bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sonography in first trimester bleeding
Authors: Dighe Manjiri , Cuevas Carlos , Moshiri Mariam , Dubinsky Theodore , Dogra Vikram S. 
Published: March 2008

AbstractVaginal bleeding is the most common cause of presentation to the emergency department in the first trimester. Approximately half of patients with first trimester vaginal bleeding will lose the pregnancy. Clinical assessment is difficult, and sonography is necessary to determine if a normal fetus is present and alive and to exclude other causes of bleeding (eg, ectopic or molar pregnancy). Diagnosis of a normal intrauterine pregnancy not only helps the physician in terms of management but also gives psychologic relief to the patient. Improved ultrasound technology and high‐frequency endovaginal transducers have enabled early diagnosis of abnormal and ectopic pregnancies, decreasing maternal morbidity and mortality. The main differential considerations of first trimester bleeding are spontaneous abortion, ectopic pregnancy, or gestational trophoblastic disease. This article reviews the causes of first trimester bleeding and the sonographic findings, including normal features of first trimester pregnancy. © 2008 Wiley Periodicals, Inc. J Clin Ultrasound, 2008.
EU aid policy towards the Pacific ACPs
Authors: Dearden Stephen J. H. 
Published: March 2008

AbstractThis paper reviews the EU's development policy in relation to the Pacific members of the African, Caribbean and Pacific group (ACP). It considers the particular characteristics and challenges faced by these island economies before turning to their trade relations with the EU and the Community's aid programme. It considers both the regional assistance programme and the particular experience of Fiji, the largest economy of the South Pacific. Finally, it attempts to draw some more general conclusions as to the effectiveness of EU aid administration and to identify those issues that remain to be addressed including monitoring, performance criteria, deconcentration and policy coherence. Copyright © 2008 John Wiley & Sons, Ltd.
Application of fractional mass for the identification of peptide–oligonucleotide cross‐links by mass spectrometry
Authors: Pourshahian Soheil , Limbach Patrick A. 
Published: March 2008

AbstractA method has been developed to identify oligonucleotide–peptide heteroconjugates by accurate mass measurements using MS. The fractional mass (the decimal fraction mass value following the monoisotopic nominal mass) for peptides and oligonucleotides is different due to their differing molecular compositions. This property has been used to develop the general conditions necessary to differentiate peptides and oligonucleotides from oligonucleotide–peptide heteroconjugates. Peptides and oligonucleotides generated by the theoretical digestion of various proteins and nucleic acids were plotted as nominal mass versus fractional mass. Such plots reveal that three nucleotides cross‐linked to a peptide produce enough change in the fractional mass to be recognized from non‐cross‐linked peptides at the same nominal mass. Experimentally, a Cytochrome c digest was spiked with an oligonucleotide–peptide heteroconjugate and conditions for analyzing the sample using liquid chromatography (LC)‐MS were optimized. Upon analysis of this mixture, all detected masses were plotted on a fractional mass plot and the heteroconjugate could be readily distinguished from non‐cross‐linked peptides. The method developed here can be incorporated into a general proteomics‐like scheme for identifying protein–nucleic acid cross‐links, and this method is equally applicable to characterizing cross‐links generated from protein–DNA and protein–RNA complexes. Copyright © 2008 John Wiley & Sons, Ltd.
Dehydrogenation of tertiary amines in matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry
Authors: Lou Xianwen , Spiering A. J. H. , de Waal Bas F. M. , van Dongen Joost L. J. , Vekemans Jef A. J. M. , Meijer E. W. 
Published: March 2008

AbstractIn the matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI TOF MS) analysis of various compounds synthesized in our laboratory, strong [M − H]+ ion peaks were often observed for the molecules with tertiary amino groups. In this work, the MALDI TOF MS behavior of two groups of compounds that incorporate tertiary amino moieties was investigated. One group is bisurea dimethylanilines (BUDMAs) prepared for the study of molecular recognition in thermoplastic elastomers, and the other group is the poly(propylene imine) diaminobutane dendrimers. The results clearly demonstrate the appearance of the [M − H]+ ions. In order to understand the possible mechanisms for the generation of these ions, a series of model compounds, ranging from primary to tertiary amines, were investigated. Unlike the tertiary amines, no [M − H]+ ion peaks were recorded for the primary amines, and only barely detectable ones, if any, for some secondary amines. It appears that the tertiary amino groups play an important role in the formation of these ions. In addition to MALDI TOF MS analysis, these samples were also applied to electrospray ionization (ESI) MS where no [M − H]+ ions were observed. The results indicate that the generation of [M − H]+ ion is due to the unique MALDI conditions and is likely to be formed via dehydrogenation of a protonated tertiary amine resulting in an NC double bond. The absence of [M − H]+ ion peaks for the primary and secondary amines is probably because upon their formation these ions could easily transfer one proton to the corresponding amines in the MALDI gas‐phase plume, yielding neutral imines that cannot be detected by MS. Copyright © 2008 John Wiley & Sons, Ltd.
Manganese potentiates nuclear factor‐κB‐dependent expression of nitric oxide synthase 2 in astrocytes by activating soluble guanylate cyclase and extracellular responsive kinase signaling pathways
Authors: Moreno Julie A. , Sullivan Kelly A. , Carbone David L. , Hanneman William H. , Tjalkens Ronald B. 
Published: March 2008

AbstractInflammatory activation of glial cells is associated with neuronal injury in several degenerative movement disorders of the basal ganglia, including manganese neurotoxicity. Manganese (Mn) potentiates the effects of inflammatory cytokines on nuclear factor‐κB (NF‐κB)‐dependent expression of nitric oxide synthase 2 (NOS2) in astrocytes, but the signaling mechanisms underlying this effect have remained elusive. It was postulated in the present studies that direct stimulation of cGMP synthesis and activation of mitogen‐activated protein (MAP) kinase signaling pathways underlies the capacity of Mn to augment NF‐κB‐dependent gene expression in astrocytes. Exposure of primary cortical astrocytes to a low concentration of Mn (10 μM) potentiated expression of NOS2 mRNA and protein along with production of NO in response to interferon‐γ (IFNγ) and tumor necrosis factor‐α (TNFα), which was prevented by overexpression of dominant negative IκBα. Mn also potentiated IFNγ‐ and TNFα‐induced phosphorylation of extracellular response kinase (ERK), p38, and JNK, as well as cytokine‐induced activation of a fluorescent NF‐κB reporter construct in transgenic astrocytes. Activation of ERK preceded that of NF‐κB and was required for maximal activation of NO synthesis. Independently of IFNγ/TNFα, Mn‐stimulated synthesis of cGMP in astrocytes and inhibition of soluble guanylate cyclase (sGC) abolished the potentiating effect of Mn on MAP kinase phosphorylation, NF‐κB activation, and production of NO. These data indicate that near‐physiological concentrations of Mn potentiate cytokine‐induced expression of NOS2 and production of NO in astrocytes via activation of sGC, which promotes ERK‐dependent enhancement of NF‐κB signaling. © 2008 Wiley‐Liss, Inc.
Volatile compounds, quality attributes, mineral composition and pericarp structure of South African litchi export cultivars Mauritius and McLean's Red
Authors: Sivakumar Dharini , Naudé Yvette , Rohwer Egmont , Korsten Lise 
Published: March 2008

AbstractBACKGROUND: The aim of this research was to identify the differences in volatile compounds, mineral composition, quality parameters and pericarp structure (at different fruit developmental stages) between two South African litchi export cultivars, Mauritius and McLean's Red, in order to provide a better understanding of the plant intraspecific variation.RESULTS: Citronellol and geraniol were predominant in the aroma profile of cv. Mauritius and conferred characteristic floral, rose, citrus and fruity aromas. In cv. McLean's Red, germacrene D was predominant in the sesquiterpene fraction. Germacrene D and muurolene are associated with a woody smell. Cv. Mauritius had lower soluble solid content/titratable acidity ratio and higher ascorbic acid content than cv. McLean's Red. Cv. McLean's Red had lower pericarp hue angle and higher anthocyanin concentration, which correlated negatively. Significant differences in fruit mineral content and pattern of cuticle accumulation were noted between the two cultivars. The parallel cuticular lines formed a network with intercellular ridges and heavy wax deposits in cv. McLean's Red. Cv. Mauritius showed higher weight loss at 25 °C, suggesting that the dense wax deposits and cuticle structure in cv. McLean's Red could limit moisture loss.CONCLUSION: This investigation shows evidence for the lack of sweet and rose‐like fragrance in litchi cv. McLean's Red. It is the first study to compare volatile compounds responsible for the differing aromas of two South African litchi cultivars. Litchi cultivar improvement and breeding programmes are focused on expansion of the season and yield. The reported information is useful for selection of cultivars and for cultivar breeding programmes focusing on fruit quality and storage potential. Copyright © 2008 Society of Chemical Industry
A quantitative peptide structure vs. retention relationship study
Authors: Oros Gyula , Cserháti Tibor 
Published: March 2008

AbstractThe quantitative relationship between the TLC retention parameters of 28 short peptides and their physicochemical characteristics was calculated using linear regression analysis. It was established that surface parameters exert a significant impact on the retention of peptides and the ratio of non‐polar surface area/polar surface area exerts the highest influence on the retention. This result may be due to the fact that peptides turn towards the apolar surface of the stationary phase with their non‐polar substructures while the polar molecular parts point into the hydrophilic mobile phase.
Short‐chain fatty acids as marker for the degradation of frying fats and oils
Authors: Brühl Ludger , Matthäus Bertrand 
Published: March 2008

AbstractThe determination of fatty acid composition by gas chromatography as a routine task is established in most laboratories dealing with oils and fats. The scope of this method can be enlarged for a preliminary quality control of used frying fats and oils, which is commonly characterized by the determination of polar compounds and polymerized triacylglycerols. However, for screening purposes the determination of the short‐chain fatty acids C7:0 and C8:0 can give an early indication about the quality of used frying fats and oils.
Economies of scale after deregulation in LTL trucking: a test case for the survivor technique
Authors: Giordano James N. 
Published: March 2008

AbstractEarly critics of motor carrier deregulation believed that the policy was unwise because strong economies of scale would lead to harmful market concentration, particularly in the industry's LTL segment. Using two methodologies, the survivor technique and the trans‐log cost function, this study finds that economies of scale do extend across the entire spectrum of firm sizes in LTL trucking. Long‐run average cost appears to decline mildly and at a diminishing rate with increases in firm size, however, such that any cost advantage for larger firms has been insufficient to eliminate new entry and competition from smaller rivals. As a result, after the first 20 years of deregulation, the corresponding increase in market concentration has also been mild. Moreover, the consistency of results from the two methodologies gives credibility to the survivor technique as an empirical method of identifying economies of scale. Copyright © 2008 John Wiley & Sons, Ltd.
Acrylamide in home‐prepared roasted potatoes
Authors: Skog Kerstin , Viklund Gunilla , Olsson Kerstin , Sjöholm Ingegerd 
Published: March 2008

AbstractPotato is one of the world's most widely grown tuber crop, in which starch is the predominant form of carbohydrates. Potatoes can be prepared in many ways: boiled, fried or roasted. Frying and roasting potatoes at high temperatures result in an appetizing crust, but at the same time acrylamide can form. In this study, the concentrations of the acrylamide precursors, asparagine and sugars, were determined in five different Swedish‐grown potato varieties, together with the acrylamide content after typical home‐cooking procedures; oven‐roasting of potato wedges and pan‐frying of cubes of boiled potatoes. Pan‐frying of boiled potato cubes resulted in higher levels of acrylamide (530–1100 μg/kg) than in the wedges (140–250 μg/kg). Blanching combined with a shorter roasting time was shown to be an efficient way of reducing the acrylamide content in roasted potato wedges, especially in the experiments performed after long‐term storage, where the acrylamide content was reduced from 110–260 to 50–140 μg/kg. No correlation was found between precursor content and acrylamide content, and this finding emphasizes the need for further studies on factors affecting acrylamide formation, for example, the availability of precursors at the surface during cooking.
Maternal use of selective serotonin re‐uptake inhibitors and persistent pulmonary hypertension of the newborn
Authors: Källén Bengt , Olausson Petra Otterblad 
Published: March 2008

AbstractIn order to evaluate the previously published association between maternal use of selective serotonin re‐uptake inhibitors (SSRI) and persistent pulmonary hypertension in the neonate (PPHN), we used data from the Swedish Medical Birth Register for the years 1997–2005. Infants were identified from discharge diagnoses, and maternal exposure to drugs from interviews performed in early pregnancy and from prescriptions from the antenatal care service. Putative confounders were studied: an increased risk for PPHN was indicated for high maternal age, for first parity, for maternal BMI, and possibly for maternal smoking. Adjusting for these variables and year of birth, an association between maternal use of SSRI and PPHN in births after 34 completed weeks was identified with a risk ratio of 2.4, 95%CI 1.2–4.3 when based on women who reported the drug use in early pregnancy. When a subgroup of the women were studied who also had prescriptions for SSRI from the antenatal care later in pregnancy, the risk estimate was 3.6, 95%CI 1.2–8.3. The risk estimates were lower than that described previously in the literature, but both estimates could come from the same about 4–5 times increased risk. The mechanism behind the association between SSRI and PPHN is unclear but an increased risk for respiratory problems after maternal use of SSRI is well known, and PPHN could be a rare part of this association. Copyright © 2008 John Wiley & Sons, Ltd.
National trend of antidepressant consumption and its impact on suicide rate in Hungary
Authors: Viola Réka , Benkő Ria , Nagy Gábor , Soós Gyöngyvér 
Published: March 2008

AbstractPurposeThe aim of this study was to analyse the changes in the amount and structure of Hungarian antidepressant consumption at national and regional level, furthermore to investigate the possible relationship between antidepressant sales and trends in suicide rates using regional data.MethodRetrospective analysis of antidepressant sales data was performed on a 12 years period (1993–2004), applying the ATC/DDD methodology developed by WHO. Linear regression model was set up to investigate the trends in antidepressant utilisation. The association between antidepressant consumption and suicide rates was measured by Pearson correlation.ResultsThe nationwide utilisation of antidepressants revealed more than five‐fold increase in the studied 12 year period. The usage of tricyclic antidepressants (N06AA) decreased to one third of the previous value, while the usage of selective serotonin reuptake inhibitors (N06AB) multiplied by 21. The consumption of ‘other antidepressants’ (N06AX) was found very low (3.66 DDD/1000inhabitants/day in 2004). There was not found any significant correlation between increased antidepressant consumption and decreased suicide rates at regional level by our statistical analysis (r min = −0.160; r max = −0.314).ConclusionFurther investigation is required to identify determinants that have contributed to recent decline in suicide rate in Hungary. Copyright © 2008 John Wiley & Sons, Ltd.
Micelles by self‐assembling peptide‐conjugate amphiphile: synthesis and structural characterization
Authors: Accardo Antonella , Tesauro Diego , Del Pozzo Luigi , Mangiapia Gaetano , Paduano Luigi , Morelli Giancarlo 
Published: March 2008

AbstractThe chemical synthesis by solid‐phase methods of a novel amphiphilic peptide, peptide‐conjugate amphiphile (PCA), containing in the same molecule three different functions: (i) the N,N‐bis[2‐[bis(carboxy‐ethyl)amino]ethyl]‐L‐glutamic acid (DTPAGlu) chelating agent, (ii) the CCK8 bioactive peptide, and (iii) a hydrophobic moiety containing four alkyl chains with 18 carbon atoms each, is reported. In water solution at pH 7.4, PCA self‐assembles in very stable micelles at very low concentration [critical micellar concentration (cmc) values of 5 × 10−7 mol kg−1] as confirmed by fluorescence spectroscopy. The structural characterization, obtained with small‐angle neutron scattering (SANS) measurements, indicates that the aggregates are substantially represented by ellipsoidal micelles with an aggregation number of 39 ± 2 and the two micellar axes of about 52 and 26 Å. Copyright © 2008 European Peptide Society and John Wiley & Sons, Ltd.
Evaluating the error caused by load ignorance through simulation of short circuit in electrical power systems
Authors: Al‐Jufout Saleh A. 
Published: March 2008

AbstractReliability of protection and apparatus selection of the electrical power systems depend on the correct and accurate calculation of short‐circuit currents. The simulation of the electrical power systems is one of the methods that is used for the determination of the short‐circuit currents. In this paper, the model of the electrical power system has been represented by a system of differential equations for current determination. These differential equations have been expressed in Cartesian system of coordinates that decreased the number of the equations by one‐third. This paper compares two approaches of short‐circuit simulation in electrical power systems and evaluates the error in the calculated short‐circuit current during both transient and steady‐state conditions. These approaches are as follows: first, the replacement of the load parameters by zero and second, the introduction of fault simulation switch. A fault has been simulated in a study electrical power system and the factors on which the error depends have been determined. In this paper, the envelope of the short‐circuit current has been considered as a comparative criterion. Copyright © 2008 John Wiley & Sons, Ltd.
A barrier‐free atomic radical‐molecule reaction: N (2D) NO2 (2A1) mechanistic study
Authors: Zuo Ming‐Hui , Liu Hui‐Ling , Huang Xu‐Ri , Zhan Jin‐Hui , Sun Chia‐Chung 
Published: March 2008

AbstractThe reaction of N (2D) radical with NO2 molecule has been studied theoretically using density functional theory and ab initio quantum chemistry method. Singlet electronic state [N2O2] potential energy surfaces (PES) are calculated at the CCSD(T)/aug‐cc‐pVDZ//B3LYP/6‐311+G(d) + ZPE and G3B3 levels of theory. All the involved transition states for generation of (2NO) and (O2 + N2) lie much lower than the reactants. Thus, the novel reaction N + NO2 can proceed effectively even at low temperatures and it is expected to play a role in both combustion and interstellar processes. On the basis of the analysis of the kinetics of all pathways through which the reactions proceed, we expect that the competitive power of reaction pathways may vary with experimental conditions for the title reaction. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Influence of mass resolution on species matching in accurate mass and retention time (AMT) tag proteomics experiments
Authors: Masselon Christophe D. , Kieffer‐Jaquinod Sylvie , Brugière Sabine , Dupierris Véronique , Garin Jérôme 
Published: March 2008

AbstractDiverse mass spectrometric instruments have been used to provide data for accurate mass and retention time (AMT) tag proteomics analyses, including ion trap, quadrupole time‐of‐flight, and Fourier transform mass spectrometry (FTMS). An important attribute of these instruments, beside mass accuracy, is their spectral resolution. In fact, the ability to separate peaks with close m/z values is likely to play a major role in enabling species identification and matching in analyses of very complex proteomics samples. In FTMS, resolution is directly proportional to the detection period and can therefore be easily tuned. We took advantage of this feature to investigate the effect of resolution on species identification and matching in an AMT tag experiment. Using an Arabidopsis thaliana chloroplast protein extract as prototypical ‘real‐life’ sample, we have compared the number of detected features, the optimal mass tolerance for species matching, the number of matched species and the false discovery rate obtained at various resolution settings. It appears that while the total number of matches is not significantly affected by a reduction of resolution in the range investigated, the confidence level of identifications significantly drops as evidenced by the estimated false discovery rate. Copyright © 2008 John Wiley & Sons, Ltd.
In situ derivatization/solid‐phase microextraction coupled with gas chromatography/negative chemical ionization mass spectrometry for the determination of trichloroethylene metabolites in rat blood
Authors: Liu Yongzhen , Muralidhara Srinivasa , Bruckner James V. , Bartlett Michael G. 
Published: March 2008

AbstractAn in situ derivatization solid‐phase microextraction (SPME) method has been developed for the determination of the trichloroethylene (TCE) metabolites, trichloroacetic acid (TCA), dichloroacetic acid (DCA) and trichloroethanol (TCOH), in rat blood. The analytical procedure involves derivatization of TCA and DCA to their ethyl esters with acidic ethanol, headspace sampling using SPME, and gas chromatography/negative chemical ionization mass spectrometry (GC/NCI‐MS) determination. Parameters affecting both derivatization efficiency and the headspace SPME procedure, such as the concentration of sulfuric acid, amount of ethanol, derivatization‐extraction temperature and time, sample preheating time, agitator speed and desorption conditions, were optimized. The method showed good linearity over the range of 1–1000 ng/mL in rat blood for each metabolite with correlation coefficients (R2) higher than 0.99. The intra‐day and inter‐day precision and accuracy were less than 10%. The relative recoveries for all analytes were greater than 84%. Validation results demonstrated that selected ion monitoring of the 35Cl and 37Cl isotopes using NCI resulted in reliable and sensitive quantitation of all three TCE metabolites. This validated method was successfully applied to study the toxicokinetic behavior of TCE metabolites following a 1 mg/kg oral dose of TCE. Copyright © 2008 John Wiley & Sons, Ltd.