bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functional connectivity patterns during motor behaviour: The impact of past on present activity
Authors: Serrien Deborah J. 
Published: December 2007

AbstractEveryday behaviour often depends on the performance of multiple movements executed in a particular order. Here, the impact of task history on the neural activation patterns of motor behaviour is examined by evaluating unimanual and bimanual actions that are produced in a serial arrangement, such that switching between tasks is required. Cortical dynamics was assessed by means of EEG coherence in the β frequency band (13–30 Hz). Results showed that although behavioural performance was not affected, switching trials induced increased coherence as compared to control (repeat) trials. Thisreorganization was dependent on task history and was more pronounced for unimanual than for bimanual tasks. Overall, the data illustrate that neural processing of motor behaviour within a serial arrangement integrates past and present activity, and accordingly impacts on neural efficiency. Hum Brain Mapp, 2009. © 2007 Wiley‐Liss, Inc.
Re‐entrant projections modulate visual cortex in affective perception: Evidence from Granger causality analysis
Authors: Keil Andreas , Sabatinelli Dean , Ding Mingzhou , Lang Peter J. , Ihssen Niklas , Heim Sabine 
Published: December 2007

AbstractRe‐entrant modulation of visual cortex has been suggested as a critical process for enhancing perception of emotionally arousing visual stimuli. This study explores how the time information inherent in large‐scale electrocortical measures can be used to examine the functional relationships among the structures involved in emotional perception. Granger causality analysis was conducted on steady‐state visual evoked potentials elicited by emotionally arousing pictures flickering at a rate of 10 Hz. This procedure allows one to examine the direction of neural connections. Participants viewed pictures that varied in emotional content, depicting people in neutral contexts, erotica, or interpersonal attack scenes. Results demonstrated increased coupling between visual and cortical areas when viewing emotionally arousing content. Specifically, intraparietal to inferotemporal and precuneus to calcarine connections were stronger for emotionally arousing picture content. Thus, we provide evidence for re‐entrant signal flow during emotional perception, which originates from higher tiers and enters lower tiers of visual cortex. Hum Brain Mapp, 2009. © 2007 Wiley‐Liss, Inc.
Functional neuroanatomy of CCK‐4‐induced panic attacks in healthy volunteers
Authors: Eser Daniela , Leicht Gregor , Lutz Jürgen , Wenninger Stephan , Kirsch Valerie , Schüle Cornelius , Karch Susanne , Baghai Thomas , Pogarell Oliver , Born Christine , Rupprecht Rainer , Mulert Christoph 
Published: December 2007

AbstractExperimental panic induction with cholecystokinin tetrapeptide (CCK‐4) is considered as a suitable model to investigate the pathophysiology of panic attacks. While only a few studies investigated the brain activation patterns following CCK‐4, no data are available on the putative involvement of the amygdala in the CCK‐4 elicited anxiety response. We studied the functional correlates of CCK‐4‐induced anxiety in healthy volunteers by means of functional magnetic resonance imaging (fMRI) and region of interest (ROI) analysis of the amygdala. Sixteen healthy volunteers underwent challenge with CCK‐4 compared with placebo in a single‐blind design. Functional brain activation patterns were determined for the CCK‐4‐challenge, the placebo response and anticipatory anxiety (AA). CCK‐4‐induced anxiety was accompanied by a strong and robust activation (random effects analysis, P < 0.00001, uncorrected for multiple testing) in the ventral anterior cingulate cortex (ACC), middle and superior frontal gyrus, precuneus, middle and superior temporal gyrus, occipital lobe, sublobar areas, cerebellum, and brainstem. In contrast, random effects group analysis for placebo and AA using the same level of significance generated no significant results. Using a more liberal level of significance, activations could be observed in some brain regions such as the dorsal part of the ACC during AA (random effects analysis, P < 0.005). Overall functional responses did not differ between panickers and nonpanickers. Only 5 of 11 subjects showed strong amygdala activation. However, ROI analysis pointed towards higher scores in fear items in these subjects. In conclusion, while overall brain activation patterns are not related to the subjective anxiety response to CCK‐4, amygdala activation may be involved in the subjective perception of CCK‐4‐induced fear. Hum Brain Mapp, 2009. © 2007 Wiley‐Liss, Inc.
Prediction of microvascular invasion before curative resection of hepatocellular carcinoma
Authors: Kim Beom Kyung , Han Kwang Hyub , Park Young Nyun , Park Mi Suk , Kim Kyung Sik , Choi Jin Sub , Moon Byung Soo , Chon Chae Yoon , Moon Young Myoung , Ahn Sang Hoon 
Published: December 2007

AbstractBackgroundThe accurate staging of hepatocellular carcinoma (HCC) is important in establishing treatment strategies and prognosis. Among tumor factors, microvascular invasion, one of TNM staging components and prognostic factors, is underestimated preoperatively, due to inaccuracy of imaging modalities. We investigated preoperative predictors of microvascular invasion.MethodsWe reviewed 190 consecutive HCC patients given curative resection from 1999 to 2006. All were treatment‐naive and monitored every 3 months after resection. Tumor recurrence, survivals, and clinicopathological factors associated with microvascular invasion were analyzed.ResultsThe 5‐year disease‐free survival (DFS) rate was 39.4%(median follow‐up duration: 35 months). On resection pathology, 38.9% (74/190 patients) had microvascular invasion undetected preoperatively, using liver spiral computed tomography (CT) or angiography. Independent predictors of microvascular invasion were tumor size (P = 0.043), number (P = 0.011), and Edmondson grade (P = 0.001). Patients with Edmondson grade 1 and size <5 cm had no microvascular invasion, while those with grade ≥2 had higher incidences (7/18 patients, 38.8%) even in small tumor (<2 cm). When tumors recurred, presence of microvascular invasion independently increased incidences of multiple tumors, portal vein invasion, and diffuse‐infiltrative patterns significantly.ConclusionsPreoperative predictors of microvascular invasion are tumor size, number, and Edmondson grade, which may be useful for making clinical decisions in both non‐surgical and surgical candidates. J. Surg. Oncol. 2008;97:246–252. © 2007 Wiley‐Liss, Inc.
Kinetic and equilibrium study of the enantioseparation of paroxetine intermediate on amylose and tartaric acid‐based chiral stationary phases
Authors: Bao Zongbi , Su Baogen , Ren Qilong 
Published: December 2007

Abstracttrans‐(–)‐Paroxetine is a selective 5‐hydroxytryptamine (5‐HT) reuptake inhibitor currently used as an antidepressant. trans‐(±)‐3‐Ethoxycarbonyl‐4‐(4′‐fluorophenyl)‐1‐methylpiperidine‐2,6‐dione is an important intermediate of trans‐(–)‐paroxetine. It was separated on amylose and tartaric acid‐based chiral stationary phases by HPLC. The equilibrium constants and overall mass transfer coefficients together with the axial dispersion coefficients were experimentally determined by moment analysis based on the lumped kinetic model of chromatography. In case of Kromasil CHI‐TBB, the equilibrium constants measured were found to be 8.36 and 9.37 for trans‐(+) and trans‐(–) enantiomers, respectively. For Chiralpak AD‐H, the equilibrium constants were 6.68 and 4.13 for trans‐(+) and trans‐(–) enantiomers, respectively. The axial dispersion coefficients of both enantiomers on Kromasil CHI‐TBB column were about one order of magnitude greater than on Chiralpak AD‐H. Fast kinetics of mass transfer in both chiral stationary phases was observed. Their overall mass transfer coefficients on Kromasil CHI‐TBB and Chiralpak AD‐H were 32.12, 33.18, 26.50, 46.85 s–1 for trans‐(+) and trans‐(–) enantiomers, respectively. The parameters obtained were utilized to simulate the elution profiles, and the simulated and experimental results match well, which confirmed that the parameters obtained in this study were valid.
Ischemia‐reperfusion injury. A phenomenon, that also occurs in the bone
Authors: de Groot H. 
Published: December 2007

AbstractIschemia‐reperfusion injury of the bone occurs due to traumatic and non‐traumatic alterations affecting blood supply to the bone. It is likely to occur also upon insertion of an implant. Ischemia‐reperfusion injury of the bone has been studied by interruption of blood supplyin situ, in limb replantation/transplantation models, in revascularized bone grafts and non‐vascularized bone fragments, as well as in isolated cultured cells. All cells of the bone are affected, including osteoblasts, osteocytes, osteoclasts, chondrocytes, and bone marrow cells. Critical ischemia times for induction of bone cell death, either in the ischemic period or following reperfusion, are in the range of 3 to 7 h. These critical ischemia times are significantly increased by decreasing the temperature from 37 °C to 0–4 °C. Anoxia is the most likely trigger of cell injury in the ischemic phase. In the reperfusion phase, reactive oxygen species are decisively involved in the injurious process. In general, however, the available information on the mechanism of ischemia‐reperfusion injury of the bone is relatively sparse. On the other hand, there are clear similarities to the mechanisms of ischemia‐reperfusion injury known from other organs, and there is a clear potential for protection against ischemia‐reperfusion injury of the bone.
Second generation (low modulus) titanium alloys in total hip arthroplasty
Authors: Schuh A. , Bigoney J. , Hönle W. , Zeiler G. , Holzwarth U. , Forst R. 
Published: December 2007

AbstractTitanium alloys ‐ type (α+β) ‐ like Ti6Al7Nb or Ti6Al4V are widely used in cementless total hip arthroplasty due to their lower modulus, biocompatibility and enhanced corrosion resistance in comparison to Stainless Steel or Cobalt‐Chromium implant materials. Several articles report about atrophy of the proximal femur in cases where long stems with a big diameter made of (α+β) Titanium alloys with a relatively high value of the Youngs’ Modulus (110 GPa) in comparison to the Youngs’ Modulus of cortical bone (15–25 GPa) have been implanted using a prosthesis design with distal anchorage technique. Meanwhile several implant manufacturers have developed a new group of biocompatible Beta‐Titanium alloys with a lower Youngs’ Modulus around 70 GPa. This article gives an overview of the current status of available low modulus Titanium alloys including their mechanical characteristics and future developments.
Influence of nickel ions on human multipotent mesenchymal stromal cells (hMSCs)
Authors: Habijan T. , Bremm O. , Esenwein S. A. , Muhr G. , Köller M. 
Published: December 2007

AbstractNickel‐Titanium‐Shape‐Memory‐Alloys (NiTi‐SMA) are of biomedical interest due to an unusual range of pure elastic deformability (superelasticity) and the shape memory effect which allows this material to return to a predictable previously memorized shape after external changes in temperature. HMSCs (human multipotent mesenchymal stromal cells) are currently the most promising cell type for regenerative medicine and tissue engineering, due to the ability to differentiate into several tissues such as bone, tendon, cartilage or muscle. For tissue engineering newly developed porous NiTi‐SMA materials are evaluated preloaded with hMSCs. For biocompatibility testing the high nickel content (50 %at) of NiTi‐SMA plays a critical role. To analyse the influence of Ni‐ions on hMSCs viability and activation, cells were cultured with or without NiCl2 for 24h and 7days. Cells were either seeded in media containing NiCl2 or the NiCl2 was later added to already adherent cells. Cell metabolism, proliferation and viability were analysed by alamarBlueTM assay or fluorescence microscopy. Cytokine (IL‐6, 8, 11) release from hMSCs was determined by ELISA. NiCl2 concentrations below 25 μg/ ml were well tolerated by the cells. A significant decrease in cell proliferation occurred at threshold values of 200 μg/ ml (24 h) and 25 μg/ ml (7 d). There was a significant, dose dependent increase in the release of IL‐8 from hMSCs cultured in the presence of sub toxic NiCl2 concentrations. The present study demonstrates for the first time that high but non‐toxic concentrations of Ni2+ are capable to activate hMSCs. Thus high Ni2+ concentrations apart from allergen‐ or particle‐induced inflammation, may lead to tissue inflammation in the vicinity of a NiTi‐SMA implant in vivo and subsequently to implant failure e.g. due to implant loosening.
Compartmentalized, multiphasic nanocolloids with potential applications in drug delivery and biomedical imaging
Authors: Roh K.‐H. , Yoshida M. , Lahann J. 
Published: December 2007

AbstractNanoparticles are excellent candidates for drug delivery or biomedical imaging, because they often exhibit superb tuneability of critical properties, such as size, surface characteristics, degradation rate, and therefore drug release rates. We have recently developed a route towards fabrication of sub‐micron particles that relies on electrohydrodynamic co‐jetting. In this process, fluid manipulation in an electrical field is used to fabricate large quantities of multi‐compartment particles, where individual compartments can be independently loaded with different drugs or selectively surface‐modified. In this contribution, aspects of multifunctional particles for biomedical applications are reviewed and a specific focus is given to recent progress with compartmentalized, multiphasic nanocolloids in our laboratory.
Torsion sensitivity in NMR of aligned molecules: study on various substituted biphenyls
Authors: Sahakyan Aleksandr B. , Shahkhatuni Aleksan G. , Shahkhatuni Astghik A. , Panosyan Henry A. 
Published: December 2007

AbstractTo estimate the torsion sensitivity of dipolar coupling, biphenylic molecules were chosen as probes due to their relatively simple structure and the surprisingly high ambiguity of the only flexible parameter—the interring torsion angle. Solution structures of 4,4′‐dibromobiphenyl and 4,4′‐diiodobiphenyl are reported for the first time in two liquid crystals I52 and ZLI 1695. The comparison of NMR structures of various para‐substituted biphenyls (BPs), calculated by the additive potential maximum entropy (APME) approach, shows that the small spread of torsion angle values in case of different solvents and para‐substituents is in good agreement with theoretical expectations from hybrid density functional theory (DFT) methods. Furthermore, the real structural changes of interring torsion and the prevalence of solvent effects over para‐halosubstitution can be correctly revealed from these small fluctuations. Copyright © 2007 John Wiley & Sons, Ltd.
13C NMR studies of heterocyclic naphtho‐ and anthraquinones. Deshielding effect on the carbonyl carbon with methyl substitution
Authors: Salas Cristian , Armstrong Veronica , López Claudio , A. Tapia Ricardo 
Published: December 2007

Abstract13C chemical shift assignment of several methyl substituted heterocyclic naphtho‐ and anthraquinones, including dihydronaphthofuranquinones, azaanthraquinones, benzopyrroloquinolinediones and benzothiophenoquinolinediones, are described. A deshielding effect due to a methyl group was observed over the neighbouring carbonyl carbon, in every case studied. 13C assignments were based on 2D experiments. Copyright © 2007 John Wiley & Sons, Ltd.
Qualitative and quantitative differences of cytoskeleton proteins in embryos produced in vitro, in vivo, and by somatic nuclear transfer
Authors: Poehland R. , Tomek W. , Becker F. , Kurth J. , Kanitz W. , Bhojwani S. 
Published: December 2007

AbstractThe cytoskeleton, consisting of complex and dynamic systems of structural filaments, intermediate filaments and microtubules, is not only a structural element but also contributes to many cellular processes such as functional compartments, transportation, mitosis, secretion, formation of cell extensions, and intercellular communication. Suggestions in rat 2‐cell embryos that abnormal distributions of cytoskeletal proteins occurred following the initiations of developmental arrest and our former studies showing reduced intercellular contact zones in cloned bovine embryos prompted us to conduct comparative studies on 8‐cell stage bovine embryos from nuclear transfer (NT), in vitro, and in vivo production. Immunohistochemistry and Laser‐Scanning‐Microscopy facilitated detection of cytoskeleton proteins—α‐tubulin, F‐actin, β‐catenin, and the cell adhesion protein cadherin; image and cluster analysis were subsequently used to study the distribution pattern of the proteins, whereas Western blot was carried out for their qualitative and quantitative analysis. The maximum fluorescence intensity of stained alpha‐tubulin was observed in the cloned and the in vitro embryos. A significant higher intensity of staining for F‐actin was observed in the in vivo and in vitro embryos. In contrast, Western blot revealed no differences of actin, tubulin, and catenin between the three tested groups whereas a lower abundance of cadherin proteins in the cloned embryos was visible. The distribution of actin filaments in cloned embryos was more centric or one‐sided and not peripheral whereas the stained spots of catenin were smaller in comparison to in vivo or in vitro produced embryos. These differences recorded in the distribution patterns may be associated with cell physiological processes related to an influenced actin‐catenin‐cadherin system. In conclusion, reduced intercellular contacts coupled with abnormal distribution of cytoskeletal proteins seem to play an important role in the developmental arrest encountered normally at the 8‐cell stage in bovine cloned embryos. Mol. Reprod. Dev. 75: 1109–1119, 2008. © 2007 Wiley‐Liss, Inc.
A time‐independent approach for computing wave functions of the Schrödinger–Poisson system
Authors: Chien C.‐S. , Jeng B.‐W. , Li Z.‐C. 
Published: December 2007

AbstractWe describe a two‐grid finite element discretization scheme for computing wave functions of the Schrödinger–Poisson (SP) system. To begin with, we compute the first k eigenpairs of the Schrödinger–Poisson eigenvalue (ESP) problem on the coarse grid using a continuation algorithm, where the nonlinear Poisson equation is solved iteratively. We use the k eigenpairs obtained on the coarse grid as initial guesses for computing their counterparts of the ESP on the fine grid. The wave functions of the SP system can be easily obtained using the formula of separation of variables. The proposed algorithm has the following advantages. (i) The initial approximate eigenpairs used in the fine grid can be obtained with low computational cost. (ii) It is unnecessary to discretize the partial derivative of the wave function with respect to the time variable in the SP system. (iii) The major computational difficulties such as closely clustered eigenvalues that occur in the SP system can be effectively computed. Numerical results on the ESP and the SP system are reported. In particular, the rate of convergence of the proposed algorithm is O(h4). Copyright © 2007 John Wiley & Sons, Ltd.
Water uptake and dye sorption studies of chemically crosslinked highly swollen novel ternary acrylamide‐based hydrogels including citraconic acid and sodium acrylate
Authors: Üzüm Ömer Barış , Durukan H. Berna , Kundakci Semiha , Karadağ Erdener 
Published: December 2007

AbstractHighly swollen hydrogels made by the polymerization of acrylamide (AAm) with some anionic monomers such as citraconic acid (CITA) and sodium acrylate (SA) were investigated as a function of composition to find materials with swelling and dye sorption properties. Highly swollen AAm/CITA/SA or AAm/SA/CITA hydrogels were prepared by free radical solution polymerization in aqueous solutions of AAm with CITA and SA as co‐monomers and two multifunctional crosslinkers such as ethylene glycol dimethacrylate (EGDMA) and 1,4‐butanediol dimethacrylate (BDMA). Swelling experiments were performed in water at 25°C, gravimetrically. Chemically crosslinked AAm/CITA/SA or AAm/SA/CITA hydrogels were used in experiments on sorption of water‐soluble monovalent cationic dye such as “Nil blue” (Basic Blue 12; BB 12). Equilibrium percentage swelling values of AAm/CITA/SA or AAm/SA/CITA hydrogels were calculated in the range of 1797–22,098%. Some swelling kinetic parameters were found. Diffusion behavior of water was investigated. Water diffusion into the hydrogels was found to be non‐Fickian in character. For sorption of cationic dye, BB 12 into the hydrogels was studied by batch sorption technique at 25°C. AAm/CITA/SA or AAm/SA/CITA hydrogels in the dye solutions showed coloration, whereas AAm hydrogel did not show sorption of any dye from the solution. The sorption capacity of AAm/CITA/SA or AAm/SA/CITA hydrogels was investigated. At the end of the experiments, 21.70–78.91% BB 12 adsorptions were determined. Copyright © 2007 John Wiley & Sons, Ltd.
Synthesis and characterization of (hydroxypropyl)cellulose/TiO2 nanocomposite films
Authors: Halamus Tomasz , Wojciechowski Piotr , Bobowska Izabela 
Published: December 2007

AbstractA new method of synthesis of TiO2 nanoparticles as well as preparation of the organic–inorganic hybrid nanocomposite films of (hydroxypropyl)cellulose (HPC)/TiO2 is presented. At the first stage, the oxotitanium hydrogel phase was obtained by the mineralization of (tetra‐isopropyl)orthotitanate (TIPT) modified by the methacrylic acid (MAA) in 15 wt% solution of H2O2 at room temperature and subsequent annealing at the temperature of 85°C. The crystallization of the nanoparticles of TiO2 was conducted at the oxotitanium hydrogel phase at temperatures around 120°C in the closed vessel. Nanocomposite hybrid films were prepared by the casting method from a solution of HPC and TiO2 nanoparticles in the water. The films of nanocomposite with 10 µm thickness are transparent to visible light and have a lower glass transition temperature compared with HPC in the bulk. This shift of the glass transition is interpreted in terms of packing density of HPC in the interface of HPC nanocomposite with TiO2. The X‐ray diffraction pattern of the nanocomposite film suggests a lower amount of mesomorphic phase of HPC in the composite compared with HPC in the bulk. Copyright © 2007 John Wiley & Sons, Ltd.