bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interhemispheric connections of the ventral premotor cortex in a new world primate
Authors: Dancause Numa , Barbay Scott , Frost Shawn B. , Mahnken Jonathan D. , Nudo Randolph J. 
Published: October 2007

AbstractThis study describes the pattern of interhemispheric connections of the ventral premotor cortex (PMv) distal forelimb representation (DFL) in squirrel monkeys. Our objectives were to describe qualitatively and quantitatively the connections of PMv with contralateral cortical areas. Intracortical microstimulation techniques (ICMS) guided the injection of the neuronal tract tracers biotinylated dextran amine or Fast blue into PMv DFL. We classified the interhemispheric connections of PMv into three groups. Major connections were found in the contralateral PMv and supplementary motor area (SMA). Intermediate interhemispheric connections were found in the rostral portion of the primary motor cortex, the frontal area immediately rostral and ventral to PMv (FR), cingulate motor areas (CMAs), and dorsal premotor cortex (PMd). Minor connections were found inconsistently across cases in the anterior operculum (AO), posterior operculum/inferior parietal cortex (PO/IP), and posterior parietal cortex (PP), areas that consistently show connections with PMv in the ipsilateral hemisphere. Within‐case comparisons revealed that the percentage of PMv connections with contralateral SMA and PMd are higher than the percentage of PMv connections with these areas in the ipsilateral hemisphere; percentages of PMv connections with contralateral M1 rostral, FR, AO, and the primary somatosensory cortex are lower than percentages of PMv connections with these areas in the ipsilateral hemisphere. These studies increase our knowledge of the pattern of interhemispheric connection of PMv. They help to provide an anatomical foundation for understanding PMv's role in motor control of the hand and interhemispheric interactions that may underlie the coordination of bimanual movements. J. Comp. Neurol. 505:701–715, 2007. © 2007 Wiley‐Liss, Inc.
Neuropathogical features of a rat model for perinatal hypoxic‐ischemic encephalopathy with associated epilepsy
Authors: Kadam Shilpa D. , Dudek F. Edward 
Published: October 2007

AbstractHypoxic‐ischemic (HI) encephalopathy is an important neurological problem of the perinatal period. Little is known of the long‐term progression of HI insults or the maladaptive changes that lead to epilepsy. Using rats with unilateral carotid occlusion followed by hypoxia at postnatal day 7, this study provides an initial analysis of the epilepsy caused by a perinatal HI insult with chronic and continuous behavioral monitoring. The histopathology was investigated at postnatal day 30 and later at ≥6 months of age using cresyl violet, Timm, and rapid Golgi staining and immunocytochemistry. The resultant epilepsy showed an increase in seizure frequency over time, with a preponderance for seizure clusters and behavioral features of an ipsilateral cerebral syndrome. In addition to parasagittal infarcts and porencephalic cysts in severe lesions, columnar neuronal death was found with cytomegaly in isolated groups of dysmorphic cortical neurons. Cortical dysgenesis was seen in the form of deep laminar cell loss, microgyri, white matter hypercellularity, and blurring of the white and gray matter junction. Mossy fiber sprouting was not only detected in the atrophied ipsilateral dorsal hippocampus of HI rats with chronic epilepsy, but was also found in comparable grades in spared ipsi‐ and contralateral ventral hippocampi. The cortical lesions in this animal model show histological similarities with those found in humans after perinatal HI. The occurrence of cortical abnormalities that are associated with epilepsy in humans correlates with the consequent detection of spontaneous recurrent seizures. J. Comp. Neurol. 505:716–737, 2007. © 2007 Wiley‐Liss, Inc.
Control of Drug Release through the In Situ Assembly of Stimuli‐Responsive Ordered Mesoporous Silica with Magnetic Particles
Authors: Zhu Shenmin , Zhou Zhengyang , Zhang Di 
Published: October 2007

AbstractA site‐selective controlled delivery system for controlled drug release is fabricated through the in situ assembly of stimuli‐responsive ordered SBA‐15 and magnetic particles. This approach is based on the formation of ordered mesoporous silica with magnetic particles formed from Fe(CO)5 via the surfactant‐template sol‐gel method and control of transport through polymerization of N‐isopropyl acrylamide inside the pores. Hydrophobic Fe(CO)5 acts as a swelling agent as well as being the source of the magnetic particles. The obtained system demonstrates a high pore diameter (7.1 nm) and pore volume (0.41 cm3 g−1), which improves drug storage for relatively large molecules. Controlled drug release through the porous network is demonstrated by measuring the uptake and release of ibuprofen (IBU). The delivery system displays a high IBU storage capacity of 71.5 wt %, which is almost twice as large as the highest value based on SBA‐15 ever reported. In vitro testing of IBU loading and release exhibits a pronounced transition at around 32 °C, indicating a typical thermosensitive controlled release.
Singlet Oxygen in Microporous Silica Xerogel: Quantum Yield and Oxidation at the Gas–Solid Interface
Authors: Cantau Christophe , Pigot Thierry , Manoj Narayanapillai , Oliveros Esther , Lacombe Sylvie 
Published: October 2007

AbstractThe quantum yields of singlet oxygen (1O2) production (ΦΔ) and 1O2 lifetimes (τΔ) at the gas–solid interface in silica gel material are determined. Different photosensitizers (PS) are encapsulated in parallelepipedic xerogel monoliths (PS‐SG). PS were chosen according to their known photooxidation properties: 9,10‐dicyanoanthracene (DCA), 9,10‐anthraquinone (ANT), and a benzophenone derivative, 4‐benzoyl benzoic acid (4BB). These experiments are mainly based on time‐resolved 1O2 phosphorescence detection, and the obtained ΦΔ and τΔ values are compared with those of a reference sensitizer for 1O2 production, 1H‐phenalen‐1‐one (PN), included in the same xerogel. The trend between their ability to oxidize organic pollutants in the gas phase and their efficiency for 1O2 production is investigated through photooxidation experiments of a test pollutant dimethylsulfide (DMS). The ΦΔ value is high for DCA‐SG relative to the PN reference, whereas it is slightly lower for 4BB‐SG and for ANT‐SG. ΦΔ is related to the production of sulfoxide and sulfone as the main oxidation products for DMS photosensitized oxidation. Additional mechanisms, leading to CS bond cleaveage, appear to mainly occur for the less efficient singlet oxygen sensitizers 4BB‐SG and ANT‐SG.
Acid–Base Chemistry at the Ice Surface: Reverse Correlation Between Intrinsic Basicity and Proton‐Transfer Efficiency to Ammonia and Methyl Amines
Authors: Park Seong‐Chan , Kim Joon‐Ki , Lee Chang‐Woo , Moon Eui‐Seong , Kang Heon 
Published: October 2007

AbstractProton transfer from the hydronium ion to NH3, CH3NH2, and (CH3)2NH is examined at the surface of ice films at 60 K. The reactants and products are quantitatively monitored by the techniques of Cs+ reactive‐ion scattering and low‐energy sputtering. The proton‐transfer reactions at the ice surface proceed only to a limited extent. The proton‐transfer efficiency exhibits the order NH3>(CH3)NH2=(CH3)2NH, which opposes the basicity order of the amines in the gas phase or aqueous solution. Thermochemical analysis suggests that the energetics of the proton‐transfer reaction is greatly altered at the ice surface from that in liquid water due to limited hydration. Water molecules constrained at the ice surface amplify the methyl substitution effect on the hydration efficiency of the amines and reverse the order of their proton‐accepting abilities.
Optical and dielectric studies on pure and Ni2+, Co2+ doped single crystals of bis thiourea cadmium chloride
Authors: Uthrakumar R. , Vesta C. , Raj C. Justin , Dinakaran S. , Dhas Rani Christhu , Das S. Jerome 
Published: October 2007

AbstractGood quality single crystals of Ni2+, Co2+ ions doped Bisthiourea Cadmium Chloride (BTCC) are some of the excellent and efficient non‐linear optical materials grown from aqueous solution by slow evaporation method. The lattice parameters of the grown crystals are determined by single crystal X‐ray analysis. UV spectral analyses on these samples reveal the improved transparency of the doped crystals ascertaining the inclusion of metal ion in the lattice. FTIR spectral analysis carried out on the materials confirm the presence of functional groups. Dielectric measurements reveal that the dielectric constant of pure and doped crystals decreases with increase of frequency. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Growth and structural characterization of [ZnL(DMSO)]
Authors: Dong Wenkui , Ding Yujie 
Published: October 2007

AbstractA novel mononuclear zinc(II) complex [ZnL(DMSO)] (1) with chelating bisoxime ligand 4,4′‐dinitro‐2,2′‐[ethylenedioxybis(nitrilomethylidyne)]diphenol (H2L) was synthesized and structurally characterized by X‐ray crystallography. The complex crystallizes in the triclinic system, space group P‐1, with unit cell parameters a = 8.9730(16), b = 11.9080(18), c = 20.701(2) Å, α = 103.893(3), β = 101.975(3), γ = 90.029(2) and Z = 4. The Zinc(II) ion is five‐coordinated by four N2O2 donor atoms of L2‐ and one oxygen atom from DMSO molecule. Interestingly, the unit of cell contains two crystallographically independent but chemically identical mononuclear complexes. (© 2007 WILEY ‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Hydrothermal synthesis and crystal structure of a three‐dimensional polyoxovanadate
Authors: Ma Huiyuan , Wang Xiaodan , Dong Baoxia , Li Chunxiang , Wu Lizhou 
Published: October 2007

AbstractA three‐dimensional polyoxovanadate formulated as HV3O8·H2O has been synthesized by hydrothermal method. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Microhardness studies of nanocrystalline calcium tungstate
Authors: Anandakumar V. M. , Khadar M. Abdul 
Published: October 2007

AbstractNanocrystals of calcium tungstate (CaWO4) of three different grain sizes were synthesized through chemical precipitation technique and the grain sizes and crystal structure were determined using the broadening of X‐ray diffraction patterns and transmission electron microscopy. The microhardness of compacted pellets of nanocrystalline calcium tungstate (CaWO4) with different grain sizes were measured using a Vickers microhardness tester for various applied loads ranging from 0.049 N to 1.96 N. The values of microhardness showed significant reverse indentation size effect at low indentation loads. The microhardness data obtained for samples of different grain sizes showed grain size dependent strengthening obeying normal Hall‐Petch relation. The dependence of compacting pressure and annealing temperature on microhardness of the nanostructured sample with grain size of 13 nm were also studied. The samples showed significant increase in microhardness as the compacting pressure and annealing time were increased. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characterization of melt grown phthalic anhydride single crystal
Authors: Ramesh Babu R. , Sethuraman K. , Vijayan N. , Bhagavannarayana G. , Gopalakrishnan R. , Ramasamy P. 
Published: October 2007

AbstractThe bulk organic single crystal of phthalic anhydride (PA) was grown by vertical Bridgman technique. The structural perfection of the grown crystal was analysed by high resolution X‐ray diffraction (Multicrystal X‐ray diffractometry) studies. The thermal and mechanical properties have been studied. The second harmonic generation relative efficiency of Phthalic anhydride crystal is compared with KDP crystal. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Investigation on birefringence property in uniaxial crystal (Ca0.28Ba0.72)0.75(Sr0.60Ba0.40)Nb2O6
Authors: Gao Ch. Y. , Xia H. R. , Xu J. Q. , Si Sh. Ch. , Zhang H. J. , Wang J. Y. 
Published: October 2007

AbstractThe birefringence of (Ca0.28Ba0.72)0.75(Sr0.60Ba0.40)Nb2O6 crystal is measured basing on polarization‐ extinction method and conoscopic interference method. Experimental results show that the birefringence in this crystal is up to 10‐5, the natural birefringence in this crystal is (no ‐ne) = 5.89 x 10‐5 with the He‐Ne laser wavelength at 632.8nm and the birefringence grads with wavelength at 532nm is 5.68 x 10‐5, which indicate the good optical homogeneity of this crystal. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Study of crystalline perfection and thermal analysis of zinc cadmium thiocyanate single crystals grown in silica gel
Authors: Nisha Santha Kumari P. , Kalainathan S. , Bhagavannarayana G. 
Published: October 2007

AbstractZinc cadmium thiocyanate ZnCd(SCN)4 abbreviated as ZCTC is a bimetallic thiocyanate complex that exhibits excellent nonlinear optical property. Single crystals of ZCTC have been grown in silica gel by the process of diffusion. Colorless transparent crystals of size 12 mm x 2 mm x 1.3 mm have been obtained. High resolution X‐ray diffraction study was carried out to investigate the crystalline perfection of the grown crystal and the quality of the crystal was found to be quite good. Thermal stability of the grown crystal was investigated by thermogravimetric and differential thermal analyses. Fourier Transform Infrared spectrum was recorded to confirm the functional groups. Microhardness of the crystal is also studied. Being a nonlinear optical material, a comparative study of its second harmonic generation efficiency with urea has been made. (© 2007 WILEY ‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Shape‐controlled synthesis of ZnO architectures
Authors: Wang Debao , Song Caixia , Hu Zhengshui 
Published: October 2007

AbstractSeveral ZnO nanoarchitectures have been selectively prepared through hydrothermal method including urchin‐shaped, flower‐shaped, butterfly‐shaped, and cacti‐shaped microstructures. The influence of reaction temperature and the concentration of amphiphilic copolymer on the morphologies and shapes of ZnO samples have been studied. The samples were characterized using XRD, TEM, and SEM. It was found that ZnO nanorods or their assemblies were fabricated at higher temperature, whereas ZnO nanosheet architectures were produced at lower temperature. These flower‐shaped architectures possess high BET surface area of 27.43 m2/g. Room temperature UV‐VIS and PL spectra of the as‐obtained ZnO nanoarchitectures have been examined. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of active afterheater on the induction heating process in oxide Czochralski systems
Authors: Tavakoli M. H. , Samavat F. , Babaiepour M. 
Published: October 2007

AbstractDifferent shapes and orientations of an active afterheater for oxide Czochralski crystal growth systems are considered and corresponding results of electromagnetic field and volumetric heat generation have been computed using a finite element method (Flex‐PDE package). For the calculations, the eddy current in the induction coil (i.e. the self‐inductance effect) has been taken into account. The calculation results show the importance of an active afterheater, its shape as well as its geometry and position with respect to the crucible on the heat generation distribution in a CZ growth system. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Two organic‐inorganic hybrids with Keggin polyanions
Authors: Ma Huiyuan , Wang Xiaodan , Wang Fuping , Wu Lizhou 
Published: October 2007

AbstractTwo new Keggin polyoxometalates [Co(phen)3]2[SiW12O40]·6H2O (1) and (ppy)6 H4SiMo12O40·0.4H2O (2) (phen = 1,10′‐phenanthroline, ppy = 4‐(5‐phenylpyridin‐2‐yl)pyridine) have been synthesized by the hydrothermal method. Single crystal X‐ray analysis revealed that compound 1 crystallizes in the monoclinic crystal system with cell parameters of a = 13.344(2) Å, b = 17.191(3) Å, c = 22.002(4) Å, α = 90.00°, β = 99.566(2)°, γ = 90.00°, V = 4977 Å3, Z = 2, and compound 2 crystallizes in the triclinic crystal system with cell parameters of a = 11.297(2) Å, b = 12.341(3) Å, c = 19.354(4) Å, α = 107.60(3)°, β = 95.80(3)°, γ = 94.16(3)°, V = 2543.7(9) Å3, Z = 1. Both 1 and 2 represent organic ligand molecules and inorganic Keggin anions, which are further interconnected to a 3D framework by supramolecular interactions. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Serosal mesothelium retains vasculogenic potential
Authors: Kawaguchi Michiya , Bader David M. , Wilm Bettina 
Published: October 2007

AbstractMesothelia comprise the epithelial covering of coelomic organs and line the cavities in which they are housed. Mesothelia contribute to the vasculature of the heart and the intestinal tract by developmental processes of epithelial–mesenchymal transition (EMT), migration, and differentiation into endothelial cells, vascular smooth muscle cells, and pericytes. Here, we establish a novel in vitro system to analyze the differentiative potential of mesothelia. Using explants from serosal mesothelium (the mesothelial covering of the gut), we demonstrate that much of the developmental program observed in embryonic mesothelia is retained in the adult structure. Namely, processes of epithelial spreading, EMT, and differentiation into smooth muscle cells from these cells are observed. Interestingly, we were unable to stimulate endothelial cell differentiation using serum or various signaling factors. Taken together, these data reveal that differentiated serosal cells retain vasculogenic potential and provide a generalizable model for future studies on the developmental and differentiative capacity of the mesothelial cell type. Developmental Dynamics 236:2973–2979, 2007. © 2007 Wiley‐Liss, Inc.
Caenorhabditis elegans germ line: A model for stem cell biology
Authors: Albert Hubbard E. Jane 
Published: October 2007

AbstractLike many stem cell systems, the Caenorhabditis elegans germ line contains a self‐renewing germ cell population that is maintained by a niche. Although the exact cellular mechanism for self‐renewal is not yet known, three recent studies shed considerable light on the cell cycle behavior of germ cells, including a support for significant and plastic renewal potential. This review brings together the results of the three recent cell‐based studies, places them in the context of previous work, and discusses future perspectives for the field. Developmental Dynamics 236:3343–3357, 2007. © 2007 Wiley‐Liss, Inc.
Muscle stem cells and model systems for their investigation
Authors: Figeac Nicolas , Daczewska Malgorzata , Marcelle Christophe , Jagla Krzysztof 
Published: October 2007

AbstractStem cells are characterized by their clonal ability both to generate differentiated progeny and to undergo self‐renewal. Studies of adult mammalian organs have revealed stem cells in practically every tissue. In the adult skeletal muscle, satellite cells are the primary muscle stem cells, responsible for postnatal muscle growth, hypertrophy, and regeneration. In the past decade, several molecular markers have been found that identify satellite cells in quiescent and activated states. However, despite their prime importance, surprisingly little is known about the biology of satellite cells, as their analysis was for a long time hampered by a lack of genetically amenable experimental models where their properties can be dissected. Here, we review how the embryonic origin of satellite cells was discovered using chick and mouse model systems and discuss how cells from other sources can contribute to muscle regeneration. We present evidence for evolutionarily conserved properties of muscle stem cells and their identification in lower vertebrates and in the fruit fly. In Drosophila, muscle stem cells called adult muscle precursors (AMP) can be identified in embryos and in larvae by persistent expression of a myogenic basic helix–loop–helix factor Twist. AMP cells play a crucial role in the Drosophila life cycle, allowing de novo formation and regeneration of adult musculature during metamorphosis. Based on the premise that AMPs represent satellite‐like cells of the fruit fly, important insight into the biology of vertebrate muscle stem cells can be gained from genetic analysis in Drosophila. Developmental Dynamics 236:3332–3342, 2007. © 2007 Wiley‐Liss, Inc.
Genes involved in the RNA interference pathway are differentially expressed during sea urchin development
Authors: Song Jia L. , Wessel Gary M. 
Published: October 2007

AbstractRNA‐mediated interference (RNAi) is a conserved gene silencing mechanism that involves double‐stranded RNA as a signal to trigger the sequence‐specific degradation of target mRNA, resulting in posttranscriptional silencing and/or translational repression. Bioinformatic searches in the sea urchin genome database identified homologs of Drosha, DGCR5, Dicer, TRBP, Exportin‐5, and Argonautes. Quantitative, real‐time polymerase chain reaction indicated that all mRNA accumulate in eggs and in variable levels throughout early development. Whole‐mount in situ RNA hybridization showed that all of the important players of the RNAi silencing pathway have abundant mRNA accumulation in oocytes and eggs, but have distinct spatial and temporal expression patterns throughout development. Sequence analysis revealed that each of the four Argonautes examined contain conserved residues important for RNAseH activity within the Piwi domain. This study elucidated that genes involved in the RNAi silencing pathway have dynamic expression and, thus, may have regulatory roles during germ cell development and embryogenesis. Developmental Dynamics 236:3180–3190, 2007. © 2007 Wiley‐Liss, Inc.
High‐frequency ultrasonographic imaging of avian cardiovascular development
Authors: McQuinn Tim C. , Bratoeva Momka , DeAlmeida Angela , Remond Mathieu , Thompson Robert P. , Sedmera David 
Published: October 2007

AbstractThe chick embryo has long been a favorite model system for morphologic and physiologic studies of the developing heart, largely because of its easy visualization and amenability to experimental manipulations. However, this advantage is diminished after 5 days of incubation, when rapidly growing chorioallantoic membranes reduce visibility of the embryo. Using high‐frequency ultrasound, we show that chick embryonic cardiovascular structures can be readily visualized throughout the period of Stages 9–39. At most stages of development, a simple ex ovo culture technique provided the best imaging opportunities. We have measured cardiac and vascular structures, blood flow velocities, and calculated ventricular volumes as early as Stage 11 with values comparable to those previously obtained using video microscopy. The endocardial and myocardial layers of the pre‐septated heart are readily seen as well as the acellular layer of the cardiac jelly. Ventricular inflow in the pre‐septated heart is biphasic, just as in the mature heart, and is converted to a monophasic (outflow) wave by ventricular contraction. Although blood has soft‐tissue density at the ultrasound resolutions and developmental stages examined, its movement allowed easy discrimination of perfused vascular structures throughout the embryo. The utility of such imaging was demonstrated by documenting changes in blood flow patterns after experimental conotruncal banding. Developmental Dynamics 236:3503–3513, 2007. © 2007 Wiley‐Liss, Inc.