bluuebunny/crossref_metadata_2025_split huggingface dataset:
An efficient synthesis of α‐Amino phosphonates using silica sulfuric acid as a heterogeneous catalyst
Authors: Maghsoodlou Malek Taher , Khorassani Sayyed Mostafa Habibi , Hazeri Nourollah , Rostamizadeh Mohsen , Sajadikhah Seyed Sajad , Shahkarami Zahra , Maleki Nariman 
Published: July 2009

Abstractα‐Amino phosphonates were obtained in a one‐pot, simple, and efficient method from the reaction between aldehyde, aniline, trialkyl phosphite, and silica sulfuric acid as a catalyst in acetonitrile at room temperature. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:316–318, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20543
Axonal sodium channel distribution shapes the depolarized action potential threshold of dentate granule neurons
Authors: Kress Geraldine J. , Dowling Margaret J. , Eisenman Lawrence N. , Mennerick Steven 
Published: July 2009

AbstractIntrinsic excitability is a key feature dictating neuronal response to synaptic input. Here we investigate the recent observation that dentate granule neurons exhibit a more depolarized voltage threshold for action potential initiation than CA3 pyramidal neurons. We find no evidence that tonic GABA currents, leak or voltage‐gated potassium conductances, or the expression of sodium channel isoform differences can explain this depolarized threshold. Axonal initial segment voltage‐gated sodium channels, which are dominated by the NaV1.6 isoform in both cell types, distribute more proximally and exhibit lower overall density in granule neurons than in CA3 neurons. To test possible contributions of sodium channel distributions to voltage threshold and to test whether morphological differences participate, we performed simulations of dentate granule neurons and of CA3 pyramidal neurons. These simulations revealed that cell morphology and sodium channel distribution combine to yield the characteristic granule neuron action potential upswing and voltage threshold. Proximal axon sodium channel distribution strongly contributes to the higher voltage threshold of dentate granule neurons for two reasons. First, action potential initiation closer to the somatodendritic current sink causes the threshold of the initiating axon compartment to rise. Second, the proximity of the action potential initiation site to the recording site causes somatic recordings to more faithfully reflect the depolarized threshold of the axon than in cells like CA3 neurons, with distally initiating action potentials. Our results suggest that the proximal location of axon sodium channels in dentate granule neurons contributes to the intrinsic excitability differences between DG and CA3 neurons and may participate in the low‐pass filtering function of dentate granule neurons. © 2009 Wiley‐Liss, Inc.
Blockade of insulin‐like growth factor‐I has complex effects on structural plasticity in the hippocampus
Authors: Glasper Erica R. , Llorens‐Martin Maria V. , Leuner Benedetta , Gould Elizabeth , Trejo Jose L. 
Published: July 2009

AbstractPhysical exercise enhances adult neurogenesis in the hippocampus. Running induces the uptake of blood insulin‐like growth factor‐I (IGF‐I) into the brain. A causal link between these two phenomena has been reported; running‐induced increases in adult neurogenesis can be blocked by peripheral infusion of anti‐IGF‐I. Running also alters other aspects of hippocampal structure, including dendritic spine density. It remains unclear, however, whether these effects are also mediated through an IGF‐I mechanism. To examine this possibility, we blocked peripheral IGF‐I and examined adult neurogenesis and dendritic spine density in treadmill running mice. Two weeks of running resulted in an increase in cell proliferation in the dentate gyrus (DG) as well as an increase in dendritic spine density on DG granule cells and basal dendrites of CA1 pyramidal neurons, while having no effect on apical or basal dendritic spine density of CA3 pyramidal neurons. IGF‐I blockade reduced cell proliferation in both sedentary and running mice, but by contrast, this treatment had no effect on granule cell or CA3 pyramidal cell dendritic spine density in sedentary or running mice. However, IGF‐I antibody treatment seemed to prevent the running‐induced increase in spine density on basal dendrites of CA1 pyramidal cells. These results suggest that IGF‐I exerts a complex influence over hippocampal structure and that its effects are not restricted to those induced by running. © 2009 Wiley‐Liss, Inc.
Mammalian polyamine metabolism and function
Authors: Pegg Anthony E. 
Published: July 2009

AbstractPolyamines are ubiquitous small basic molecules that play multiple essential roles in mammalian physiology. Their cellular content is highly regulated and there is convincing evidence that altered metabolism is involvement in many disease states. Drugs altering polyamine levels may therefore have a variety of important targets. This review will summarize the current state of understanding of polyamine metabolism and function, the regulation of polyamine content, and heritable pathological conditions that may be derived from altered polyamine metabolism. © 2009 IUBMB IUBMB Life 61(9): 880–894, 2009
Long‐run relations in European electricity prices
Authors: Bosco Bruno , Parisio Lucia , Pelagatti Matteo , Baldi Fabio 
Published: July 2009

AbstractThis paper analyses the interdependencies existing in wholesale electricity prices in six major European countries. The results of a robust multivariate long‐run dynamic analysis reveal the presence of four highly integrated central European markets (France, Germany, the Netherlands and Austria). The trend shared by these four electricity markets appears to be common also to gas prices, but not to oil prices. The existence of a common long‐term dynamics among electricity prices and between electricity prices and gas prices can be explained by the similarity of the market design across Europe and by the same marginal generation technology. Since standard unit root and cointegration tests are not robust to the peculiar characteristics of electricity prices time series, we also develop a battery of robust inference procedures that should assure the reliability of our results. Copyright © 2009 John Wiley & Sons, Ltd.
Forecast encompassing tests and probability forecasts
Authors: Clements Michael P. , Harvey David I. 
Published: July 2009

AbstractWe consider tests of forecast encompassing for probability forecasts, for both quadratic and logarithmic scoring rules. We propose test statistics for the null of forecast encompassing, present the limiting distributions of the test statistics, and investigate the impact of estimating the forecasting models' parameters on these distributions. The small‐sample performance is investigated, in terms of small numbers of forecasts and model estimation sample sizes. We show the usefulness of the tests for the evaluation of recession probability forecasts from logit models with different leading indicators as explanatory variables, and for evaluating survey‐based probability forecasts. Copyright © 2009 John Wiley & Sons, Ltd.
Effects of resveratrol analogs on steroidogenesis and mitochondrial function in rat Leydig cells in vitro
Authors: Svechnikov Konstantin , Spatafora Carmela , Svechnikova Irina , Tringali Corrado , Söder Olle 
Published: July 2009

AbstractResveratrol and its analogs are considered to be a promising drug candidate for treatment of cancer and different age‐associated diseases. In the present study we have investigated the effects of resveratrol and its synthetic analogs on steroidogenesis and mitochondrial function in primary cultures of rat Leydig cells. Our findings indicate that resveratrol and its analogs structure‐dependently attenuated hCG‐activated steroidogenesis in Leydig cells through suppression of the expression of steroidogenic acute regulatory protein and cytochrome P450c17. 3,5‐Diacetyl resveratrol was observed to modulate mitochondrial function in Leydig cells, suppressing polarization of inner mitochondrial membrane, and 3,4,4′‐trimethoxystilbene stimulated the overall activity of intracellular reductases involved in the reduction of WST‐1 to formazan. Thus, the inhibitory actions of resveratrol analogs on steroidogenesis in Leydig cells indicate novel mechanisms of action of these compounds, which may be of potential therapeutic interest, where suppression of androgen action is needed. Copyright © 2009 John Wiley & Sons, Ltd.
Minireview: does in‐vitro testing of oximes help predict their in‐vivo action after paraoxon exposure?
Authors: Lorke D. E. , Petroianu G. A. 
Published: July 2009

AbstractK‐oximes have recently been developed in the search for efficacious broad‐band reactivators of acetylcholinesterase (AChE) inhibited by organophosphorus compounds (OPC). Before clinical use, their toxicity and efficacy need to be assessed, and there is clear demand for simple in vitro tests that can predict in vivo performance. This article summarizes our in vitro data obtained for conventional and experimental oximes in human and rat blood exposed to the OPC paraoxon and correlates them with our in vivo results. The intrinsic AChE inhibitory activity of oximes, as reflected by their in vitro IC50, is strongly correlated with their LD50 (rat): oximes with a high IC50 (K‐27, K‐48, pralidoxime and obidoxime) also show a high LD50 and are thus relatively non‐toxic, whereas oximes K‐105, K‐108 and K‐113 have a low IC50, a low LD50 and are far more toxic. The IC50 is also correlated with the in vivo capacity to protect from paraoxon‐induced mortality: oximes with a higher IC50 reduce the relative risk of death more. In contrast, the protective ability as assessed in vitro by the slope of the IC50 shift (tanα), is not correlated with in vivo protection from paraoxon‐induced mortality: the best in vivo protectors (K‐27 and K‐48) show a much lower tanα value (around 2) than K‐110 and K‐113 (tanα around 10), which hardly reduce the relative risk of death after paraoxon exposure. The partition coefficient logP of the individual oximes is inversely correlated with their IC50 and with their LD50 and is therefore an indicator of toxicity: strongly hydrophilic oximes tend to be less toxic than less hydrophilic ones. These data highlight the good predictive value of in vitro IC50 testing for in vivo toxicity and the limited practical significance of in vitro assessment of protective potency. Copyright © 2009 John Wiley & Sons, Ltd.
Targeted optical injection of gold nanoparticles into single mammalian cells
Authors: McDougall Craig , Stevenson David J. , Brown Christian T. A. , Gunn‐Moore Frank , Dholakia Kishan 
Published: July 2009

AbstractWe present an all optical technique for the targeted delivery of single 100 nm diameter gold nanoparticles into a specified region of the interior of an individual mammalian cell through a combination of optical tweezing and optical injection. The internalisation of the nanoparticle is verified by confocal laser scanning microscopy and confocal laser scanning reflectance microscopy. This represents the first time that nano sized particles have been tweezed and optically injected into mammalian cells using only light, and provides a novel methodology for internalising nanosphere based biosensors within specific intracellular regions of a mammalian cell. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Graph‐theoretical identification of dissociation pathways on free energy landscapes of biomolecular interaction
Authors: Wang Ling , Stumm Boris , Helms Volkhard 
Published: July 2009

AbstractBiomolecular association and dissociation reactions take place on complicated interaction free energy landscapes that are still very hard to characterize computationally. For large enough distances, though, it often suffices to consider the six relative translational and rotational degrees of freedom of the two particles treated as rigid bodies. Here, we computed the six‐dimensional free energy surface of a dimer of water‐soluble alpha‐helices by scanning these six degrees of freedom in about one million grid points. In each point, the relative free energy difference was computed as the sum of the polar and nonpolar solvation free energies of the helix dimer and of the intermolecular coulombic interaction energy. The Dijkstra graph algorithm was then applied to search for the lowest cost dissociation pathways based on a weighted, directed graph, where the vertices represent the grid points, the edges connect the grid points and their neighbors, and the weights are the reaction costs between adjacent pairs of grid points. As an example, the configuration of the bound state was chosen as the source node, and the eight corners of the translational cube were chosen as the destination nodes. With the strong electrostatic interaction of the two helices giving rise to a clearly funnel‐shaped energy landscape, the eight lowest‐energy cost pathways coming from different orientations converge into a well‐defined pathway for association. We believe that the methodology presented here will prove useful for identifying low‐energy association and dissociation pathways in future studies of complicated free energy landscapes for biomolecular interaction. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2010
On the use of symmetry in the ab initio quantum mechanical simulation of nanotubes and related materials
Authors: Noel Yves , D'arco Philippe , Demichelis Raffaella , Zicovich‐Wilson Claudio M. , Dovesi Roberto 
Published: July 2009

AbstractNanotubes can be characterized by a very high point symmetry, comparable or even larger than the one of the most symmetric crystalline systems (cubic, 48 point symmetry operators). For example, N = 2n rototranslation symmetry operators connect the atoms of the (n,0) nanotubes. This symmetry is fully exploited in the CRYSTAL code. As a result, ab initio quantum mechanical large basis set calculations of carbon nanotubes containing more than 150 atoms in the unit cell become very cheap, because the irreducible part of the unit cell reduces to two atoms only. The nanotube symmetry is exploited at three levels in the present implementation. First, for the automatic generation of the nanotube structure (and then of the input file for the SCF calculation) starting from a two‐dimensional structure (in the specific case, graphene). Second, the nanotube symmetry is used for the calculation of the mono‐ and bi‐electronic integrals that enter into the Fock (Kohn‐Sham) matrix definition. Only the irreducible wedge of the Fock matrix is computed, with a saving factor close to N. Finally, the symmetry is exploited for the diagonalization, where each irreducible representation is separately treated. When M atomic orbitals per carbon atom are used, the diagonalization computing time is close to Nt, where t is the time required for the diagonalization of each 2M × 2M matrix. The efficiency and accuracy of the computational scheme is documented. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2010
Theoretical study on nonlinear optical properties of the Li+[calix[4]pyrrole]Li−dimer, trimer and its polymer with diffuse excess electrons
Authors: Yu Guang Tao , Chen Wei , Gu Feng Long , Aoki Yuriko 
Published: July 2009

AbstractThe static (hyper)polarizabilities of the dimer and trimer with diffuse excess electrons, [Li+[calix[4]pyrrole]Li−]n, are firstly investigated by the DFT(B3LYP) method in detail. For the dimer and trimer, a Li atom inside each calix[4]pyrrole unit is ionized to form a diffuse excess electron. The results show that the dimer and trimer containing two and three excess electrons, respectively, have very large first hyperpolarizablities as 2.3 × 104 and 4.0 × 104 au, which are 30 and 40 times larger than that of the corresponding [calix[4]pyrrole]n (n = 2, 3) without Li atom. Also, β values of dimer and trimer are twice and four times as large as that of monomer containing one excess electron. Obviously, not only excess electron but also the number of excess electron plays an important role in increasing the first hyperpolarizability. Moreover, the (hyper)polarizabilities of the [Li+[calix[4]pyrrole]Li−]n polymer are investigated at ab initio level by using the elongation finite‐field (elongation FF) method. All the oligomers of the [Li+[calix[4]pyrrole]Li−]n with many excess electrons exhibit very large first hyperpolarizability and large second hyperpolarizability. The present investigation shows that by introducing several and more excess electrons into the nonlinear optical (NLO) materials will be an important strategy for improving their NLO properties, which will be helpful for design of NLO materials. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2010
Osteology of the Graveldiver Scytalina cerdale (Perciformes: Zoarcoidei: Scytalinidae)
Authors: Hilton Eric J. 
Published: July 2009

AbstractThe Graveldiver, Scytalina cerdale, is a small, poorly known burrowing fish from the intertidal and subtidal zones of the west coast of North America, ranging from south‐central California to Alaska. This is the sole member of the family Scytalinidae, which is included in the Zoarcoidei. Although it was described over 120 years ago, it is rare in natural history collections and its anatomy is only imperfectly known. This article describes and illustrates the skeletal anatomy of S. cerdale based on newly prepared cleared and stained specimens. Many points of its anatomy are clarified or corrected (e.g., presence of the intercalars and ribs, in contrast to their reported absence) or described for the first time (e.g., structure of its gill‐arches). Previous hypotheses of its systematic placement within the Zoarcoidei are discussed. On the basis of preliminary comparisons, S. cerdale may have phylogenetic affinity with at least some members of the family Stichaeidae (e.g., Xiphister). However, further study is needed on the anatomy and inter‐relationships of the families of the Zoarcoidei before any conclusions can be made. J. Morphol., 2009. © 2009 Wiley‐Liss, Inc.
Cervids with different vocal behavior demonstrate different viscoelastic properties of their vocal folds
Authors: Riede Tobias , Lingle Susan , Hunter Eric J. , Titze Ingo R. 
Published: July 2009

AbstractThe authors test the hypothesis that vocal fold morphology and biomechanical properties covary with species‐specific vocal function. They investigate mule deer (Odocoileus hemionus) vocal folds, building on, and extending data on a related cervid, the Rocky Mountain elk (Cervus elaphus nelsoni). The mule deer, in contrast to the elk, is a species with relatively little vocal activity in adult animals. Mule deer and elk vocal folds show the typical three components of the mammalian vocal fold (epithelium, lamina propria and thyroarytenoid muscle). The vocal fold epithelium and the lamina propria were investigated in two sets of tensile tests. First, creep rupture tests demonstrated that ultimate stress in mule deer lamina propria is of the same magnitude as in elk. Second, cyclic loading tests revealed similar elastic moduli for the vocal fold epithelium in mule deer and elk. The elastic modulus of the lamina propria is also similar between the two species in the low‐strain region, but differs at strains larger than 0.3. Sex differences in the stress–strain response, which have been reported for elk and human vocal folds, were not found for mule deer vocal folds. The laminae propriae in mule deer and elk vocal folds are comparatively large. In general, a thick and uniformly stiff lamina propria does not self‐oscillate well, even when high subglottic pressure is applied. If the less stiff vocal fold seen in elk is associated with a differentiated lamina propria it would allow the vocal fold to vibrate at high tension and high subglottic pressure. The results of this study support the hypothesis that viscoelastic properties of vocal folds varies with function and vocal behavior. J. Morphol., 2010. © 2009 Wiley‐Liss, Inc.
Overexpression of the PDZ1 domain of PSD‐95 diminishes ischemic brain injury via inhibition of the GluR6·PSD‐95·MLK3 pathway
Authors: Hu Shu‐Qun , Zhu Jie , Pei Dong‐Sheng , Zong Yan‐Yan , Yan Jing‐Zhi , Hou Xiao‐Yu , Zhang Guang‐Yi 
Published: July 2009

AbstractRecent studies have shown that kainate (KA) receptors are involved in neuronal cell death induced by seizure, which is mediated by the GluR6·PSD‐95·MLK3 signaling module and subsequent JNK activation. In our previous studies, we demonstrated the neuroprotective role of a GluR6 c‐terminus containing peptide against KA or cerebral ischemia‐induced excitotoxicity in vitro and in vivo. Here, we first report that overexpression of the PDZ1 domain of PSD‐95 protein exerts a protective role against neuronal death induced by cerebral ischemia‐reperfusion in vivo and can prevent neuronal cell death induced by oxygen‐glucose deprivation. Further studies show that overexpression of PDZ1 can perturb the interaction of GluR6 with PSD‐95 and suppress the assembly of the GluR6·PSD‐95·MLK3 signaling module and therefore inhibit JNK activation. Thus, it not only inhibits phosphorylation of c‐Jun and down‐regulates Fas ligand expression but also inhibits phosphorylation of 14‐3‐3 and decreases Bax translocation to mitochondria, decreases the release of cytochrome c, and decreases caspase‐3 activation. Overall, the essential role of the PDZ1 domain of PSD‐95 in apoptotic cell death in neurons provides an experimental foundation for gene therapy of neurodegenerative diseases with overexpression of the PDZ1 domain. © 2009 Wiley‐Liss, Inc.
Tissue neogenesis and STRO‐1 expression in immature and mature articular cartilage
Authors: Otsuki Shuhei , Grogan Shawn P. , Miyaki Shigeru , Kinoshita Mitsuo , Asahara Hiroshi , Lotz Martin K. 
Published: July 2009

AbstractThis study determined the potential for neotissue formation and the role of STRO‐1+ cells in immature versus mature articular cartilage. Cartilage explants from immature and mature bovine knee joints were cultured for up to 12 weeks and stained with safranin‐O, for type II collagen and STRO‐1. Bovine chondrocyte pellet cultures and murine knee joints at the age of 2 weeks and 3 months, and surgically injured cartilage, were analyzed for changes in STRO‐1 expression patterns. Results show that immature explants contained more STRO‐1+ cells than mature explants. After 8 weeks in culture, immature explants showed STRO‐1+ cell proliferation and newly formed tissue, which contained glycosaminoglycan and type II collagen. Mature cartilage explants showed only minimal cell expansion and neotissue formation. Pellet cultures with chondrocytes from immature cartilage showed increased glycosaminoglycan synthesis and STRO‐1+ staining, as compared to pellets with mature chondrocytes. The frequency of STRO‐1+ cells in murine knee joints significantly declined with joint maturation. Following surgical injury, immature explants had higher potential for tissue repair than mature explants. In conclusion, these findings suggest that the high percentage of STRO‐1+ cells in immature cartilage changes with joint maturation. STRO‐1+ cells have the potential to form new cartilage spontaneously and after tissue injury. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:96–102, 2010