the volume ratio of reactor to settler required for the full‐scale design of the denitrification plant, settling of acclimatized sludge was carried out. © 2008 American Institute of Chemical Engineers Environ Prog, 2008
Influence of exhaust hood geometry on the capture efficiency of lateral exhaust and push–pull ventilation systems in surface treatment tanks
Authors: González Enrique , Marzal Francisco , Miñana Agustín , Doval Marta 
Published: September 2008

AbstractIn a local exhaust ventilation system, where the pollutant or the emitted flows are captured near the generated source, the knowledge of the capture efficiency is necessary to evaluate performance. This article reports a study of the influence of the exhaust hood slot height on the capture efficiency. For this study, the emission of gases and vapors from open surface tanks used in industrial treatments has been simulated in an installation fitted with two ventilation systems: lateral exhaust and push–pull. Several configurations were possible by varying the geometrical and operational conditions. Both qualitative and quantitative evaluations have been performed, the former through observations of the flows using smoke and the latter by using sulfur hexafluoride as tracer gas. The results obtained on capture efficiency for both ventilation systems tested with several exhaust slot height and as a function of the operating flows rates, are presented. It was found that varying the exhaust slot height between 15 and 45 cm had no effect on capture efficiency. The results show that there are no significant differences between the exhaust slots heights tested, although, in the case of 60 cm for lateral exhaust ventilation, the efficiency was slightly lower. © 2008 American Institute of Chemical Engineers Environ Prog, 2008
Pollution reduction and energy savings of a coupled two‐kiln system for bricks making
Authors: Chavez Rosa‐Hilda 
Published: September 2008

AbstractAtmospheric pollution is one of the most important current environmental problems, becoming a phenomenon that could reach levels of serious consequences with irreversible environmental impacts. In Mexico, like in several other countries, brickmakers carry out brick production by burning mixtures of different heavy fuels. Because of the wide variety of fuels used, it is necessary to determine what types of residual gases are generated, in order to propose remedial treatments in production or to introduce substitution technologies. These preventive actions need to be put in place in order to comply with the Ecological Balance and Environment Protection Federal Law. Brick kilns emit pollutant gases and particles that remain in the air, causing a serious health hazard to the near‐factory residents. Amongst these pollutants are carbon monoxide (CO), sulfur oxides (SOx), and hydrocarbons. This article presents the results of the analysis of a novel two‐kiln coupled system. This experimental analysis includes the determination of the combustion products for gases and particulate matter generated from the burning of the heavy fuels using gas chromatography and scanning electron microscopy. Field data also allowed the determination of energy savings for this system, mainly because of the reduction of the consumption of fuel. Fortunately, these results show a combined 39% energy savings and a reduction of pollutants and particle emissions, as compared to the standard currently‐in‐use brick‐production systems. © 2008 American Institute of Chemical Engineers Environ Prog, 2008
Blind channel identification in Alamouti coded systems: a comparative study of eigendecomposition methods in indoor transmissions at 2.4 GHz
Authors: Pérez‐Iglesias Héctor J. , García‐Naya José A. , Dapena Adriana , Castedo Luis , Zarzoso Vicente 
Published: September 2008

AbstractThis paper focuses on blind channel estimation in Alamouti coded systems with one receiving antenna working in indoor scenarios where the flat fading assumption is reasonable. A comparative study of several channel estimation techniques in both simulated and realistic scenarios is presented. The tested methods exploit the orthogonality property of the Alamouti coded channel matrix, and are based on the eigendecomposition of a square matrix made up of second‐order statistics (SOS) or higher order statistics (HOS) of the observed signals. An experimental evaluation is carried out on a testbed developed at the University of A Coruña (UDC) and operating at 2.4 GHz. The results show the superior performance of the SOS‐based blind channel estimation technique in both line of sight (LOS) and non‐LOS (NLOS) channels. Copyright © 2008 John Wiley & Sons, Ltd.
Modelling the daily banknotes in circulation in the context of the liquidity management of the European Central Bank
Authors: Cabrero Alberto , Camba‐Mendez Gonzalo , Hirsch Astrid , Nieto Fernando 
Published: September 2008

AbstractThe main focus of this paper is to model the daily series of banknotes in circulation. The series of banknotes in circulation displays very marked seasonal patterns. To the best of our knowledge the empirical performance of two competing approaches to model seasonality in daily time series, namely the ARIMA‐based approach and the Structural Time Series approach, has never been put to the test. The application presented in this paper provides valid intuition on the merits of each approach. The forecasting performance of the models is also assessed in the context of their impact on the liquidity management of the Eurosystem.  Copyright © 2008 John Wiley & Sons, Ltd.
Hippocampal, amygdala, and neocortical synchronization of theta rhythms is related to an immediate recall during rey auditory verbal learning test
Authors: Babiloni Claudio , Vecchio Fabrizio , Mirabella Giovanni , Buttiglione Maura , Sebastiano Fabio , Picardi Angelo , Di Gennaro Giancarlo , Quarato Pier P. , Grammaldo Liliana G. , Buffo Paola , Esposito Vincenzo , Manfredi Mario , Cantore Giampaolo , Eusebi Fabrizio 
Published: September 2008

AbstractIt is well known that theta rhythms (3–8 Hz) are the fingerprint of hippocampus, and that neural activity accompanying encoding of words differs according to whether the items are later remembered or forgotten [“subsequent memory effect” (SME)]. Here, we tested the hypothesis that temporal synchronization of theta rhythms among hippocampus, amygdala, and neocortex is related to immediate memorization of repeated words. To address this issue, intracerebral electroencephalographic (EEG) activity was recorded in five subjects with drug‐resistant temporal lobe epilepsy (TLE), under presurgical monitoring routine. During the recording of the intracerebral EEG activity, the subjects performed a computerized version of Rey auditory verbal learning test (RAVLT), a popular test for the clinical evaluation of the immediate and delayed memory. They heard the same list of 15 common words for five times. Each time, immediately after listening the list, the subjects were required to repeat as many words as they could recall. Spectral coherence of the intracerebral EEG activity was computed in order to assess the temporal synchronization of the theta (about 3–8 Hz) rhythms among hippocampus, amygdala, and temporal‐occipital neocortex. We found that theta coherence values between amygdala and hippocampus, and between hippocampus and occipital‐temporal cortex, were higher in amplitude during successful than unsuccessful immediate recall. A control analysis showed that this was true also for a gamma band (40–45 Hz). Furthermore, these theta and gamma effects were not observed in an additional (control) subject with drug‐resistant TLE and a wide lesion to hippocampus. In conclusion, a successful immediate recall to the RAVLT was associated to the enhancement of temporal synchronization of the theta (gamma) rhythms within a cerebral network including hippocampus, amygdala, and temporal–occipital neocortex. Hum Brain Mapp, 2009. © 2008 Wiley‐Liss, Inc.
Strong resemblance in the amplitude of oscillatory brain activity in monozygotic twins is not caused by “trivial” similarities in the composition of the skull
Authors: van 't Ent Dennis , van Soelen Inge L.C. , Stam Cornelis J. , De Geus Eco J.C. , Boomsma Dorret I. 
Published: September 2008

AbstractPrevious twin studies have shown strong heritability of electroencephalogram amplitude characteristics, such as power spectra. However, it has been suggested that these high heritabilities may reflect “trivial” twin resemblance in intervening tissues such as the skull. Here we demonstrate strong monozygotic twin correlation (0.79 < r < 0.88) of eyes‐closed resting‐state magnetoencephalogram power, which is insensitive to intervening tissues. These results confirm that brain activity itself is highly heritable. Hum Brain Mapp, 2009. © 2008 Wiley‐Liss, Inc.
Extensions to decomposition of the redistributive effect of health care finance
Authors: Zhong Hai 
Published: September 2008

AbstractThe total redistributive effect (RE) of health‐care finance has been decomposed into vertical, horizontal and reranking effects. The vertical effect has been further decomposed into tax rate and tax structure effects. We extend this latter decomposition to the horizontal and reranking components of the RE. We also show how to measure the vertical, horizontal and reranking effects of each component of the redistributive system, allowing analysis of the RE of health‐care finance in the context of that system. The methods are illustrated with application to the RE of health‐care financing in Canada. Copyright © 2008 John Wiley & Sons, Ltd.
Preparation, characterization, and evaluation of radiopaque hydrogel filaments for endovascular embolization
Authors: Constant Michael J. , Keeley Edward M. , Cruise Gregory M. 
Published: September 2008

AbstractRadiopaque hydrogel filaments were prepared, characterized, and evaluated for potential use as implants for endovascular embolization of vascular defects. Three hydrogel formulations were prepared by free radical polymerization: (i) poly(ethylene glycol) diacrylate with 2,4,6‐triiodophenyl penta‐4‐enoate (PEG‐I), (ii) poly(ethylene glycol) diacrylamide with barium sulfate (PEG‐B), and (iii) poly(propylene glycol) diacrylate with barium sulfate (PPG‐B). The PEG‐B and PPG‐B hydrogels exhibited radiopacity comparable with clinically used platinum coils, whereas the PEG‐I hydrogel did not. In the dry state, the average ultimate tensile strength and strain of the hydrogels ranged from 37 to 128 gf and 21% to 72%, respectively. The PEG‐B hydrogel had significantly higher tensile strength compared with the PEG‐I hydrogel. In the hydrated state, the average ultimate tensile strength and strain ranged from 5 to 15 gf and 7% to 30%, respectively. Statistically significant differences in tensile strength were not present when hydrated. Compared with poly(ethylene) after 4‐week implantation into the subcutaneous space of rabbits, the PEG‐I hydrogel elicited slightly more inflammation, whereas the PEG‐B and PPG‐B hydrogels elicited less inflammation. All three hydrogel formulations elicited less fibrous encapsulation than poly(ethylene). With further development, these materials have potential as embolization devices. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Cephalexin‐loaded injectable macroporous calcium phosphate bone cement
Authors: Hesaraki Saeed , Nemati Roghayeh 
Published: September 2008

AbstractDifferent types of calcium phosphate cements (CPCs) have been studied as potential matrices for incorporating different types of antibiotics. All of these matrices were morphologically microporous whereas macroporosity is essential for rapid cement resorption and bone replacement. In this study, liberation of cephalexin monohydrate (CMH) from a macroporous CPC was investigated over 0.5–300 h in simulated body fluid and some mathematical models were fitted to the release profiles. Macroporosity was introduced into the cement matrix by using sodium dodecyl sulfate molecules as air‐entraining agents and the effect of both surfactant and CMH on basic properties of the CPC was studied. Incorporation of CMH into the CPC composition increased the setting time, decreased the crystallinity of the formed apatite phase, and improved the injectability of the paste. The use of both CMH and sodium dodecyl sulfate did not affect the rate of conversion of the reactants into apatite phase while soaking the cements in simulated body fluid. Results showed that the liberation rate of the drug from porous CPC was higher than that of the nonporous CPC but same release patterns were experienced in both types of cements, that is, like to nonporous CPC, a time‐dependent controlled release of the incorporated drug was obtained from macroporous CPC. The Weibull model was the best fitting‐equation for release profiles of all cements. The liberated CMH was as active as fresh cephalexin. It is concluded that this macroporous CPC can be successfully used as drug carrier with controlled release profile for the treatment of bone infections. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Controlling the biodegradation rate of magnesium using biomimetic apatite coating
Authors: Zhang Yajing , Zhang Guozhi , Wei Mei 
Published: September 2008

AbstractMagnesium is light, biocompatible and has similar mechanical properties to natural bone, so it has the potential to be used as a biodegradable material for orthopedic applications. However, pure magnesium severely corrodes in a physiological environment, which may result in fracture prior to substantial tissue healing. Hydroxyapatite (HA) is the main composition of natural bone. It has excellent bioactivity and osteoconductivity. In this study, HA coating with two different thicknesses was applied onto the surface of pure magnesium substrates using a biomimetic technique. The corrosion rate of the surface‐treated substrates was tested. It was found that both types of coatings substantially slowed down the corrosion of the substrate, and the dual coating was more effective than the single coating in hindering the degradation of the substrate. Thus, the corrosion rate of magnesium implants can be closely tailored by adjusting apatite coating thickness and thereby monitoring the release of magnesium ions into the body. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Sphingosine‐1‐phosphate acts as a developmental stage specific inhibitor of platelet‐derived growth factor‐induced chemotaxis of osteoblasts
Authors: Roelofsen T. , Akkers R. , Beumer W. , Apotheker M. , Steeghs I. , van de Ven J. , Gelderblom C. , Garritsen A. , Dechering K. 
Published: September 2008

AbstractThe development and maintenance of a healthy skeleton depends on the migration of cells to areas of new bone formation. Osteoblasts, the bone forming cells of the body, mature from mesenchymal stem cells under the influence of bone morphogenetic protein. It is unclear at what developmental stage the osteoblasts start to migrate to their functional location. We have studied migration of immature pre‐osteoblasts and of mature osteoblasts in response to Platelet‐derived growth factor (PDGF) and sphingosine‐1‐phosphate (S1P). PDGF is a growth factor involved in bone remodeling and fracture healing whereas S1P is a circulating sphingolipid known to control cell trafficking. Our data indicate that PDGF acts as a chemotactic cue for pre‐osteoblasts. In contrast, S1P is a chemorepellent to these cells. Upon Bone Morphogenetic Protein 2‐induced conversion to the osteoblast phenotype, the chemotaxis response to PDGF is retained whereas the sensitivity to S1P is lost. By RNA interference and overexpression experiments we showed that the expression level of the S1P2 receptor is the sole determinant controlling responsiveness to S1P. The combined data indicate that migration of osteoblasts is controlled by the balance between PDGF, S1P and the differentiation state of the cells. We propose that this mechanism preserves the osteoprogenitor pool in the bone marrow, only allowing the more differentiated cell to travel to sites of bone formation. J. Cell. Biochem. 105: 1128–1138, 2008. © 2008 Wiley‐Liss, Inc.