bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pharmacological modulation of the bOLD response: A study of acetazolamide and glyceryl trinitrate in humans
Authors: Asghar Mohammad S. , Hansen Adam E. , Pedersen Simon , Larsson Henrik B.W. , Ashina Messoud 
Published: July 2011

AbstractPurpose:To examine the effect of acetazolamide, known to increase cerebral blood flow (CBF) and glyceryl trinitrate (GTN), known to increase cerebral blood volume (CBV) on the blood oxygenation level‐dependent (BOLD) response in humans using 3 T magnetic resonance imaging (MRI), and to evaluate how pharmacological agents may modulate cerebral hemodynamic and thereby possibly the BOLD signal.Materials and Methods:Six subjects were randomly allocated to receive acetazolamide, GTN, or placebo in a double‐blind three‐way crossover controlled study. Before, during, and after drug administration we recorded the BOLD response during visual stimulation with reversing checkerboard.Results:We found that acetazolamide caused significant depression of the BOLD response (P = 0.0066). The maximum decrease occurred at 5 minutes after infusion and was 51.9% (95% confidence interval [CI], 22.03–81.76). GTN did not influence the BOLD response (P = 0.55).Conclusion:The BOLD response is decreased during increased CBF by acetazolamide, suggesting an inverse relationship between global CBF and the BOLD response. GTN does not change the BOLD response. This indicates that GTN exerts an effect on the large vessels only and that CBV changes in the microvascular system are necessary to alter the BOLD response. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.
Recovery of hippocampal network connectivity correlates with cognitive improvement in mild alzheimer's disease patients treated with donepezil assessed by resting‐state fMRI
Authors: Goveas Joseph S. , Xie Chunming , Ward B. Douglas , Wu Zhilin , Li Wenjun , Franczak Malgorzata , Jones Jennifer L. , Antuono Piero G. , Li Shi‐Jiang 
Published: July 2011

AbstractPurpose:To identify the neural correlates of cognitive improvement in mild Alzheimer's disease (AD) subjects following 12 weeks of donepezil treatment.Materials and Methods:Resting‐state functional connectivity magnetic resonance imaging (R‐fMRI) was used to measure the hippocampal functional connectivity (HFC) in 14 mild AD and 18 age‐matched normal (CN) subjects. AD subjects were scanned at baseline and after donepezil treatment. CN subjects were scanned only at baseline as a reference to identify regions correlated or anticorrelated to the hippocampus. Before each scan, participants underwent cognitive, behavioral, and functional assessments.Results:After donepezil treatment, neural correlates of cognitive improvement measured by Mini‐Mental State Examination scores were identified in the left parahippocampus, dorsolateral prefrontal cortex (DLPFC), and inferior frontal gyrus. Improvement in AD Assessment Scale‐cognitive subscale scores correlated with the HFC changes in the left DLPFC and middle frontal gyrus. Stronger recovery in the network connectivity was associated with cognitive improvement.Conclusion:R‐fMRI may provide novel insights into the brain's responses to AD treatment in clinical pharmacological trials, and also may predict clinical response. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.
Automatic abdominal fat assessment in obese mice using a segmental shape model
Authors: Tang Yang , Sharma Priyank , Nelson Marvin D. , Simerly Richard , Moats Rex A. 
Published: July 2011

AbstractPurpose:To develop a computerized image analysis method to assess the quantity and distribution of abdominal fat tissues in an obese (ob/ob) mouse model relevant to 7 T magnetic resonance imaging (MRI).Materials and Methods:A novel segmental shape model is presented that separates visceral adipose tissue (VAT) from subcutaneous adipose tissue (SAT). With shape and distance constraints, it deforms a contour inwards from the skin to the muscle wall and separates the connecting adipose tissues in an ob/ob mouse. The fat tissues are segmented by the adaptive fuzzy C means method to compensate for intensity variation in adipose images. The results were obtained by logical operations applied on the extracted fat images and the separated adipose masks.Results:The method was validated by manual segmentations on 109 axial slice images from 7 ob/ob mice. The average correlation coefficients of measured sizes between the automatic and manual results for total adipose tissue (TAT) is 0.907; SAT is 0.944; VAT is 0. 950. The average Dice coefficient of their positions for TAT is 0.941, SAT is 0.935, and VAT is 0.920.Conclusion:The automated results correlate well with manual segmentations and the method can be used to increase laboratory automation. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.
Characterization of β2‐microglobulin conformational intermediates associated to different fibrillation conditions
Authors: Santambrogio Carlo , Ricagno Stefano , Sobott Frank , Colombo Matteo , Bolognesi Martino , Grandori Rita 
Published: July 2011

Abstractβ2‐Microglobulin (β2m) is the light chain of the class‐I major histocompatibility complex, being also the causing agent of dialysis‐related amyloidosis, which results from its accumulation as amyloid material in the skeletal joints. This study describes conformational properties of β2m under two distinct, in vitro amyloidogenic conditions: neutral pH in the presence of 20% 2,2,2‐trifluoroethanol (TFE) and acidic pH in the absence of TFE. Species distribution analysis by electrospray ionization–mass spectrometry (ESI‐MS) is combined with information obtained by ion mobility–mass spectrometry (IM‐MS), fluorescence and circular dichroism (CD) spectroscopy. It is shown that β2m populates quite different conformational ensembles under the two conditions, but both ensembles display a minor fraction of the population in a partially folded state. In spite of similar compactness, these two partially folded forms display different conformations: helical secondary structure is predominant in the species at pH 7.4, 20% TFE, while the low‐pH form is mainly random coil. As temperature is increased, the TFE intermediate looses helical structure becoming more similar to the low‐pH intermediate. The existence of different conformational ensembles may rationalize the different aggregation propensity displayed by β2m under the two fibrillation conditions analyzed here. Copyright © 2011 John Wiley & Sons, Ltd.
Chemical composition and antimicrobial activity of essential oils of Thymus algeriensis, Eucalyptus globulus and Rosmarinus officinalis from Morocco
Authors: Ait‐Ouazzou Abdenour , Lorán Susana , Bakkali Mohammed , Laglaoui Amin , Rota Carmen , Herrera Antonio , Pagán Rafael , Conchello Pilar 
Published: July 2011

AbstractBACKGROUND: The present study reports on the antimicrobial activity and chemical composition of the essential oils (EOs) of Thymus algeriensis, Eucalyptus globulus and Rosmarinus officinalis from Morocco.RESULTS: The composition of these species was analysed by GC‐MS, and 65 components were identified. Eucalyptus globulus EO showed a great similarity with EOs from other regions, with 1,8‐cineole (79.85%) the major component. Also rich in this constituent was Rosmarinus officinalis (43.99%). However, the chemical profile of Thymus algeriensis was rather different, and for the first time such a high content of borneol (23.48%) has been described in this EO. The antimicrobial activity of these species has also been studied against seven pathogenic and spoiling bacteria of significant importance. According to the results, Thymus algeriensis showed the best bacteriostatic and bactericidal effect, followed by Eucalyptus globulus and Rosmarinus officinalis.CONCLUSIONS: As far as we know this is the first time that minimum inhibitory and bactericidal concentration values have been reported for Eucalyptus globulus EO. Our data support the possible use of this EO as well as Thymus algeriensis EO, as potential natural agents in preservatives for food and pharmaceutical products. Copyright © 2011 Society of Chemical Industry
Functional and bioinformatic characterisation of sequence variants of Fad3 gene from flax
Authors: Khadake Rupali , Khonde Vijaykumar , Mhaske Vaishali , Ranjekar Prabhakar , Harsulkar Abhay 
Published: July 2011

AbstractBACKGROUND: Desaturases are enzymes that drive the multi‐step fatty acid biosynthetic pathway. As evident from directed mutagenesis, single base changes in their polypeptide can potentially alter their structure and may result in altered substrate specificity, regioselectivity and even loss of function. The authors have previously isolated several sequence variants of Δ15 desaturase from flax while attempting to clone that gene. The aim of the present study was to analyse these gene variants for their functionality and to predict the tertiary structure of the protein in order to correlate the functional differences with the protein structure.RESULTS: The variants differed in the rate at which they could convert linoleic acid to α‐linolenic acid. The highest conversion rate was 7.03%, while the lowest was 2.39%. The overall shape of the predicted 3D model of the protein is a compact cylinder containing α‐helices and β‐sheets. The Ramchandran plot of this model revealed that 98.5% of the residues are located in allowed region, which denotes a stable structure.CONCLUSION: Although the structures of the variants are apparently similar, subtle changes account for variation in their activity. Besides, these substitutions may alter their cross‐talk with other proteins and thus differentially influence their specificity, localisation and stability, which in turn may explain the diversity in their function. Copyright © 2011 Society of Chemical Industry
Validation of seventh edition AJCC gastric cancer staging modifications
Authors: Kim Dae Hoon , Oh Cheong Ah , Oh Seung Jong , Choi Min Gew , Noh Jae Hyung , Sohn Tae Sung , Bae Jae Moon , Kim Sung 
Published: July 2011

AbstractBackground and ObjectivesThe seventh edition of the AJCC has more detailed staging categories for gastric cancer than does the sixth edition. The aim of our study was to compare the prognostic accuracies of the sixth and seventh AJCC editions for gastric cancer patients.MethodsWe analyzed survival rates by category using the sixth and seventh editions of the AJCC in 10,060 patients with gastric cancer who had undergone gastrectomy between 1994 and 2007 at Samsung Medical Center.ResultsSignificant differences in prognosis were seen when comparing the new stages of the seventh edition of the AJCC that are subgroups of stages IB, II, IIIA, and IV in the sixth edition. In particular, stage IV of the AJCC sixth edition is divided into stages IIB, IIIA, IIIB, IIIC and IV in the seventh edition, and the 5‐year survival rates of these respective stages were 80.2%, 45.3%, 23.5%, 17.2%, and 10.1% (P < 0.001).ConclusionsEach category of the AJCC sixth edition has been divided into multiple stages in the AJCC seventh edition, each with a different prognosis. The newly divided subgroups from AJCC sixth edition stage IV showed more accurate outcome classification based on AJCC seventh edition staging stratification. J. Surg. Oncol. 2012; 105:26–30. © 2011 Wiley Periodicals, Inc.
A simulation‐optimization model to control seawater intrusion in coastal aquifers using abstraction/recharge wells
Authors: Javadi A. A. , Abd‐Elhamid H. F. , Farmani R. 
Published: July 2011

SUMMARYSeawater intrusion is one of the most serious environmental problems in many coastal regions all over the world. Mixing a small quantity of seawater with groundwater makes it unsuitable for use and can result in abandonment of aquifers. Therefore, seawater intrusion should be prevented or at least controlled to protect groundwater resources. This paper presents development and application of a simulation‐optimization model to control seawater intrusion in coastal aquifers using different management scenarios; abstraction of brackish water, recharge of freshwater, and combination of abstraction and recharge. The model is based on the integration of a genetic algorithm optimisation technique and a coupled transient density‐dependent finite element model. The objectives of the management scenarios include determination of the optimal depth, location and abstraction/recharge rates for the wells to minimize the total costs for construction and operation as well as salt concentrations in the aquifer. The developed model is applied to analyze the control of seawater intrusion in a hypothetical confined coastal aquifer. The efficiencies of the three management scenarios are examined and compared. The results show that combination of abstraction and recharge wells is significantly better than using abstraction wells or recharge wells alone as it gives the least cost and least salt concentration in the aquifer. The results from this study would be useful in designing the system of abstraction/recharge wells to control seawater intrusion in coastal aquifers and can be applied in areas where there is a risk of seawater intrusion. Copyright © 2011 John Wiley & Sons, Ltd.
Incidence of placental mosaicism leading to discrepant results between QF‐PCR and karyotyping in 22,825 chorionic villus samples
Authors: Holgado Elaine , Liddle Stuart , Ballard Terry , Levett Lisa 
Published: July 2011

AbstractObjectiveTo review the frequency and analyse the origin of completely discrepant results observed between QF‐PCR and karyotyping in chorionic villus samples (CVS) as a result of placental mosaicism. Also, to assess QF‐PCR results for biallelic or triallelic patterns and determine their significance.MethodsBetween May 2002 and December 2009, 22 825 CVS were received at TDL Genetics for processing by QF‐PCR and karyotype. The QF‐PCR and karyotype data were compared to determine the incidence of discrepant results.ResultsOf the 22 825 samples received, 22 779 (99.8%) gave concordant results between the PCR and karyotype, and 46 samples (0.2%) gave discordant results. Of these discrepant cases, 5 displayed triallelic peaks and 41 displayed biallelic peaks. All discordant results are due to the presence of placental mosaicism, a known limitation of using this sample type for prenatal diagnosis.ConclusionThis retrospective study of placental mosaicism in CVS is the largest single centre study to date and provides a figure for the occurrence of completely discrepant results between QF–PCR and karyotype due to placental mosaicism. This study also demonstrates that the presence of triallelic peaks at QF–PCR is not sufficient to exclude the presence of placental mosaicism. Copyright © 2011 John Wiley & Sons, Ltd.
Temporal and within practice variability in the health improvement network
Authors: Haynes Kevin , Bilker Warren B. , TenHave Tom R. , Strom Brian L. , Lewis James D. 
Published: July 2011

ABSTRACTBackgroundThe Health Improvement Network (THIN) database is a primary care electronic medical record database in the UK designed for pharmacoepidemiologic research. Matching on practice and calendar year often is used to account for secular trends in time and differences across practices. However, little is known about the consistency within practices across observation years and among practices within a given year, in THIN or other large medical record databases.MethodsWe analyzed mortality rates, cancer incidence rates, prescribing rates, and encounter rates across 415 practices from 2000 to 2007 using a practice‐year as the unit of observation in separate random and fixed effects longitudinal Poisson regression models. Adjusted models accounted for aggregate practice‐level characteristics (smoking, obesity, age, and Vision software experience).ResultsIn adjusted models, subsequent calendar years were associated with lower reported mortality rates, increasing cancer reporting rates, increasing prescriptions per patient, and decreasing encounters per patient, with a corresponding linear trend (p < 0.001 for all analyses). For calendar year 2007, the ratio of the 75th percentile to the 25th percentile for crude rate of cancer, mortality, prescriptions, and encounters was 1.63, 1.63, 1.45, and 1.42, respectively. Adjusting for practice characteristics reduced the among‐practice variation by approximately 40%.ConclusionsTHIN data are characterized by secular trends and among‐practice variation, both of which should be considered in the design of pharmacoepidemiology studies. Whether these are trends in data quality or true secular trends could not be definitively differentiated. Copyright © 2011 John Wiley & Sons, Ltd.
Easily accessible oxygen‐containing derivatives of niobium pentachloride as catalytic precursors for ethylene polymerization
Authors: Marchetti Fabio , Pampaloni Guido , Patil Yogesh , Raspolli Galletti Anna Maria , Hayatifar Mohammad 
Published: July 2011

AbstractThe low catalytic activity of NbCl5 as an ethylene polymerization catalyst was significantly increased by the addition of a series of oxygen donors. The novel niobium derivatives NbCl5(OPh2) (1), NbCl5(OEt2) (3), NbCl5(OCPh2) (5), NbCl5(OCHPh) (6), NbCl5(OCHMe) (7) and [NbCl4(dppe)2](NbCl6) (18) (dppe is 1,2‐bis(diphenylphosphino)ethane) and the previously reported derivatives NbCl5(OMePh) (2), NbCl5(thf) (4) (thf is tetrahydrofuran), NbCl5(OCHOMe) (8), NbCl5(OCHNMe2) (9), NbCl5[OC(NMe2)2] (10), NbCl5(NCMe) (11), NbCl4(κ2‐1,2‐OC6H4OMe) (12), NbCl4[κ2‐OC(Me)CH2C(Me2)O] (13), (14), [NbCl4(O2CMe)]2 (15), NbCl3(dme)(µ‐O)NbCl5 (16) (dme is 1,2‐dimethoxyethane), [NbCl4(κ2‐dmm)2](NbCl6) (17) (dmm is dimethylmaleate), TaCl5(OCMe2) (19) and [TaCl4(O2CMe)]2 (20) were tested as catalytic precursors in the ethylene polymerization reaction using AlMe3‐depleted methylaluminoxane as co‐catalyst. Highly linear polyethylene was obtained. Compounds 1, 3, 5, 6 and 8–13 showed catalytic activities in the range 89–116 kgpolymer molNb−1 h−1 bar−1, i.e. comparable with the best performances reached with niobium pre‐catalysts up to now. However, the dinuclear compounds 14–16 and 18 were found to be less active, whereas17 and the tantalum derivatives 19 and 20 did not produce polymer. Relatively high molecular weights were achieved with the mononuclear compounds 1, 2, 8, 9, 10 and 12, the dinuclear 16 and the phosphine ionic 18. Copyright © 2011 Society of Chemical Industry
Effect of methoprene on the progeny production of Tribolium castaneum (Coleoptera: Tenebrionidae)
Authors: Wijayaratne Leanage KW , Fields Paul G , Arthur Frank H 
Published: July 2011

AbstractBACKGROUND: Tribolium castaneum (red flour beetle) is a serious insect pest of stored products around the world. Current control measures for this species have several limitations: loss of registration of insecticides, insecticide resistance and consumer concerns about chemical residues in food. The objective of this study was to determine whether methoprene affects progeny production of T. castaneum. Late‐instar larvae or young adults were exposed to methoprene‐treated wheat, and progeny production was determined. The pairing of male and female adults was performed as untreated × untreated, treated × untreated or treated × treated, to study sex‐based effects.RESULTS: There were three outcomes to late‐instar larvae held on methoprene‐treated wheat kernels (0.001 and 0.0165 ppm): (1) failure to emerge as an adult; (2) emergence as an adult, and almost no offspring produced; (3) emergence as an adult and normal production of offspring. Male larvae were more susceptible to methoprene than female larvae. In contrast, young adults exposed to methoprene (1.67–66.6 ppm) showed no reduction in offspring production.CONCLUSION: Methoprene concentrations will decline with time following its application. However, this research indicates that methoprene can still reduce populations of T. castaneum by reducing their progeny production, even if adults emerge. Copyright © 2011 Society of Chemical Industry
Effect of charge, topology and orientation of the electric field on the interaction of peptides with the α‐hemolysin pore
Authors: Christensen Christopher , Baran Christian , Krasniqi Besnik , Stefureac Radu I. , Nokhrin Sergiy , Lee Jeremy S. 
Published: July 2011

AbstractNanopore analysis is an emerging technique of structural biology which employs nanopores, such as the α‐hemolysin pore, as a biosensor. A voltage applied across a membrane containing a nanopore generates a current, which is partially blocked when a molecule interacts with the pore. The magnitude (I) and the duration (T) of the current blockade provide an event signature for that molecule. Two peptides, CY12(+)T1 and CY12(−)T1 with net charges + 2 and − 2, respectively, were analysed using different applied voltages and all four possible orientations of the electrodes and pore. The four orientations were vestibule downstream (VD), vestibule upstream (VU), stem downstream (SD) and stem upstream (SU) where vestibule and stem refer to the side of the pore on which the peptide was placed and downstream and upstream refer to the application of a positive or negative electrophoretic force, respectively. For CY12(+)T1, the effect of voltage on the event duration was consistent with translocation in the VD and SD configurations, but only intercalation events were observed in the VU and SU configurations. For CY12(−)T1, translocations were only observed in the VD and VU configurations. The results are interpreted in terms of two energy barriers on either side of the lumen of the pore. The difference in height of the barriers determines the preferred direction of exit. Electroosmotic flow and current rectification due to the pore as well as the dipole moment and charge of the peptide also play significant roles. Thus, factors other than simple electrophoresis are important for determining the interaction of small peptides with the pore. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.
The mixed‐spin ferro–ferrimagnetic ternary alloy
Authors: Albayrak Erhan 
Published: July 2011

AbstractThe ${\rm AB}_{p} {\rm C}_{1{-} p} $ type of mixed‐spin ferro–ferrimagnetic ternary‐alloy with the spins SA = 1, SB = 3/2, and SC = 1/2 is investigated on the Bethe lattice on which the A ions are distributed only on the odd shells and B or C ions are distributed randomly on the even shells with the probabilities p and 1 − p, respectively. The phase diagrams are studied for given probabilities p, the ratio of bilinear interaction parameters $R = |J_{{\rm AB}} |/J_{{\rm AC}} $ and the coordination numbers z = 3, 4, 5, and 6 with respect to the reduced temperature. It was found that the critical lines are seen at higher temperatures for higher q, otherwise they are qualitatively similar, therefore, the phase diagrams are only given for q = 6. In addition to the critical temperatures, the model also displays up to four compensation points for appropriate system parameters.
Microscopic theory for insulator to metal transition in cuprates
Authors: Larsson Sven 
Published: July 2011

Abstract“Hubbard U” is equal to the energy of the insulator to metal transition in Mott insulators. Hubbard U is, therefore, also the excitation energy for metal atom to other metal atom transitions and the key concept in photoinduced conductivity spectra of pure and doped cuprates. In this article, the electronic structure of Cu(II) and Cu(III) sites is first discussed. It is shown that Hubbard U depends on the location of the excitation in the CuO2 plane relative to the Cu(III) sites. Far from the Cu(III) sites, the ground‐state wave function continues to be of spin‐coupled type. Near to a Cu(III) site, it changes character and is mixed with charge components. The Hubbard gap thus depends on locality in the CuO2 plane. Close to a Cu(III) site, it tends to zero and induces local conductivity. Far from a Cu(III) site, it is large but converges to zero as the doping levels are raised. In fact, the Hubbard gap has many features in common with the pseudogap. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem 112:1829–1837, 2012