bluuebunny/crossref_metadata_2025_split huggingface dataset:
Use of perfluoro groups in nucleophilic 18F‐fluorination
Authors: Blom Elisabeth , Karimi Farhad , Långström Bengt 
Published: November 2009

AbstractSubstrates with leaving groups that contained perfluoro moieties were investigated in labelling chemistry in order to exploit their properties to improve reactivity and purification. [18F](Fluoromethyl)benzene was used as the model target compound. Precursors containing perfluoroalkyl and perfluoroaryl sulfonate moieties were subjected to nucleophilic 18F‐fluorination, and the impact of perfluoro groups on the substitution reaction and product purification was investigated. [18F]Fluoride interacted with perfluoroalkyl chains, precluding nucleophilic substitution. When perfluoroaryl groups were used, the substitution proceeded, and the separation of product was explored. The radiolabelled product was obtained in 32% analytical yield and the radiochemical purity was increased to approximately 77% using fluorous solid phase extraction purification. Copyright © 2009 John Wiley & Sons, Ltd.
Influence of [2H]‐labelled acetic acid as solvent in the synthesis of [2H]‐labelled perhexiline
Authors: Schou Søren Christian 
Published: November 2009

AbstractPreparation of deuterium‐labelled perhexiline from an unsaturated analogue was performed via reduction with deuterium gas and PtO2 in acetic acid. Low incorporation was observed when using acetic acid as solvent (most abundant mass peak was M), but when changing the solvent to deuterium‐labelled acetic acid, e.g. acetic acid‐OD or acetic acid‐d4, a higher incorporation was observed (most abundant mass peak was M). Using hydrogen gas instead of deuterium gas with deuterium‐labelled acetic acid, high levels of deuterium incorporation were observed (most abundant mass peak was M). An attempt to reduce a precursor with a fully deuterated pyridine to obtain perhexiline with a higher content of deuterium failed. Copyright © 2009 John Wiley & Sons, Ltd.
Preparation and biodistribution of [125I]Melphalan: a potential radioligand for diagnostic and therapeutic applications
Authors: Amin A. M. , Soliman S. E. , El‐Aziz H. A. 
Published: November 2009

AbstractThis paper addresses the development of a new radiopharmaceutical for cancer imaging and therapy. The optimization of the labeling conditions of thymidine analogue, melphalan, with125I is described. High radiochemical yield 96.8% was obtained by reacting 0.2 mg melphalan with 125I in the presence of choloramin‐T as oxidizing agent in 0.5 M phosphate buffer, pH 7, at 70°C for 15 min. Preliminary in vivo study was done in non‐tumor bearing mice. The results revealed that this new tracer,125I‐melphalan, has a high affinity to be localized in the tumor site for a long period, which indicates the specificity of this tracer to the tumor cells. The labeled compound was cleared quickly from most of the body organs. These findings suggest that 125I‐melphalan allows imaging and treatment of cancer. 125I‐melphalan meets most of the requirements necessary to be used as a successful diagnostic and therapeutic agent: it is a low‐molecular‐weight molecule that diffuses readily in the tissues, and dose not induce an antibody response. Copyright © 2009 John Wiley & Sons, Ltd.
Lindlar catalyst mediated tritiation of a triazole substituted isoxazoline insecticide
Authors: Rauh James J. , Lahm George P. , Pahutski Thomas F. , Ullas Giliyar V. , Filer Crist N. 
Published: November 2009

AbstractThe radiolabelling of isoxazoline insecticide 1a employing a Lindlar catalyst tritium dehalogenation of a bromo precursor is described. Copyright © 2009 John Wiley & Sons, Ltd.
Molecular recognition of RNA: challenges for modelling interactions and plasticity
Authors: Fulle Simone , Gohlke Holger 
Published: November 2009

AbstractThere is growing interest in molecular recognition processes of RNA because of RNA's widespread involvement in biological processes. Computational approaches are increasingly used for analysing and predicting binding to RNA, fuelled by encouraging progress in developing simulation, free energy and docking methods for nucleic acids. These developments take into account challenges regarding the energetics of RNA–ligand binding, RNA plasticity, and the presence of water molecules and ions in the binding interface. Accordingly, we will detail advances in force field and scoring function development for molecular dynamics (MD) simulations, free energy computations and docking calculations of nucleic acid complexes. Furthermore, we present methods that can detect moving parts within RNA structures based on graph‐theoretical approaches or normal mode analysis (NMA). As an example of the successful use of these developments, we will discuss recent structure‐based drug design approaches that focus on the bacterial ribosomal A‐site RNA as a drug target. Copyright © 2009 John Wiley & Sons, Ltd.
Thermodynamic and structural analysis of interactions between peptide ligands and SEB
Authors: Dudak Fahriye Ceyda , Soykut Esra Acar , Oğuz Murat Erman , Yaşar Fatih , Boyacı İsmail Hakkı 
Published: November 2009

AbstractStaphylococcal enterotoxin B (SEB) is an exotoxin produced by Staphylococcus aureus and commonly associated with food poisoning. In this study, SEB‐binding peptides were identified by screening a phage displayed peptide library. The binding of peptides to SEB was tested with isothermal titration calorimetry (ITC) and of the five selected peptides, three showed affinity to SEB, with one measured to have the highest affinity constant (105 M−1). ITC revealed that the interaction of peptide ligands with SEB was driven entropically and the binding was dominated by hydrophobic interactions. Circular dichroism (CD) measurements and molecular dynamics (MD) simulations, together, give a structural insight into the interaction of peptides with SEB. While SEB binding peptides showed random coil structure before binding, after complex formation they had more ordered structures. The peptide with highest affinity to SEB showed stable conformation during MD simulation. Taken together, our approach about thermodynamic and structural characterization of peptide ligands can be used to develop aptamers, with high affinity and selectivity, for biosensor applications. Copyright © 2009 John Wiley & Sons, Ltd.
What can isothermal titration microcalorimetry experiments tell us about the self‐organization of surfactants into micelles?
Authors: Bouchemal Kawthar , Agnely Florence , Koffi Armand , Djabourov Madeleine , Ponchel Gilles 
Published: November 2009

AbstractThe aim of the present review is to give a concise analysis of the thermodynamic parameters obtained from isothermal titration microcalorimetry (ITC) experiments for the characterization of the self‐organization of surfactants into micelles. This review is also focused on works describing some methods allowing to overcome ITC limitation and to extract accurate thermodynamic values from ITC data. Copyright © 2009 John Wiley & Sons, Ltd.
A test of CoupModel for assessing the nitrogen leaching in grassland systems with two different fertilization levels
Authors: Conrad Yvonne , Fohrer Nicola 
Published: November 2009

AbstractLand‐use and crop‐biomass development influence water and nutrient dynamics in soils. Nitrate‐N leaching rises with increasing mineral‐N input during seepage periods in sandy soils. Leaching of N was simulated for two grassland treatments (N0: unfertilized; N300: highly fertilized: 300 kg mineral N ha–1 y–1) using CoupModel. Parameter uncertainty was considered by an automated calibration based on the General Likelihood Uncertainty Estimation (GLUE) approach. The results of this optimization approach showed a realistic reproduction of abiotic and biotic patterns of the system. Modeled abiotic parameters, i.e., soil temperatures and water contents in different soil depths, led to plausible results with minor differences between fertilization levels and some respect for discrepancies due to heterogeneous soil conditions. Groundwater levels were slightly underestimated by CoupModel with a smoother dynamic than measured in both treatments. CoupModel provided plausible results for nitrate‐N concentrations below the rooting zone at 60 cm depth with higher uncertainty ranges than standard deviations of the measurements. Simulated nitrate‐N concentrations of the unfertilized grassland confirmed the measurements, and no potential environmental risk for water bodies existed according to the standards of the European Drinking Water Directive. The model reproduced satisfactorily the observations for the N300 system with a slightly overestimation in 40% of the simulated seepage periods. Higher uncertainties were found for the simulated N300 than for the N0 plot. Modeled N flows below the rooting zone of 11 kg nitrate‐N ha–1 per seepage period were comparable to calculations of the model “Büchter” with a mean of 10 kg nitrate‐N ha–1. For the N300 plot, a more than twice as high N‐leaching amount of 74 kg nitrate‐N ha–1 was modeled compared to a calculated average of 30 kg nitrate‐N ha–1. Finally, small‐scale modeling can provide plausible results for nitrate‐N leaching on plot‐scale when uncertainties in soil water, N flows, and biomass growth are considered.
An assessment of the impact of climate change on evapotranspiration, groundwater recharge, and low‐flow conditions in a mesoscale catchment in Northeast Germany
Authors: Wegehenkel Martin , Kersebaum Kurt‐Christian 
Published: November 2009

AbstractFuture climate changes might have some impacts on the discharge regime of rivers in Germany regarding, e.g., longer low‐flow periods in summer months due to a decreased precipitation and increased evapotranspiration. During such low‐flow periods, water temperature increases leading to a reduced oxygen concentration and a decrease in water quality. An assessment of such impacts is required to derive adaptation strategies for future water‐resources management. The main objective of our study was to obtain an estimation of the impact of projected future climate change on evapotranspiration, groundwater recharge, and low‐flow conditions. For that purpose, we applied a hydrological catchment model in the Ucker catchment with an area of 2415 km2 located in the lowlands of NE Germany using meteorological time series from 1951 to 2055. These time series were generated by the Potsdam Institute of Climate Impact Research based on the A1B‐Scenario with an increase of 1.4°C of the mean annual temperature and a mean decrease of 8% in annual rates of precipitation. After model calibration, the comparison of simulated and observed daily discharge rates from 1989 to 2003 led to a Nash‐Sutcliffe‐Index NS = 0.63. The results of this simulation study indicated that the amount of days with low‐flow conditions in the Ucker river will increase and groundwater recharge especially at forested areas will decrease in an order of magnitude of 1%–94%.
Do reactive oxygen species (ROS) induced by NaCl contribute to ammonium accumulation in Spartina alterniflora?
Authors: Hessini Kamel , Cruz Cristina , Gandour Mhemmed , Soltani Abdelaziz , Abdelly Chedly 
Published: November 2009

AbstractGrowth, activity of antioxidant enzymes viz. glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and guaiacol peroxidase (GPX), and some metabolic processes related to ammonium metabolism were investigated in a salt‐tolerant Spatina alterniflora. In comparison to 0 mM–NaCl treatment, growth of S. alterniflora plant increased significantly at 200 mM NaCl, but was highly inhibited at 500 mM NaCl. Ammonium concentration in the leaves and roots increased 2.1–3.4 times when plants were treated with 500 mM NaCl. Under 200 mM NaCl, antioxidant‐enzyme activities increased, however, at 500 mM the antioxidant system was unable to compensate reactive oxygen species induced by NaCl. At this high level of salinity, ammonium production through nitrate reductase (NR) was inhibited, but no significant changes in the activities of glutamine synthetase (GS) or glutamate dehydrogenase (GDH) were found. We conclude that the accumulation of ammonium under high salt stress was not due to inhibition of the assimilatory activities of GS or GDH. Ammonia accumulation under high salinity may result from amino acid and protein catabolism activated by reactive oxygen species (ROS) and/or a lack of carbon skeletons to incorporate ammonium into organic molecules due to a decrease in photosynthetic activity in salt‐stressed plants.
Comparison of the response of ion distribution in the tissues and cells of the succulent plants Aloe vera and Salicornia europaea to saline stress
Authors: Zheng Qingsong , Liu Ling , Liu Zhaopu , Chen Jianmiao , Zhao Gengmao 
Published: November 2009

AbstractThere exists a great variability among plant species regarding their sensitivity and resistance to high salinity in soil, and most often this variability is related with the ability of a particular plant species to regulate ion homeostasis and transport. In this study, we have investigated the effects of NaCl on growth rate, water status, and ion distribution in different cells and tissues of two succulent plants, Aloe vera and Salicornia europaea. Our results showed that the growth of A. vera seedlings was significantly decreased in response to salinity. However, the growth of S. europaea seedlings was greatly stimulated by high concentrations of NaCl. Under saline conditions, S. europaea seedlings maintained K+ and Ca2+ uptake in roots and showed a higher root‐to‐shoot flux of Na+ and Cl– as compared to A. vera. Despite great accumulation of Na+ and Cl– in photosynthetically active shoot cells in S. europaea, its growth was enhanced, indicating S. europaea is capable of compartmentalizing salt ions in the vacuoles of shoot cells. Aloe vera seedlings, however, showed a low transport rate of Na+ and Cl– to leaves and suppressed uptake of K+ and Ca2+ in roots during NaCl treatment. Our results also implicate that A. vera may be able to accumulate Na+ and Cl– in the metabolically inactive aqueous cells in leaves and, as a result, the plant can survive and can maintain growth under saline conditions.
Superior semicircular canal dehiscence associated with external, middle, and inner ear abnormalities
Authors: Wang Jenny R. , Parnes Lorne S. 
Published: November 2009

AbstractWe report a case of bilateral superior semicircular canal dehiscence (SSCD) in a 38‐year‐old man who presented with congenital hearing loss without vestibular symptoms. This case is unusual due to the association of SSCD with multiple congenital anomalies of the external, middle, and inner ears, but without any other craniofacial or systemic developmental anomalies. Findings of multiple malformations of temporal bone structures in this case lend support to the theory that SSCD may have an underlying developmental or congenital etiology. Laryngoscope, 2010
Severe obstructive sleep apnea: Sleepy versus nonsleepy patients
Authors: Oksenberg Arie , Arons Elena , Nasser Khitam , Shneor Ophir , Radwan Henryk , Silverberg Donald S. 
Published: November 2009

AbstractObjectives/Hypothesis:To compare demographic and polysomnographic data of sleepy versus nonsleepy severe obstructive sleep apnea (OSA) patients according to the Epworth Sleepiness Scale (ESS).Study Design:Retrospective cohort.Methods:Six hundred forty‐four consecutive severe (apnea‐hypopnea index [AHI] ≥ 30) adult OSA patients who underwent a polysomnographic evaluation in our sleep disorders unit. ESS data were available in 569 (88.3%). Three hundred twenty‐seven (57.5%) patients had ESS > 10.Results:Sleepy severe OSA patients are slightly younger and more obese than nonsleepy patients. These sleepy patients have shorter sleep latency and lower percentage of slow wave sleep. They consistently show a higher AHI, both supine and lateral AHI, have a higher number of short arousals, and a higher arousal index. They also have higher snoring loudness in the supine and both lateral positions and a lower minimal SaO2 in rapid eye movement and non‐rapid eye movement sleep. After adjusting for confounders, a logistic regression model points to apnea index as a significant prognostic factor for excessive daytime sleepiness.Conclusions:Severe OSA sleepy patients have a syndrome that is significantly more severe than nonsleepy patients. Sleepy patients have worse sleep‐related breathing parameters, and their sleep patterns are lighter and more fragmented than nonsleepy patients. Apnea index appears as an important prognostic factor for excessive daytime sleepiness. Laryngoscope, 2010
Large‐scale assessment of soil erosion using a neuro‐fuzzy model combined with GIS: A case study of Hubei Province, China
Authors: Zhu D. , Wang T. W. , Cai C. F. , Li L. , Shi Z. H. 
Published: November 2009

AbstractReliable and cost‐effective soil erosion assessment is an important precondition for soil conservation measures, which remains a major challenge at large scale. Considering that the neuro‐fuzzy model has the special advantage in multi‐index comprehensive assessment and GIS technology is adept at geo‐spatial information processing, through the combination of them, it is possible to provide an effective approach for this difficult problem. Taking Hubei Province as a case study area, five evaluating indicators were selected for the large‐scale assessment, in which the GIS technology was used to construct the classification maps of evaluating indicators and to divide basic assessment units, and the neuro‐fuzzy model was adopted to extract fuzzy rules for individual units assessment from available ground truth data. According to the optimized assessment criteria generated by the neuro‐fuzzy model, the soil erosion state of the entire study area was then assessed. To represent the spatial distribution of soil erosion, a detailed map was produced by statistical mapping, which was represented with six erosion levels (from slight to severe) at a map scale of 1:250 000. The resulting map showed that about 30.1% of the total land area in Hubei was affected by different levels of soil erosion problem. Western high mountains and eastern low mountains suffered from the most serious erosion damage, a strong level of soil erosion was widely observed in these mountains. Large areas of moderate level erosion occurred in the northern hills. In contrast, most of the central plains were characterized as slight level erosion effect. The validation indicated that an overall accuracy of 88% and a κ of 0.89 were achieved, proving that the resulting map was in conformity with actual conditions, which indicates this assessment approach was reasonable and applicable. Copyright © 2009 John Wiley & Sons, Ltd.
Survey evidence on price‐setting patterns of Romanian firms
Authors: Copaciu Mihai , Neagu Florian , Braun‐Erdei Horia 
Published: November 2009

AbstractThis paper presents for Romanian firms the results of the first survey on price‐setting patterns among the New Member States of the EU. Diverging from Inflation Persistence Network (IPN) findings, generally small firms perceive higher competitive pressure and adopt the market price, using a state‐dependent rule, while lower perceived competition is consistent with medium and large firms using mark‐up pricing. Prices are reviewed and changed more often than for EMU firms and are more flexible than wages. Similar to IPN evidence, contracts are the main sources of price stickiness. The survey suggests full price transmission of large unanticipated financial shocks. Copyright © 2009 John Wiley & Sons, Ltd.
Difluorobenzenes revisited: an experimental and theoretical study of spin–spin coupling constants for 1,2‐, 1,3‐, and 1,4‐difluorobenzene
Authors: Alkorta Ibon , Blanco Fernando , Del Bene Janet E. , Elguero José , Hernández‐Folgado Laura , Jimeno María‐Luisa 
Published: November 2009

AbstractThe experimental spin–spin coupling constants (SSCCs) for 1,3‐ and 1,4‐difluorobenzene have been determined anew, and found to be consistent with previously determined values. SSCCs for 1,2‐, 1,3‐, and 1,4‐difluorobenzene have been analyzed by comparing them with the coupling constants computed using the second‐order polarization propagator approximation (SOPPA) and the equation‐of‐motion coupled cluster singles and doubles method (EOM‐CCSD). Eighty experimental values have been analyzed using SOPPA calculations, and a subset of 40 values using both SOPPA and EOM‐CCSD approaches. One‐bond coupling constants 1J(CC) and 1J(CF) are better described by EOM‐CCSD, whereas one‐bond 1J(CH) values are better described by SOPPA. An empirical equation is presented which allows for the prediction of unknown coupling constants from computed SOPPA values. A similar approach may prove useful for predicting coupling constants in larger systems. Copyright © 2009 John Wiley & Sons, Ltd.
Insights of the effects of polyethylene glycol 400 on mammalian and avian nerve terminals
Authors: Oshima Mário , Leite Gildo Bernardo , Rostelato‐Ferreira Sandro , Da Cruz‐Höfling Maria Alice , Rodrigues‐Simioni Léa , Oshima‐Franco Yoko 
Published: November 2009

AbstractPolyethylene glycol (PEG) has been widely used as a solvent among other applications. An ideal solvent is one that does not interfere with an in vitro biological system, unless it is a bioactive agent. Herein, a facilitatory neurotransmission effect was exhibited by PEG (20 μM) in mammalian (67 ± 12.5%,n= 4) and avian (74 ± 6.8%,n= 6) neuromuscular preparations. In curarized preparations, PEG did not reverse the neurotransmission blockade induced by D‐tubocurarine (D‐Tc, 5.8 μM,n= 6) as promoted by neostigmine (12 μM,n= 4). A possible presynaptic action of PEG was ruled out, because quantal acetylcholine (ACh) content was similar to the control Tyrode‐incubated mammalian preparation. PEG showed improved sarcolemmal sensitivity, both under direct (sarcolemma) and indirect stimulation (motor axon), because it was able to release calcium from the sarcoplasmic reticulum, even when 30 μM dantrolene (n= 5) was previously applied. Neurotransmission decreased at a higher PEG concentration (100 μM,n= −6) in the depolarized membrane, but it did not alter normal muscle fiber morphology. In addition, it partially recovered twitch tension amplitude (55 ± 5.7%) after washing the preparations. More than a simple solvent, we suggest that PEG 400 is able to act on the sarcolemmal membrane, probably at the triad level, which is in line with its well‐known ability as drug carrier. Muscle Nerve, 2010
Short‐term training adaptations in maximal motor unit firing rates and afterhyperpolarization duration
Authors: Christie Anita , Kamen Gary 
Published: November 2009

AbstractIn this study we investigated age‐ and training‐related adaptations in maximal motor unit firing rates and the duration of the motoneuron afterhyperpolarization (AHP) in the dorsiflexor muscles of the foot. Subjects included 30 young (21.9 ± 3.1 years) and 30 older (72.9 ± 4.6 years) individuals, who were randomly assigned to a control or training group. Maximal voluntary force (MVC), maximal motor unit firing rate, and motoneuron AHP duration were measured on two occasions. The training group participated in six dorsiflexor exercise training sessions between test and retest. At baseline, young subjects had higher MVC force and maximal motor unit firing rate, and shorter AHP duration, compared with older subjects. Young and older subjects in the trained group demonstrated a respective 17.4% and 19.8% increase in MVC force, a 6.8% and 24.3% increase in maximal MUFR, and a 7.4% and 14.2% decrease in AHP duration. These results indicate that age‐related changes in neuromuscular function are not a necessary consequence of aging. Muscle Nerve, 2010