bluuebunny/crossref_metadata_2025_split huggingface dataset:
One‐Dimensional Coordination Polymers of MnII, CuII, and ZnII Supported by Carboxylate‐Appended (2‐Pyridyl)alkylamine Ligands – Structure and Magnetism
Authors: Arora Himanshu , Lloret Francesc , Mukherjee Rabindranath 
Published: June 2009

AbstractFour new complexes [MnII(L1OO)(H2O)][ClO4]·2H2O (1), [ZnII(L1OO)][ClO4]·2H2O (2), [CuII(L3OO)][CF3SO3]·H2O (3), and [ZnII(L3OO)][ClO4] (4) (L1OO– = 3‐[(2‐(pyridine‐2‐yl)ethyl){2‐(pyridine‐2‐yl)methyl}amino]propionate; L3OO– = 3‐[(2‐(pyridine‐2‐yl)ethyl){(dimethylamino)ethyl}amino]propionate) have been synthesized and characterized by elemental analysis, IR, and UV/Vis spectroscopy. Structural analysis revealed that 1, 3, and 4 are one‐dimensional chain‐like coordination polymers. In 1 distorted octahedral MnN3O3 and in 3 square‐pyramidal CuN3O2 coordination is satisfied by three nitrogen atoms and an appended carboxylate oxygen atom of the ligand, and an oxygen atom belonging to the carboxylate group of an adjacent molecule. In 4 trigonal bipyramidal ZnN3O2 coordination environment is provided by two nitrogen atoms and an appended carboxylate oxygen atom of the ligand in the equatorial plane, and the two axial positions are satisfied by a tertiary amine nitrogen and an oxygen atom belonging to the carboxylate group of an adjacent molecule. In 1 the MnII center is coordinated by an additional water molecule. In these complexes each monomeric unit is sequentially connected by syn‐anti carboxylate bridges. Temperature‐dependent magnetic susceptibilities for 1 and 3 are measured, revealing antiferromagnetic interactions through syn‐anti carboxylate bridges between the MII centers. Analysis of the crystal packing diagram reveals that in 1 extensive π–π stacking involving alternate pyridine rings of adjacent 1D chain exists, which eventually lead to the formation of a 2D network structure. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Single‐marker and two‐marker association tests for unphased case‐control genotype data, with a power comparison
Authors: Kim Sulgi , Morris Nathan J. , Won Sungho , Elston Robert C. 
Published: June 2009

AbstractIn case‐control single nucleotide polymorphism (SNP) data, the allele frequency, Hardy Weinberg Disequilibrium, and linkage disequilibrium (LD) contrast tests are three distinct sources of information about genetic association. While all three tests are typically developed in a retrospective context, we show that prospective logistic regression models may be developed that correspond conceptually to the retrospective tests. This approach provides a flexible framework for conducting a systematic series of association analyses using unphased genotype data and any number of covariates. For a single stage study, two single‐marker tests and four two‐marker tests are discussed. The true association models are derived and they allow us to understand why a model with only a linear term will generally fit well for a SNP in weak LD with a causal SNP, whatever the disease model, but not for a SNP in high LD with a non‐additive disease SNP. We investigate the power of the association tests using real LD parameters from chromosome 11 in the HapMap CEU population data. Among the single‐marker tests, the allelic test has on average the most power in the case of an additive disease, but for dominant, recessive, and heterozygote disadvantage diseases, the genotypic test has the most power. Among the four two‐marker tests, the Allelic‐LD contrast test, which incorporates linear terms for two markers and their interaction term, provides the most reliable power overall for the cases studied. Therefore, our result supports incorporating an interaction term as well as linear terms in multi‐marker tests. Genet. Epidemiol. 34:67–77, 2010. © 2009 Wiley‐Liss, Inc.
Neuronal activity rapidly induces transcription of the CREB‐regulated microRNA‐132, in vivo
Authors: Nudelman Aaron S. , DiRocco Derek P. , Lambert Talley J. , Garelick Michael G. , Le Josh , Nathanson Neil M. , Storm Daniel R. 
Published: June 2009

AbstractActivity‐dependent changes in gene‐expression are believed to underlie the molecular representation of memory. In this study, we report that in vivo activation of neurons rapidly induces the CREB‐regulated microRNA miR‐132. To determine if production of miR‐132 is regulated by neuronal activity its expression in mouse brain was monitored by quantitative RT‐PCR (RT‐qPCR). Pilocarpine‐induced seizures led to a robust, rapid, and transient increase in the primary transcript of miR‐132 (pri‐miR‐132) followed by a subsequent rise in mature microRNA (miR‐132). Activation of neurons in the hippocampus, olfactory bulb, and striatum by contextual fear conditioning, odor‐exposure, and cocaine‐injection, respectively, also increased pri‐miR‐132. Induction kinetics of pri‐miR‐132 were monitored and found to parallel those of immediate early genes, peaking at 45 min and returning to basal levels within 2 h of stimulation. Expression levels of primary and mature‐miR‐132 increased significantly between postnatal Days 10 and 24. We conclude that miR‐132 is an activity‐dependent microRNA in vivo, and may contribute to the long‐lasting proteomic changes required for experience‐dependent neuronal plasticity. © 2009 Wiley‐Liss, Inc.
Glass ionomer cement hardness after different materials for surface protection
Authors: Brito Cecilia R. , Velasco Leandro G. , Bonini Gabriela A. V. C. , Imparato José Carlos P. , Raggio Daniela P. 
Published: June 2009

AbstractThe aim of the present study was to evaluate the Knoop hardness of high viscous glass ionomer cement (GIC) Ketac™ Molar Easy Mix (3M ESPE, Saint Paul, USA) submitted to different types of compounds for surface protection. Sixty specimens of GIC were made in PVC molds with 7.5 mm diameter and 2.5 mm thickness. Divided in 6 groups: G1, Control (no protection); G2, Cavitine® (Copal varnish); G3, Magic® bond (Adhesive); G4, Adper™ Single Bond 2 (Single bottle adhesive); G5, Solid Petroleum Jelly; G6, Nail Varnish. The surface protection was applied after initial setting reaction. The specimens were immersed in deionized water, at 37°C, for 24 h. The surfaces were polished in a rotation machine (Aropol 2V). The hardness test was accomplished in a Digital Microhardness tester HVS‐100. In each specimen five indentations were done and repeated after 30 days and 4 months, under the same conditions. The results were submitted to Two‐way ANOVA and Tukey Test. The only material that differed from the control group was the nail varnish (p < 0.001), with the other materials showing no significant difference from the control group. It was concluded that the best material for surface protection of GIC was the nail varnish, but because of possible harmful effects, petrolleum jelly could be a better option. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
The performance of dental pulp stem cells on nanofibrous PCL/gelatin/nHA scaffolds
Authors: Yang Xuechao , Yang Fang , Walboomers X. Frank , Bian Zhuan , Fan Mingwen , Jansen John A. 
Published: June 2009

AbstractThe aim of current study is to investigate the in vitro and in vivo behavior of dental pulp stem cells (DPSCs) seeded on electrospun poly(ε‐caprolactone) (PCL)/gelatin scaffolds with or without the addition of nano‐hydroxyapatite (nHA). For the in vitro evaluation, DNA content, alkaline phosphatase (ALP) activity and osteocalcin (OC) measurement showed that the scaffolds supported DPSC adhesion, proliferation, and odontoblastic differentiation. Moreover, the presence of nHA upregulated ALP activity and promoted OC expression. Real‐time PCR data confirmed these results. SEM micrographs qualitatively confirmed the proliferation and mineralization characteristics of DPSCs on both scaffolds. Subsequently, both scaffolds seeded with DPSCs were subcutaneously implanted into immunocompromised nude mice. Scaffolds with nHA but without cells were implanted as control. Histological evaluation revealed that all implants were surrounded by a thin fibrous tissue capsule without any adverse effects. The cell/scaffold composites showed obvious in vivo hard tissue formation, but there was no sign of tissue ingrowth. Further, the combination of nHA in scaffolds did upregulate the expression of specific odontogenic genes. In conclusion, the incorporation of nHA in nanofibers indeed enhanced DPSCs differentiation towards an odontoblast‐like phenotype in vitro and in vivo. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Polymeric matrix for drug delivery: Honokiol‐loaded PCL‐PEG‐PCL nanoparticles in PEG‐PCL‐PEG thermosensitive hydrogel
Authors: Gou MaLing , Gong ChangYang , Zhang Juan , Wang XiuHong , Wang XianHuo , Gu YingChun , Guo Gang , Chen LiJuan , Luo Feng , Zhao Xia , Wei YuQuan , Qian ZhiYong 
Published: June 2009

AbstractIn this article, we demonstrated a novel injectable polymer matrix: honokiol (HK) loaded poly (ϵ‐caprolactone)‐poly(ethylene glycol)‐poly(ϵ‐caprolactone) (PCL‐PEG‐PCL, PCEC) nanoparticles in thermosensitive poly(ethylene glycol)‐poly(ϵ‐caprolactone)‐poly(ethylene glycol) (PEG‐PCL‐PEG, PECE) hydrogel for the drug local delivery. First, HK, as a model hydrophobic drug, was loaded into PCL‐PEG‐PCL nanoparticles by emulsion solvent evaporation method to overcome its poor water solubility. Then, the HK‐loaded PCEC nanoparticles (HK‐PCEC) were incorporated into thermosensitive PEG‐PCL‐PEG hydrogel, which was sol at low temperature and could gel as a depot for sustained release of drug in situ after topical injection. The HK‐PCEC incorporated PECE hydrogel (HK‐PCEC‐PECE) was biodegradable and could be gradually eliminated from the injection site in about 2 weeks after subcutaneously injected into mice. The in vitro release studies indicated that HK could be released from HK‐PCEC and HK‐PCEC‐PECE in a sustained manner. Such biodegradable smart drug‐delivery system might have great potential application in injectable hydrophobic drug local delivery system. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Fourier transform convolution integrals applied to generalized Born molecular volume
Authors: Schüpbach Thierry , Zoete Vincent , Tsakam‐Sotché Brice , Michielin Olivier 
Published: June 2009

AbstractGeneralized Born methods are currently among the solvation models most commonly used for biological applications. We reformulate the generalized Born molecular volume method initially described by (Lee et al, 2003, J Phys Chem, 116, 10606; Lee et al, 2003, J Comp Chem, 24, 1348) using fast Fourier transform convolution integrals. Changes in the initial method are discussed and analyzed. Finally, the method is extensively checked with snapshots from common molecular modeling applications: binding free energy computations and docking. Biologically relevant test systems are chosen, including 855–36091 atoms. It is clearly demonstrated that, precision‐wise, the proposed method performs as good as the original, and could better benefit from hardware accelerated boards. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2010
Predicting the tautomeric equilibrium of acetylacetone in solution. I. The right answer for the wrong reason?
Authors: Schlund Sebastian , Basílio Janke Eline M. , Weisz Klaus , Engels Bernd 
Published: June 2009

AbstractThis study investigates how the various components (method, basis set, and treatment of solvent effects) of a theoretical approach influence the relative energies between keto and enol forms of acetylacetone, which is an important model system to study the solvent effects on chemical equilibria from experiment and theory. The computations show that the most popular density functional theory (DFT) approaches, such as B3LYP overestimate the stability of the enol form with respect to the keto form by ∼10 kJ mol−1, whereas the very promising SCS‐MP2 approach is underestimating it. MP2 calculations indicate that in particular the basis set size is crucial. The Dunning Huzinaga double ζ basis (D95z(d,p)) used in previous studies overestimates the stability of the keto form considerably as does the popular split‐valence plus polarization (SVP) basis. Bulk properties of the solvent included by continuum approaches strongly stabilize the keto form, but they are not sufficient to reproduce the reversal in stabilities measured by low‐temperature nuclear magnetic resonance experiments in freonic solvents. Enthalpic and entropic effects further stabilize the keto form, however, the reversal is only obtained if also molecular effects are taken into account. Such molecular effects seem to influence only the energy difference between the keto and the enol forms. Trends arising due to variation in the dielectric constant of the solvent result from bulk properties of the solvent, i.e., are already nicely described by continuum approaches. As such this study delivers a deep insight into the abilities of various approaches to describe solvent effects on chemical equilibria. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2010
Influence of differently ionized species on fragmentation pathways and energetics of a potential adenosine receptor antagonist using a triple quadrupole and a multistage LTQ‐Orbitrap™ FTMS instrument
Authors: Zhong Wendy , Irish Patrick A. , Martin Gary E. 
Published: June 2009

Abstract
magnified imageA systematic study was conducted to investigate the influence of differently ionized species on the fragmentation pathways and energetics of a piperazine‐containing adenosine by using different cations or anions. Very different fragmentation mechanisms were observed in protonated‐ versus sodiated‐molecules, which indicated that the proton is mobilized to promote the charge‐direct fragmentation, whereas Na+ cation was fixed at the heterotricyclic ring structure provoking charge‐remote fragment ions. This finding was also supported by the results observed in the fragmentation behaviors in the deprotonated‐molecule. The energetics of these fragment ions were also explored by using the breakdown curves obtained from the triple quadrupole and LTQ‐Orbitrap™ instrument. The data indicated that the lowest energy pathways in the protonated‐molecule [M+H]+ involve breaking a CN bond connecting an ethylene bridge and heterotricyclic ring structure. The lowest energy pathway is the cleavage of a CO bond connecting the methoxy ethyl group and phenolic oxygen to form a distonic radical ion for a sodiated‐molecule [M+Na+]and a deprotonated‐molecule [M‐H]−. The data suggest that by choosing the differently ionized species, one can probe different fragmentation channels that can provide additional structure information for an unknown impurity and possibly degradation product identification. In addition, by comparing the data obtained from triple quadrupole and LTQ‐Orbitrap instruments, one can develop further understanding of the differences in the fragmentation behaviors due to the variations in the collision activation‐dissociation process. From the side‐by‐side comparison with the breakdown curves obtained for both instruments, the difference in fragmentation behaviors caused by the difference in dissociation processes that occur in these two types of instruments can be probed. J. Heterocyclic Chem., (2009).
Persistent decline in longitudinal and radial strain after coronary microembolization detected on velocity encoded phase contrast magnetic resonance imaging
Authors: Dicks Demetrius L. , Carlsson Marcus , Heiberg Einar , Martin Alastair , Saloner David , Arheden Hakan , Saeed Maythem 
Published: June 2009

AbstractPurposeTo use velocity‐encoded phase contrast (PC) MRI in assessing the effect of coronary microembolization on longitudinal and radial myocardial strain.Materials and MethodsA combined X‐ray and MR system (XMR) was used for selective left anterior descending artery catheterization and microinfarct assessment in swine (n = 6). The embolized area at risk was defined on perfusion MRI followed by administration of a 7500 count (size = 100–300 μm) of the embolic agent. Quantification of strain and microinfarction was performed at 1 h and 1 week using PC‐MRI and delayed enhancement (DE) MRI, respectively. At postmortem, sliced hearts were stained to define microinfarction.ResultsBaseline longitudinal and radial strain did not differ between area‐at‐risk and remote myocardium. The embolized territory (area at risk) showed significant decline in longitudinal strain from −11.5 ± 3.2% to 1.8 ± 2.5% at 1 h (P < 0.05) and −3.9 ± 1.1% at 1 week (P < 0.05). Similarly, regional radial strain progressively declined from 23.6 ± 2.5% at baseline to 12.5 ± 3.7% at 1 h (P < 0.05) and 4.8 ± 5.0% at 1 week (P < 0.01). The size of microinfarction was not significantly different between DE‐MRI and histochemical staining.ConclusionPC‐MRI is sensitive in assessing changes in regional longitudinal and radial strain after coronary embolization. Longitudinal and radial strain of the hyperenhanced patchy microinfarction demonstrates persistent decline over the course of 1 week. J. Magn. Reson. Imaging 2009;30:69–76. © 2009 Wiley‐Liss, Inc.
Automated estimation of regional mean transition times and radial velocities from cine magnetic resonance images: Evaluation in normal subjects
Authors: El‐Berbari Racha , Kachenoura Nadjia , Redheuil Alban , Giron Alain , Mousseaux Elie , Herment Alain , Bloch Isabelle , Frouin Frédérique 
Published: June 2009

AbstractPurposeTo assess regional ventricular function via an accurate and automated definition of functional parameters.Materials and MethodsAn automated method is proposed that estimates reliable regional normalized mean transition times (Fmc) and mean radial velocities (Vm) from cine images. This approach combines a quantitative parametric imaging method and an automated detection of the endocardial border, which is robust to the presence of papillary muscles and nonhomogeneities within the left ventricular cavity. Steady‐state free‐precession cine‐magnetic resonance imaging (MRI) of 36 healthy subjects was analyzed.ResultsThe quality of the automated segmentation was assessed on a subgroup of 20 subjects by comparing the results with the manual contours traced by an expert. The comparison of functional parameters estimated consequently using the automated and the manual contours yielded (y = 0.959x + 0.016, R = 0.964) for Fmc and (y = 0.883x + 0.505, R = 0.935) for Vm. On the entire group, Fmc was equal to 0.392 ± 0.069 and Vm to 5.4 ± 2.3 cm/s. Increasing values of the temporal parameter from the apex to the base and larger values in the septal wall than in lateral wall were demonstrated and were in accordance with the physiology.ConclusionThe proposed method ensures an automated and robust assessment of regional wall motion parameters, which could be clinically useful. J. Magn. Reson. Imaging 2009;30:236–242. © 2009 Wiley‐Liss, Inc.
SAR and power implications of different RF shimming strategies in the pelvis for 7T MRI
Authors: van den Bergen Bob , van den Berg Cornelis A.T. , Klomp Dennis W.J. , Lagendijk Jan J.W. 
Published: June 2009

AbstractPurposeTo determine the best radiofrequency (RF) shimming method for 7 T body imaging that provides sufficient B1+ excitation inside the target region while energy deposition (SAR) and power demands are as low as possible and that does not incorporate anatomy specific electric field information inside the patient models, as this information is not available in practice.Materials and MethodsFinite difference time domain (FDTD) simulations were used to evaluate five RF shimming strategies for the pelvis inside a body coil. The results were compared to the theoretical best solution that could be achieved if the electric field inside the patient was known.ResultsMost of the RF shimming strategies were successful. However, between the different strategies a factor of two difference in average SAR reduction, a factor of three difference in local maximum SAR reduction, and a factor of 20 difference in power efficiency was observed. Phase matching was found to be the most promising RF shimming method for the body coil used and patient models.ConclusionRF shimming can reduce the SAR and improve power efficiency in an accurate patient model without knowing the electric field. However, choosing the right method is critical to prevent unexpected behavior in local SAR deposition. J. Magn. Reson. Imaging 2009;30:194–202. © 2009 Wiley‐Liss, Inc.
Characterization of low‐grade gliomas using RGB color maps derived from ADC histograms
Authors: Khayal Inas S. , Nelson Sarah J. 
Published: June 2009

AbstractPurposeTo use normalized apparent diffusion coefficient (nADC) histograms from patients with grade II oligodendroglioma (OD) and astrocytoma (AC) to generate RGB color maps that emphasize the differences between normal‐appearing white matter (NAWM), oligo‐like, and astro‐like regions.Materials and MethodsNAWM and nonenhancing lesion (NEL) ADC values from 19 ODs and 11 ACs were summed to generate oligo‐like (red), NAWM (green), and astro‐like (blue) nADC histograms. These nADC histograms were then used to map nADC values to an RGB matrix.ResultsColor maps of oligodendroglial tumor regions were generally visualized in pink, while color maps of astrocytic tumor regions showed various shades of blue. This technique was also applied to 23 patients with the more mixed subtype, oligoastrocytoma (OA), which showed a mixture of both blue and pink, which in many cases appeared to bleed into each other and were blotchy.ConclusionThis technique allows for the visualization of biologically different regions within the whole tumor mass, which may aid in directing image‐guided biopsies. This can be used to ensure that the biopsy is directed to regions that can more accurately define the dominant tumor characteristics. J. Magn. Reson. Imaging 2009;30:209–213. © 2009 Wiley‐Liss, Inc.
Cine cardiac imaging using black‐blood steady‐state free precession (BB‐SSFP) at 3T
Authors: Basha Tamer A. , Ibrahim El‐Sayed H. , Weiss Robert G. , Osman Nael F. 
Published: June 2009

AbstractPurposeTo propose a new black‐blood (BB) pulse sequence that provides BB cine cardiac images with high blood‐myocardium contrast. The proposed technique is based on the conventional steady‐state free precession (SSFP) sequence.Materials and MethodsNumerical simulations of the Bloch equation were conducted to compare the resulting signal‐to‐noise ratio (SNR) to that of conventional BB imaging, including the effects of changing the imaging flip angle and heart rates. Simulation results were verified using a gel phantom experiment and five normal volunteers were scanned using the proposed technique.ResultsThe new sequence showed higher SNR and contrast‐to‐noise ratio (CNR) (≈100%) compared to the conventional BB imaging. Also, the borders of the left ventricle (LV) and right ventricle (RV) appear more distinguishable than the conventional SSFP. We were also able to cover about 80% of the cardiac cycle with short breath‐hold time (≈10 cardiac cycles) and with reasonable SNR and CNR.ConclusionBased on an SSFP conventional sequence, the new sequence provides BB cines that cover most of the cardiac cycle and with higher SNR and CNR than the conventional BB sequences. J. Magn. Reson. Imaging 2009;30:94–103. © 2009 Wiley‐Liss, Inc.