bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rolandic alpha and beta EEG rhythms' strengths are inversely related to fMRI‐BOLD signal in primary somatosensory and motor cortex
Authors: Ritter Petra , Moosmann Matthias , Villringer Arno 
Published: May 2008

AbstractSimilar to the posterior alpha rhythm, pericentral (Rolandic) EEG rhythms in the alpha and beta frequency range are referred to as “idle rhythms” indicating a “resting state” of the respective system. The precise function of these rhythms is not clear. We used simultaneous EEG‐fMRI during a bimanual motor task to localize brain areas involved in Rolandic alpha and beta EEG rhythms. The identification of these rhythms in the MR environment was achieved by a blind source separation algorithm. Rhythm “strength”, i.e. spectral power determined by wavelet analysis, inversely correlated most strongly with the fMRI‐BOLD signal in the postcentral cortex for the Rolandic alpha (mu) rhythm and in the precentral cortex for the Rolandic beta rhythm. FMRI correlates of Rolandic alpha and beta rhythms were distinct from those associated with the posterior “classical” alpha rhythm, which correlated inversely with the BOLD signal in the occipital cortex. An inverse correlation with the BOLD signal in the respective sensory area seems to be a general feature of “idle rhythms”. Hum Brain Mapp 2009. © 2008 Wiley‐Liss, Inc.
Monofractal and multifractal dynamics of low frequency endogenous brain oscillations in functional MRI
Authors: Wink Alle‐Meije , Bullmore Ed , Barnes Anna , Bernard Frederic , Suckling John 
Published: May 2008

AbstractFractal processes, like trees or coastlines, are defined by self‐similarity or power law scaling controlled by a single exponent, simply related to the fractal dimension or Hurst exponent (H) of the process. Multifractal processes, like turbulence, have more complex behaviours defined by a spectrum of possible local scaling behaviours or singularity exponents (h). Here, we report two experiments that explore the relationships between instrumental and cognitive variables and the monofractal and multifractal parameters of functional magnetic resonance imaging (fMRI) data acquired in a no‐task or resting state. First, we show that the Hurst exponent is greater in grey matter than in white matter regions, and it is maximal in grey matter when data were acquired with an echo time known to optimise BOLD contrast. Second, we show that latency of response in a fame decision/facial encoding task was negatively correlated with the Hurst exponent of resting state data acquired 30 min after task performance. This association was localised to a right inferior frontal cortical region activated by the fame decision task and indicated that people with shorter response latency had more persistent dynamics (higher values of H). Multifractal analysis revealed that faster responding participants had wider singularity spectra of resting fMRI time series in inferior frontal cortex. Endogenous brain oscillations measured by fMRI have monofractal and multifractal properties that can be related to instrumental and cognitive factors in a way, which indicates that these low frequency dynamics are relevant to neurocognitive function. Hum Brain Mapp 2008. © 2008 Wiley‐Liss, Inc.
Generation and detection of the radical cation and the dication derived from 4,9‐diethyl[1,4]dihydrodithiino[5,6‐f]benzotrithiole and its 5‐oxide
Authors: Kimura Takeshi , Ito Shinya , Sasaki Takashi , Ogawa Satoshi , Sato Ryu , Kawai Yasushi 
Published: May 2008

Abstract4,9‐Diethyl[1,4]dihydrodithiino[5,6‐f]benzotrithiole (DTBT) gave a radical cation, DTBT(•+), and a dication, DTBT(2+), on treatment with a single‐electron oxidizing reagent. Both compounds showed an ESR signal, whereas the dication, generated by this procedure, was silent for 1H NMR. Hydrolysis of DTBT(2+) gave DTBT 1‐oxide (DTBT 1‐O) and 2‐oxide (DTBT 2‐O) together with DTBT and a mixture of several dioxides. A singlet‐state dication, DTBT(2+)‐S, which was generated upon treatment of DTBT 5‐oxide (DTBT 5‐O) with concentrated D2SO4, was detected by 1H and 13C NMR. After 20 h, the NMR signals disappeared while the solution was active for ESR. The results suggest that (i) a species generated from DTBT by oxidation with the single‐electron oxidizing reagent is a triplet‐state dication, DTBT(2+)‐T, and (ii) DTBT(2+)‐S, initially generated, gradually isomerizes to DTBT(2+)‐T in the solution, and DTBT(2+)‐T forms a partial spin pair. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:394–401, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20445
A comparative analysis of Medicaid long‐term care policies and their effects on elderly dual enrollees
Authors: Rice J. Bradford , Kasper Judith D. , Pezzin Liliana E. 
Published: May 2008

AbstractIndividuals with dual enrollment in Medicare and Medicaid have become the focus of heightened US federal and state policy interest in recent years. These beneficiaries are among the most vulnerable and costly persons served by either program. This analysis uses a reduced‐form econometric model and a unique survey of community‐resident dual enrollees to take a critical step toward understanding the relationships and combinations of state long‐term care (LTC) policies and their relative effectiveness in achieving their intended effects: increasing access to care, improving activities of daily living/instrumental activities of daily living (ADL/IADL) assistance, and reducing unmet needs. We then simulate the effects of alternative policies to determine the most effective combination.The combination of policies that was most effective in reducing the percentage of individuals receiving low levels of assistance was high spending in the community relative to nursing home and low community LTC spending per recipient; that is, spending more on community care and spreading it across more people. Overall, this analysis confirms that Medicaid LTC policy decisions by states, and the combinations of policies that are implemented, result in important variations in levels of assistance to elderly persons with disabilities. Copyright © 2008 John Wiley & Sons, Ltd.
Fluid flow and heat transfer characteristics in rectangular microchannels
Authors: Jiang Jie , Hao Yingli , Shi Mingheng 
Published: May 2008

AbstractExperiments were conducted to investigate flow and heat transfer characteristics of water in rectangular microchannels. All tests were performed with deionized water. The flow rate, the pressures, and temperatures at the inlet and outlet were measured. The friction factor, heat flux, and Nusselt number were obtained. The friction factor in the microchannel is lower than the conventional value. That is only 20% to 30% of the convectional value. The critical Reynolds number below which the flow remains laminar in the microchannel is also lower than the conventional value. The Nusselt number in the microchannel is quite different from the conventional value. The Nusselt number for the microchannel is lower than the conventional value when the flow rate is small. As the flow rate through the microchannel is increased, the Nusselt number significantly increases and exceeds the value of Nusselt number for the fully developed flow in the conventional channel. The micro‐scale effect was exhibited. The Nusselt number is also affected by the heat flux. The Nusselt number remains the constant value when the flow rate is small. The Nusselt number increases with the increase in the heat flux when the flow rate is large. © 2008 Wiley Periodicals, Inc. Heat Trans Asian Res, 37(4): 197–207, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20206
αvβ3 and αvβ5 integrins control glioma cell response to ionising radiation through ILK and RhoB
Authors: Monferran Sylvie , Skuli Nicolas , Delmas Caroline , Favre Gilles , Bonnet Jacques , Cohen‐Jonathan‐Moyal Elizabeth , Toulas Christine 
Published: May 2008

AbstractIntegrins are extracellular matrix receptors involved in tumour invasion and angiogenesis. Although there is evidence that inhibiting integrins might enhance the efficiency of radiotherapy, little is known about the exact mechanisms involved in the integrin‐dependent modulation of tumor radiosensitivity. The purpose of this study was to investigate the role of αvβ3 and αvβ5 integrins in glioblastoma cell radioresistance and overall to decipher the downstream biological pathways. We first demonstrated that silencing αvβ3 and αvβ5 integrins with specific siRNAs significantly reduced the survival after irradiation of 2 glioblastoma cell lines: U87 and SF763. We then showed that integrin activity and integrin signalling pathways controlled the glioma cell radiosensitivity. This regulation of glioma cell response to ionising radiation was mediated through the integrin‐linked kinase, ILK, and the small GTPase, RhoB, by two mechanisms. The first one, independent of ILK, consists in the regulation of the intracellular level of RhoB by αvβ3 or αvβ5 integrin. The second pathway involved in cell radiosensitivity consists in RhoB activation by ionising radiation through ILK. Furthermore, we demonstrated that the αvβ3/αvβ5 integrins/ILK/RhoB pathway controlled the glioma cells radiosensitivity by regulating radiation‐induced mitotic cell death. This work identifies a new biological pathway controlling glioblastoma cells radioresistance, activated from the membrane through αvβ3 and/or αvβ5 integrins via ILK and RhoB. Our results are clues that downstream effectors of αvβ3 and αvβ5 integrins as ILK and RhoB might also be promising candidate targets for improving the efficiency of radiotherapy and thus the clinical outcome of patients with glioblastoma. © 2008 Wiley‐Liss, Inc.
Insig2 is associated with colon tumorigenesis and inhibits Bax‐mediated apoptosis
Authors: Li Chang Gong , Gruidl Mike , Eschrich Steven , McCarthy Susan , Wang Hong‐Gang , Alexandrow Mark G. , Yeatman Timothy J. 
Published: May 2008

AbstractInsulin‐induced gene 2 (Insig2) was recently identified as a putative positive prognostic biomarker for colon cancer prognosis. Insig2 has been previously reported to be an endoplasmic reticulum (ER) membrane protein, and a negative regulator of cholesterol synthesis. Here we report that Insig2 was validated as a gene with univariate negative prognostic capacity to discriminate human colon cancer survivorship. To investigate the functional roles it plays in tumor development and malignancy, Insig2 was over‐expressed in colon cancer cells resulting in increased cellular proliferation, invasion, anchorage independent growth and inhibition of apoptosis. Over‐expression of Insig2 appeared to suppress chemotherapeutic drug treatment‐induced Bcl2 associated X protein (Bax) expression and activation. Insig2 was also found to localize to the mitochondria/heavy membrane fraction and associate with conformationally changed Bax. Moreover, Insig2 altered the expression of several additional apoptosis genes located in mitochondria, further supporting its new functional role in regulating mitochondrial mediated apoptosis. Our findings show that Insig2 is a novel colon cancer biomarker, and suggest, for the first time, a reasonable connection between Insig2 and Bax‐mediated apoptosis through the mitochondrial pathway. © 2008 Wiley‐Liss, Inc.
An in‐silico study of alphaherpesviruses ICP0 genes: Positive selection or strong mutational GC‐pressure?
Authors: Khrustalev Vladislav Victorovich , Barkovsky Eugene Victorovich 
Published: May 2008

AbstractThe purpose of our work was to analyze the case of the strong mutational GC‐pressure influence on the ratio between nonsynonymous (DN) and synonymous (DS) distances (DN/DS ratio). We have used as the material the genes coding for ICP0 from five completely sequenced genomes of simplexviruses. DN/DS ratio, total GC‐content (G + C), and GC‐content in first, second, and third codon positions (1GC, 2GC, and 3GC, respectively) have been calculated separately for exon 2, nonconserved part of exon 3, and conserved part of exon 3 from ICP0 genes. Results showed that DN is more than DS only in the conserved part of exon 3 of ICP0 genes from cercopithecine herpesvirus 2 and cercopithecine herpesvirus 16. However, the cause of this result (DN/DS = 2.54) is the GC‐pressure acting on the coding districts with 3GC = 99% rather than the biological process called positive selection. Only in these two viruses, because of the strong GC‐pressure, 3GC has reached 99% in the conserved part of ICP0 exon 3, and so nucleotide substitutions that increase the GC‐content practically cannot occur in third codon positions, where most substitutions are synonymous. In this case, GC‐pressure has a substrate for nucleotide substitutions only in first and second codon positions, where most substitutions are nonsynonymous. © 2008 IUBMB IUBMB Life, 60(7): 456–460, 2008
ATP and fructose‐2,6‐bisphosphate regulate skeletal muscle 6‐phosphofructo‐1‐kinase by altering its quaternary structure
Authors: Zancan Patricia , Marinho‐Carvalho Monica M. , Faber‐Barata Joana , Dellias João M.M. , Sola‐Penna Mauro 
Published: May 2008

AbstractRecently, it has been demonstrated that fructose‐2,6‐bisphosphate (F2,6BP) protects skeletal muscle 6‐phosphofructo‐1‐kinase (PFK) from thermal inactivation (50 °C) and against the deleterious effects of guanidinium hydrochloride (GdmCl). On the other hand, ATP, when added at its inhibitory concentrations, that is, >1 mM, enhanced either the thermal‐ or GdmCl‐induced inactivation of PFK. Moreover, we concluded that these phenomena were probably due to the stabilization of PFK tetrameric structure by F2,6BP, and the dissociation of this structure into dimers induced by ATP. Aimed at elucidating the effects of F2,6BP and ATP on PFK at the structural and functional levels, the present work correlates the effects of these metabolites on the equilibrium between PFK dimers and tetramers to the regulation promoted on the enzyme catalytic activity. We show that ATP present a dual effect on PFK structure, favoring the formation of tetramer at stimulatory concentrations (up to 1 mM), and dissociating tetramers into dimers at inhibitory concentrations (>1 mM). Furthermore, F2,6BP counteracted this later ATP effect at either the structural or catalytic levels. Additionally, the effects of both F2,6BP or ATP on the equilibrium between PFK tetramers and dimers and on the enzyme activity presented a striking parallelism. Therefore, we concluded that modulation of PFK activity by ATP and F2,6BP is due to the effects of these ligands on PFK quaternary structure, altering the oligomeric equilibrium between PFK tetramers and dimers. © 2008 IUBMB IUBMB Life, 60(8): 526–533, 2008
Shaping mitochondria: The complex posttranslational regulation of the mitochondrial fission protein DRP1
Authors: Santel Ansgar , Frank Stephan 
Published: May 2008

AbstractMitochondria are essential and dynamic cellular organelles differing in size, subcellular distribution, and internal structure. These aspects of mitochondrial morphology are intimately controlled by a growing number of mitochondrial morphology shaping proteins. The past decade has revealed remarkable and often unexpected new insights into the molecular regulation and physiological impact of mitochondrial morphology maintenance. Obviously, proper mitochondrial dynamics, resulting from a tightly regulated equilibrium between opposing mitochondrial fusion and fission activities, is a prerequisite for normal organelle function. Consequently, a disturbance of these activities results in mitochondrial dysfunction and, thus, can lay the foundation for human disorders. Here we specifically focus on recent advances in our understanding of the regulation, activity, and function of dynamin‐related protein 1, the main factor for controlled mitochondrial fission. © 2008 IUBMB IUBMB Life, 60(7): 448–455, 2008
Work of fracture of a composite resin: Fracture‐toughening mechanisms
Authors: Baudin Carmen , Osorio Raquel , Toledano Manuel , de Aza Salvador 
Published: May 2008

AbstractThe aim of this work was to investigate those mechanical parameters able to describe the fracture behavior of dental composite resins. A commercially available fine‐particle micro‐hybrid resin composite was used. Classical parameters as Young's modulus, strength distribution, and critical stress intensity factor were considered. Strength values were determined using the diametrical compression of discs test and for the critical stress intensity factor both unstable and controlled fracture tests were used. Controlled fracture tests allowed determining the work of fracture. Microstructure was studied by optical and field emission scanning electron microscopy. The obtained properties have been Young's modulus, 17.7 ± 0.6 GPa; Weibull modulus, m = 14 (upper and lower limits for 90% confidence: 17 and 10); characteristic strength 51 MPa (upper and lower limits for 90% confidence: 53 and 49 MPa); critical stress intensity factor in mode I, KIC = 1.3 ± 0.1 and work of fracture, γwof = 8–9 J/m2. Pores and bubbles formed during the packing of the composite were identified as critical defects in the tested specimens. Crack deflection and branching have been identified as toughening mechanisms. Classical mechanical parameters (Young's modulus, hardness…) are not able to efficiently predict the major clinical failure mode of composite resins by fatigue. Work of fracture analysis, which is dependant on microstructural parameters such as particle size and shape, have to be included when testing mechanical properties of dental composite resins in future research studies. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Amidine surface modification of poly(acrylonitrile‐co‐vinyl chloride) reduces platelet adhesion
Authors: Yim Evelyn K. F. , Sefton Michael V. 
Published: May 2008

AbstractThe surface nitrile groups of solvent‐cast polyacrylonitrile‐co‐vinyl chloride (PAN‐VC) films were converted into amidine groups through a two‐step process analogous to Pinner's method of 1877. The amidine groups were hypothesized to reduce platelet adhesion and activation through the inhibition of the classical complement pathway, as was noted for benzamidine and pentamidine in earlier studies. A slightly higher nitrogen content was detected on the amidine‐surface modified (ASM) samples by X‐ray photoelectron spectroscopy relative to the solvent‐treated and unmodified controls. Reaction with pentafluoroaldehyde resulted in increased fluorine and decreased nitrogen contents (relative), consistent with the formation of a Schiff base with the primary nitrogen of the amidine on ASM PAN‐VC surface. The corresponding yield was 17.2% based on nitrile groups and 9.6% based on all repeating units of the base polymer. Despite this low degree of amidine modification, platelet adhesion was ∼40% lower on the amidine‐modified film compared to the solvent‐treated and unmodified controls. The scanning electron micrographs also showed less activation in the adherent platelets. A small reduction in C1s binding was also noted on the amidine‐modified surface. Taken together, these results support the notion that amidine modification may be a useful approach to improve the nonthrombogenicity of a biomaterial. However, much effort is required to improve the degree of surface modification and to provide unequivocal evidence linking amidines to the improved thrombogenicity. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Factorial design optimization and in vivo feasibility of poly(ε‐caprolactone)‐micro‐ and nanofiber‐based small diameter vascular grafts
Authors: Nottelet B. , Pektok E. , Mandracchia D. , Tille J.‐C. , Walpoth B. , Gurny R. , Möller M. 
Published: May 2008

AbstractBecause of the severe increase of mortality by cardiovascular diseases, there has been rising interest among the tissue‐engineering community for small‐sized blood vessel substitutes. Here we present small diameter vascular grafts made of slow degradable poly(ε‐caprolactone) nanofibers obtained by electrospinning. The process was optimized by a factorial design approach that led to reproducible grafts with inner diameters of 2 and 4 mm, respectively. Fiber sizes, graft morphology, and the resulting tensile stress and tensile strain values were studied as a function of various parameters in order to obtain optimal vascular grafts for implantation after γ‐sterilization. The influence of polymer concentration, solvent, needle‐collector distance, applied voltage, flow rate, and spinning time has been studied. Consequently, an optimized vascular graft was implanted as an abdominal aortic substitute in nine rats for a feasibility study. Results are given following up a 12‐week implantation period showing good patency, endothelization, and cell ingrowth. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Cytocompatibility and hemocompatibility of a novel chitosan‐alginate gel system
Authors: Notara M. , Scotchford C. A. , Grant D. M. , Weston N. , Roberts G. A. F. 
Published: May 2008

AbstractTwo chitosan‐alginate gel systems in the form of membranes were produced and evaluated. The first membrane was produced by a novel gel system formed after blending N‐(methylsulfonic acid) chitosan with ammonium alginate (CAG1) and the second was an N‐(methylsulfonic acid) chitosan‐sodium alginate blend cross‐linked with glutaraldehyde and calcium chloride (CAG2). The cytocompatibility and hemocompatibility of the gels were examined by assessing the cell viability of 3T3 Swiss mouse fibroblasts, whole blood hemolysis, and platelet activation. Cell viability was not significantly different by exposure to these gels compared to the controls. Both gel types had minimal effect on hemolysis of whole heparinized rabbit blood after 1‐h exposure. Further platelet activation by the surfaces was also minimal. These results indicate that these novel gels merit further investigation for blood contact applications. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Interstitial pregnancy undetected during earlier first‐trimester screening for fetal aneuploidy at 13 weeks' gestation
Authors: Sherer David M. , Dalloul Mudar , Sokolovski Margarita , Borawski Dorota , Granderson Freda , Abulafia, Ovadia 
Published: May 2008

AbstractFirst‐trimester screening for fetal aneuploidy using nuchal translucency (NT), pregnancy‐associated plasma protein A, free or total β‐hCG, and maternal age constitutes a very effective screening test for fetal Down syndrome. We describe a case in which a patient presented at 14 weeks' gestation with an acute abdomen 1 week after first‐trimester screening (including NT measurement) performed elsewhere, which was negative for trisomies 21 and 18. Sonographic examination revealed an interstitial pregnancy with a singleton fetus with present cardiac activity, which had not been noted 1 week earlier at the time of earlier transabdominal NT measurement. This case indicates that successful acquisition of a NT measurement during first‐trimester screening for fetal aneuploidy does not negate the rare possibility of an unusual ectopic pregnancy. © 2008 Wiley Periodicals, Inc. J Clin Ultrasound, 2009