bluuebunny/crossref_metadata_2025_split huggingface dataset:
The timing of cognitive control in partially incongruent categorization
Authors: Chen Antao , Xu Peng , Wang Quanhong , Luo Yuejia , Yuan Jiajin , Yao Dezhong , Li Hong 
Published: September 2007

AbstractWe designed a novel task, partially incongruent categorization (PIC), to examine the timing of cognitive control. In the PIC task, participants categorized the probe stimulus according to a specific concept, and the number of features corresponding to the concept was varied. When there was one feature (c1 condition), the probe would elicit only categorization, but when there was more than one feature (c2 and c3 conditions), the probe would also elicit cognitive control. Here, the high temporal resolution of event‐related potentials (ERPs) was utilized to investigate the temporal patterns of activity during conflict detection and control. Cognitive control elicited a N2 that was much larger in response to c2 and c3 than c1 in stimulus‐locked waveforms, and no difference was evident between c2 and c3. The N2 was followed by a P3 that was much less on c2 and c3 than c1 trials, with no difference between c2 and c3. A dipole source analysis for two difference waves, c2−c1 and c3−c1, further showed that the corresponding dipoles of the N2 and P3 in the cognitive control conditions were in the anterior cingulate cortex (ACC) and prefrontal cortex (PFC), respectively. Taken together, the present findings support that ERP components in response to the PIC task reflect the time course of cognitive control: the N2 responds to conflict information and subsequently activates the P3 to control this conflict. The connection between the ACC and PFC is supported by their sequential activation within trials. Hum Brain Mapp, 2008. © 2007 Wiley‐Liss, Inc.
The neural bases of attentive reading
Authors: Jung Julien , Mainy Nelly , Kahane Philippe , Minotti Lorella , Hoffmann Dominique , Bertrand Olivier , Lachaux Jean‐Philippe 
Published: September 2007

AbstractRecent studies have suggested that attention facilitates the formation of synchronous neural assemblies in the γ range (>40 Hz) to amplify behaviorally relevant signals. Whether this mechanism is general or confined to sensory cortices is still a matter of debate, since there is little evidence of a direct link between attention and increased γ synchronization in high‐level brain regions. We recorded the intracerebral EEG of 10 epileptic patients while manipulating their attention during reading, and compared the neural responses to attended and unattended words. Visual presentation of attended words induced γ band responses in the major brain regions associated with reading and those responses were attenuated for unattended words. The attenuation was not uniform within the reading network but followed a gradient from the posterior visual to the frontal areas. Altogether, these results support the view that the γ band response can be used as a quantitative marker of attention. Hum Brain Mapp 2008. © 2007 Wiley‐Liss, Inc.
An fMRI study on memory discriminability for complex visual scenes
Authors: Blondin François , Lepage Martin 
Published: September 2007

AbstractThe fan effect represents an increase in reaction time for the recognition of an item as a function of the amount of information associated with that item in memory. The present study used fMRI to study the neural correlates of the fan effect for complex visual scenes. We used a test in which landscape pictures were divided vertically into three equal segments. In the high discriminability condition only one segment was presented during encoding, whereas in the low discriminability condition two different segments from the same picture were presented. During a subsequent forced‐choice recognition test, reaction times were significantly faster for the high discriminability condition. Increase in brain activity for the low relative to high discriminability condition was observed in the right prefrontal cortex, several regions of parietal cortex bilaterally, and several late visual processing areas, including the occipito‐temporal regions, precuneus, and cuneus. These results support the hypothesis that a region of the prefrontal cortex is involved in the control of memory interference at retrieval elicited by the amount of related information in memory, and further suggests that this involvement is right‐lateralized for nonverbal material. The high versus low discriminability contrast showed an increase in activity principally in the bilateral medial temporal gyrus, including the enthorinal cortex/hippocampus and in several bilateral prefrontal cortex regions mostly located in BA 10. These activations were associated with a condition, in which the stimuli were more salient in memory and thus could represent the perceptual salience of items in memory. Hum Brain Mapp, 2008. © 2007 Wiley‐Liss, Inc.
Temporal lobe and “default” hemodynamic brain modes discriminate between schizophrenia and bipolar disorder
Authors: Calhoun Vince D. , Maciejewski Paul K. , Pearlson Godfrey D. , Kiehl Kent A. 
Published: September 2007

AbstractSchizophrenia and bipolar disorder are currently diagnosed on the basis of psychiatric symptoms and longitudinal course. The determination of a reliable, biologically‐based diagnostic indicator of these diseases (a biomarker) could provide the groundwork for developing more rigorous tools for differential diagnosis and treatment assignment. Recently, methods have been used to identify distinct sets of brain regions or “spatial modes” exhibiting temporally coherent brain activity. Using functional magnetic resonance imaging (fMRI) data and a multivariate analysis method, independent component analysis, we combined the temporal lobe and the default modes to discriminate subjects with bipolar disorder, chronic schizophrenia, and healthy controls. Temporal lobe and default mode networks were reliably identified in all participants. Classification results on an independent set of individuals revealed an average sensitivity and specificity of 90 and 95%, respectively. The use of coherent brain networks such as the temporal lobe and default mode networks may provide a more reliable measure of disease state than task‐correlated fMRI activity. A combination of two such hemodynamic brain networks shows promise as a biomarker for schizophrenia and bipolar disorder. Hum Brain Mapp 2008. © 2007 Wiley‐Liss, Inc.
Validation of a method for coregistering scalp recording locations with 3D structural MR images
Authors: Whalen Christopher , Maclin Edward L. , Fabiani Monica , Gratton Gabriele 
Published: September 2007

AbstractA common problem in brain imaging is how to most appropriately coregister anatomical and functional data sets into a common space. For surface‐based recordings such as the event related optical signal (EROS), near‐infrared spectroscopy (NIRS), event‐related potentials (ERPs), and magnetoencephalography (MEG), alignment is typically done using either (1) a landmark‐based method involving placement of surface markers that can be detected in both modalities; or (2) surface‐fitting alignment that samples many points on the surface of the head in the functional space and aligns those points to the surface of the anatomical image. Here we compare these two approaches and advocate a combination of the two in order to optimize coregistration of EROS and NIRS data with structural magnetic resonance images (sMRI). Digitized 3D sensor locations obtained with a Polhemus® digitizer can be effectively coregistered with sMRI using fiducial alignment as an initial guess followed by a Marquardt–Levenberg least‐squares rigid‐body transform (df = 6) to match the surfaces. Additional scaling parameters (df = 3) and point‐by‐point surface constraints can also be employed to further improve fitting. These alignment procedures place the lower‐bound residual error at 1.3 ± 0.1 mm (μ ± s) and the upper‐bound target registration error at 4.4 ± 0.6 mm (μ ± s). The dependence of such errors on scalp segmentation, number of registration points, and initial guess is also investigated. By optimizing alignment techniques, anatomical localization of surface recordings can be improved in individual subjects. Hum Brain Mapp, 2008. © 2007 Wiley‐Liss, Inc.
Peginterferon alfa-2b and weight-based or flat-dose ribavirin in chronic hepatitis C patients
Authors: Jacobson Ira M. , Brown Robert S. , Freilich Bradley , Afdhal Nezam , Kwo Paul Y. , Santoro John , Becker Scott , Wakil Adil E. , Pound David , Godofsky Eliot , Strauss Robert , Bernstein David , Flamm Steven , Pauly Mary Pat , Mukhopadhyay Pabak , Griffel Louis H. , Brass Clifford A. 
Published: September 2007

Abstract

This prospective, multicenter, community-based and academic-based, open-label, investigator-initiated, U.S. study evaluated efficacy and safety of pegylated interferon (PEG-IFN) alfa-2b plus a flat or weight-based dose of ribavirin (RBV) in adults with chronic hepatitis C. Patients (n = 5027) were randomly assigned to receive PEG-IFN alfa-2b 1.5 μg/kg/week plus flat-dose (800 mg/day) or weight-based (800-1400 mg/day) RBV for 48 weeks (patients with genotype 1, 4, 5, or 6) and for 24 or 48 weeks (genotype 2/3 patients). Primary end point was sustained virologic response (undetectable [<125 IU/mL] serum hepatitis C virus RNA at 24-week follow-up). Sustained virologic response, but not end-of-treatment, rates were significantly higher with weight-based than with flat-dose RBV (44.2% versus 40.5%;

P

= 0.008). Sustained virologic response rates by intention-to-treat analysis were 34.0% and 28.9%, respectively, in genotype 1 patients (

P

= 0.005) and 31.2% and 26.7%, respectively, in genotype 1 patients with high baseline viral load (

P

= 0.056). In genotype 2/3 patients, rates were not significantly different (61.8% and 59.5%, respectively) regardless of treatment duration. Besides greater hemoglobin reductions with weight-based RBV, safety profiles were similar across RBV dosing groups, including the 1400-mg/day group.

Conclusion:

PEG-IFN alfa-2b plus weight-based RBV is more effective than flat-dose RBV, particularly in genotype 1 patients, providing equivalent efficacy across all weight groups. RBV 1400 mg/day is appropriate for patients 105 to 125 kg. For genotype 2/3 patients, 24 weeks of treatment with flat-dose RBV is adequate; no evidence of additional benefit of extending treatment to 48 weeks was demonstrated. (HEPATOLOGY 2007;46:971–981.)
Classical Benzotriazole‐Mediated α‐Aminoalkylations of Alkynes: Synthesis and Characterization of Alk‐2‐yn‐1‐amines as Amphiphilic Materials
Authors: Idzik Krzysztof R. , Cabaj Joanna , Sołoducho Jadwiga , Abdel‐Fattah Ashraf A. A. 
Published: September 2007

AbstractReactions of readily available and stable benzotriazolemethanamines 1a–l, obtained from aldehydes and secondary amines (Scheme 2), gave the expected alk‐2‐yn‐1‐amines 3a–t (Scheme 3). The amphiphilic character of the synthesized products was responsible for physicochemical measurements. Specific aggregation properties of the obtained compounds make them useful as electroactive materials in the Langmuir–Blodgett technique.
Sesquiterpenoids from the Rhizome of Ligularia virgaurea
Authors: Sun Xiao‐Bai , Xu Yang‐Jun , Qiu Dong‐Feng , Yuan Cheng‐Shan 
Published: September 2007

AbstractTwo novel sesquiterpene dimers, compounds 1 and 2, were isolated from the rhizome of Ligularia virgaurea, together with the six known sesquiterpenoids 3–8. Their structures were established by physico‐chemical and spectroscopic methods, especially by means of 1D‐ and 2D‐NMR as well as HR‐MS analyses. A mechanism based on a classical Diels–Alder cyclization is proposed for the formation of the dimer 1 from the precursors 8 and the quinone form of 6 (Scheme).
A Facile One‐Pot Synthesis of Functionalized 1,5‐Dihydro‐2H‐[1]benzopyrano[2,3‐b]pyridin‐5‐ones
Authors: Esmaeili Abbas Ali , Ghareghani Omid 
Published: September 2007

AbstractThe highly reactive 1 : 1 intermediate generated in the reaction between dialkyl acetylenedicarboxylate (=but‐2‐ynedioic acid dialkyl ester) 4 and triphenylphosphine was trapped by 2‐amino‐4‐oxo‐4H‐1‐benzopyran‐3‐carboxaldehydes 5 to yield highly functionalized dialkyl‐1,5‐dihydro‐5‐oxo‐1‐phenyl‐2H‐[1]benzopyrano[2,3‐b]pyridine‐2,3‐dicarboxylates in high yield.
Synthesis and Transformation of Methyl 2‐(6‐Hydroxy‐2‐phenylpyrimidin‐4‐yl)acetate: Simple Preparation of Pyrimidines with Heterocyclic Substituents
Authors: Bevk David , Grošelj Uroš , Meden Anton , Svete Jurij , Stanovnik Branko 
Published: September 2007

AbstractA simple and efficient synthesis of four new substituted pyrimidines, compounds 9a–d, from the title compound 3 is described. Conversion of 3 to methyl (E)‐3‐(dimethylamino)‐2‐(6‐methoxy‐2‐phenylpyrimidin‐4‐yl)prop‐2‐enoate (4), followed by condensation with various dinucleophiles according to the ‘enaminone methodology’, afforded the target compounds 9 in medium‐to‐good yields.
Novel Bis(bibenzyl) and (Propylphenyl)bibenzyl Derivatives from Dendrobium nobile
Authors: Liu Qun‐Fang , Chen Wen‐Liang , Tang Jian , Zhao Wei‐Min 
Published: September 2007

AbstractTwo novel compounds possessing a bis(bibenzyl) (see 1) and a (propylphenyl)bibenzyl skeleton (see 2) and eight known compounds were isolated from the stems of Dendrobium nobile Lindl. (Orchidaceae). Their structures were identified by spectroscopic analyses.
Phenylpropanoid‐Substituted Catechins and Epicatechins from Smilax china
Authors: Huang Hui‐Lian , Lu Zhi‐Qiang , Chen Guang‐Tong , Zhang Jin‐Qiang , Wang Wei , Yang Min , Guo De‐An 
Published: September 2007

AbstractThe four new phenylpropanoid‐substituted catechins 1, 3, and 4 and 3‐epicatechin (2), together with seven analogues, were isolated from the AcOEt extract of Smilax china L. (catechin=(2R,3S)‐2‐(3,4‐dihydroxyphenyl)‐3,4‐dihydro‐2H‐2‐benzopyran‐3,5,7‐triol). Their structures were determined by means of spectroscopic analyses, including HR‐MS, IR, 1H‐ and 13C‐NMR, and 2D experiments (COSY, HSQC, and HMBC), and comparison with known related compounds.
The First Reaction of Dimethoxycarbene with an Imine Moiety
Authors: Mlostoń Grzegorz , Heimgartner Heinz 
Published: September 2007

AbstractThe nucleophilic dimethoxycarbene (DMC; 2) generated by thermal decomposition of 2,5‐dihydro‐1,3,4‐oxadiazole derivative 1 in boiling toluene reacts smoothly with N‐(9H‐fluoren‐9‐ylidene)‐4‐methylbenzenesulfonamide (7b) to yield carbonimidoate derivative 10. A multi‐step reaction pathway, initiated by the attack of DMC onto the CN bond and followed by the migration of the sulfonyl group (or via a sulfinate anion) is proposed to explain the formation of the final product. In contrast to the formal ketimine 7b, N‐benzylidene‐4‐methylbenzenesulfonamide (7a), a formal aldimine, does not react with DMC under comparable conditions.
Synthesis of New Bis‐imidazole Derivatives
Authors: Jasiński Marcin , Mlostoń Grzegorz , Mucha Paulina , Linden Anthony , Heimgartner Heinz 
Published: September 2007

AbstractThe reaction of aldimines with α‐(hydroxyimino) ketones of type 10 (1,2‐diketone monooximes) was used to prepare 2‐unsubstituted imidazole 3‐oxides 11 bearing an alkanol chain at N(1) (Scheme 2, Table 1). These products were transformed into the corresponding 2H‐imidazol‐2‐ones 13 and 2H‐imidazole‐2‐thiones 14 by treatment with Ac2O and 2,2,4,4‐tetramethylcyclobutane‐1,3‐dithione, respectively (Scheme 3). The three‐component reaction of 10, formaldehyde, and an alkane‐1,ω‐diamine 15 gave the bis[1H‐imidazole 3‐oxides] 16 (Scheme 4, Table 2). With Ac2O, 2,2,4,4‐tetramethylcyclobutane‐1,3‐dithione or Raney‐Ni, the latter reacted to give the corresponding bis[2H‐imidazol‐2‐ones] 19 and 20, bis[2H‐imidazol‐2‐thione] 21, and bis[imidazole] 22, respectively (Schemes 5 and 6). The structures of 11a and 16b were established by X‐ray crystallography.
Novel Sesquiterpenes from Ligularia virgaurea spp. oligocephala
Authors: Liu Xia , Wu Quan‐Xiang , Wei Xiao‐Ning , Shi Yan‐Ping 
Published: September 2007

AbstractTwo novel sesquiterpene dimers, ligularin A (1) and ligulolide D (2), and one new sesquiterpenoid, 1β,10α‐dihydroxy‐6β‐[(2‐methylpropyl)oxy]furanoeremophil‐9‐one (3), as well as two known sesquiterpenoids, 6β‐[(2‐methylpropyl)oxy]‐furanoeremophil‐1(10)‐en‐9‐one (4) and 1‐hydroxy‐3,7‐dimethyl‐2‐(pent‐3‐enyl)benzofuran (5), were isolated from the petroleum‐ether fraction from an alcoholic extract of the whole plant of Ligularia virgaurea spp. oligocephala. Their structures were elucidated by 1D and 2D‐NMR spectroscopy together with HR‐ESI‐MS analysis, and comparison of the spectroscopic data with those reported for structurally related compounds. In addition, the cytotoxicities against human gastric cancer SGC‐7910 cell were measured in vitro, the results demonstrated that these sesquiterpenes have no cytotoxicity against the selected tumor cell (all IC50 values >200 μM).
Chemical Constituents of the Endophytic Fungal Strain Phomopsis sp. NXZ‐05 of Camptotheca acuminata
Authors: Tan Qifang , Yan Xuefen , Lin Xiang , Huang Yaojian , Zheng Zhonghui , Song Siyang , Lu Chunhua , Shen Yuemao 
Published: September 2007

AbstractFrom the endophytic fungal strain Phomopsis sp. NXZ‐05 of Camptotheca acuminata Decne. (Nyssaceae), six new compounds were isolated, including the ten‐membered macrolides 1–4 and their (known) parent compound multiplolide A (7), as well as a new unsaturated fatty acid, (4E)‐6,7,9‐trihydroxydec‐4‐enoic acid (5) and its methyl ester 6. Their structures were elucidated by spectroscopic and mass‐spectrometric analyses, including 1D‐ and 2D‐NMR experiments and HR‐ESI‐MS, and their biological activities were elucidated.
Synthesis and Conformational Analysis of 1′‐ and 3′‐Substituted 2‐Deoxy‐2‐fluoro‐D‐ribofuranosyl Nucleosides
Authors: Sivets Grigorii G. , Kalinichenko Elena N. , Mikhailopulo Igor A. 
Published: September 2007

AbstractConvergent syntheses of the 9‐(3‐X‐2,3‐dideoxy‐2‐fluoro‐β‐D‐ribofuranosyl)adenines 5 (X=N3) and 7 (X=NH2), as well as of their respective α‐anomers 6 and 8, are described, using methyl 2‐azido‐5‐O‐benzoyl‐2,3‐dideoxy‐2‐fluoro‐β‐D‐ribofuranoside (4) as glycosylating agent. Methyl 5‐O‐benzoyl‐2,3‐dideoxy‐2,3‐difluoro‐β‐D‐ribofuranoside (12) was prepared starting from two precursors, and coupled with silylated N6‐benzoyladenine to afford, after deprotection, 2′,3′‐dideoxy‐2′,3′‐difluoroadenosine (13). Condensation of 1‐O‐acetyl‐3,5‐di‐O‐benzoyl‐2‐deoxy‐2‐fluoro‐β‐D‐ribofuranose (14) with silylated N2‐palmitoylguanine gave, after chromatographic separation and deacylation, the N7‐β‐anomer 17 as the main product, along with 2′‐deoxy‐2′‐fluoroguanosine (15) and its N9‐α‐anomer 16 in a ratio of ca. 42 : 24 : 10. An in‐depth conformational analysis of a number of 2,3‐dideoxy‐2‐fluoro‐3‐X‐D‐ribofuranosides (X=F, N3, NH2, H) as well as of purine and pyrimidine 2‐deoxy‐2‐fluoro‐D‐ribofuranosyl nucleosides was performed using the PSEUROT (version 6.3) software in combination with NMR studies.
Bismuth‐Containing SBA‐15 Mesoporous Silica Catalysts for Solvent‐Free Liquid‐Phase Oxidation of Cyclohexane by Molecular Oxygen
Authors: Wang Huan‐Ling , Li Rong , Zheng Yun‐Feng , Chen Hang‐Ning , Jin Jun , Wang Fu‐Shan , Ma Jian‐Tai 
Published: September 2007

AbstractBismuth (Bi)‐containing SBA‐15 mesoporous silica catalysts, Bi/SBA‐15, with different Bi loadings were synthesized by a direct hydrothermal method. The materials were characterized in detail by various techniques. Powder‐X‐ray‐diffraction (PXRD), N2‐adsorption/desorption, and transmission‐electron‐microscopic (TEM) analyses revealed that the well‐ordered hexagonal structure of SBA‐15 is maintained after Bi incorporation. Diffuse‐reflectance UV/VIS, Raman, and X‐ray photoelectron spectroscopy (XPS) showed that the incorporated Bi‐atoms are highly dispersed, most of them entering the internal surface of SBA‐15. The new, very stable catalysts were found to be highly efficient for the oxidation of cyclohexane in a solvent‐free system, molecular oxygen (O2) being used as oxidant.
The neuropsychology of ecstasy (MDMA) use: a quantitative review
Authors: Zakzanis Konstantine K. , Campbell Zachariah , Jovanovski Diana 
Published: September 2007

AbstractA growing number of empirical studies have found varying neuropsychological impairments associated with use of 3,4‐methylenedioxymethamphetamine (MDMA) use. We set out to determine to what extent neuropsychological abilities are impaired in MDMA users. To do so, meta‐analytical methods were used to determine the magnitude of neuropsychological impairment in MDMA users across pre‐specified cognitive domains. We found that cognitive impairment secondary to recreational drug use may result in what might be described as small‐to‐medium effects across all cognitive domains with learning and memory being most impaired. We also found that total lifetime ingestion of MDMA appears to be negatively associated with performance on tasks ranging from attention and concentration to learning and memory. Implications and limitations of these findings are discussed. Copyright © 2007 John Wiley & Sons, Ltd.
An analytical method of analysing the oscillatory pressure head measured at any depth in a well casing
Authors: Chen Chia‐Shyun 
Published: September 2007

AbstractWhen a slug test is conducted in a highly permeable aquifer, a shallow pressure transducer in the well casing produces an oscillatory pressure head that is representative of the water level fluctuation, whereas a deep pressure transducer in the well casing yields an oscillatory pressure head that is different from the water level change. Although the solutions for shallow and deep pressure head are different, it is found that the ratios of the subsequent extremity displacements are in an identical relationship (an extremity can be a maximum or a minimum in the oscillatory pressure head). Based on this relationship, an analytical data analysis method for the determination of the hydraulic conductivity is developed for both shallow and deep pressure transducer data. This analytical method is applied to the pressure head measured at different depths in the well casing of a well partially penetrating an unconfined coarse sand aquifer. Satisfactory results are obtained, validating the applicability of this analytical method for pressure transducer data at any depth in a well casing. Copyright © 2007 John Wiley & Sons, Ltd.
Understanding of hydraulic properties from configurations of stochastically distributed fracture networks
Authors: Wang Mingyu , Kulatilake P. H. S. W. 
Published: September 2007

AbstractA systematic investigation of the effect of configurations of stochastically distributed fracture networks on hydraulic behaviour for fractured rock masses could provide either quantitative or qualitative correlation between the structural configuration of the fracture network and its corresponding hydraulic behaviour, and enhance our understanding of appropriate application of groundwater flow and contaminant transport modelling in fractured rock masses. In this study, the effect of block sizes, intersection angles of fracture sets, standard deviations of fracture orientation, and fracture densities on directional block hydraulic conductivity and representative elementary volume is systematically investigated in two dimensions by implementing a numerical discrete fracture fluid flow model and incorporating stochastically distributed fracture configurations. It is shown from this investigation that the configuration of a stochastically distributed fracture network has a significant quantitative or qualitative effect on the hydraulic behaviour of fractured rock masses. Compared with the deterministic fracture configurations that have been extensively dealt with in a previous study, this investigation is expected to be more practical and adequate, since fracture geometry parameters are inherently stochastically distributed in the field. Moreover, the methodology and approach presented in this study may be generally applied to any fracture system in investigating the hydraulic behaviours from configurations of the fracture system while establishing a ‘bridge’ from the discrete fracture network flow modelling to equivalent continuum modelling in fractured rock masses. Copyright © 2007 John Wiley & Sons, Ltd.