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Same Plane (same + plane)
Selected AbstractsCrystal structure of a ternary mononuclear copper (II) complex: 4-chloro-3-methyl-6[(N-2-picolyl)-1,-iminomethyl]phenolato copper(II)perchlorateCRYSTAL RESEARCH AND TECHNOLOGY, Issue 5 2006S. M. Malathy Sony Abstract The complex crystallizes in monoclinic space group P21/n with unit cell parameters a = 7.295(4), b = 19.627(5), c = 12.770(4) Å, , = 101.25(4)º, V = 1793.2(12) Å3, Z = 4, , = 1.684 Mg/m3 at T = 293(2)K. The structure was solved by Patterson method and refined by full-matrix least-squares procedures to final R = 0.0387 using 2906 observed reflections. The asymmetric unit of the complex contains a mononuclear tridentate ligand, a perchlorate group and a methanol molecule. The compound crystallizes as parallel layers of polymeric complex bridged through perchloarate groups. The molecular CuN2OO,O,,2 chromophore involves an elongated rhombic octahedral structure and the Cu-ligand bond shows greater disparity. The five-membered chelate ring and the pyridine ring lie in the same plane while the six membered chelate ring assumes sofa conformation. A strong O-H,O inter molecular interaction plays a key role in the formation of dimer along b-axis. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Functional connections and epileptic spread between hippocampus, entorhinal cortex and amygdala in a modified horizontal slice preparation of the rat brainEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 10 2000Ron Stoop Abstract The hippocampus, the entorhinal cortex and the amygdala are interconnected structures of the limbic system that are implicated in memory and emotional behaviour. They demonstrate synaptic plasticity and are susceptible to development of temporal lobe epilepsy, which may lead to emotional and psychological disturbances. Their relative anatomical disposition has limited the study of neurotransmission and epileptic spread between these three regions in previous in vitro preparations. Here we describe a novel, modified-horizontal slice preparation that includes in the same plane the hippocampus, entorhinal cortex and amygdala. We found that, following application of bicuculline, each region in our preparation could generate spontaneous bursts that resembled epileptic interictal spikes. This spontaneous activity initiated in the hippocampal CA3/2 region, from where it propagated and controlled the activity in the entorhinal cortex and the amygdala. We found that this spontaneous bursting activity could spread via two different pathways. The first pathway comprises the well-known subiculum,entorhinal cortex,perirhinal cortex,amygdala route. The second pathway consists of a direct connection between the CA1 region and perirhinal cortex, through which the hippocampal bursting activity can spread to the amygdala while bypassing the entorhinal cortex. Thus, our experiments provide a new in vitro model of initiation and spread of epileptic-like activity in the ventral part of the limbic system, which includes a novel, fast and functional connection between the CA1 region and perirhinal cortex. [source] Numerical determination of 3D temperature fields in steel jointsFIRE AND MATERIALS, Issue 2-4 2004Jean-Marc Franssen Abstract A numerical study was undertaken to investigate the temperature field in steel joints and to compare the temperatures in the joints with the temperatures of the adjacent steel members on the hypothesis that the thermal protection is the same on the joint and in the members. Very brief information is given on the numerical model, supplemented with parametric studies made in order to determine the required level of discretization in the time and in the space domain. A simplified assumption for representing the thermal insulation is also discussed and validated. Different numerical analyses are performed, with a variation of the following parameters: (i) type of joints, from very simple to more complex configurations, with welds and/or bolts, all of them representing joints between elements located in the same plane; (ii) unprotected joints or protected by one sprayed material; (iii) ISO, hydrocarbon or one natural fire scenario. The fact that the thermal attack from the fire might be less severe because the joints are usually located in the corner of the compartment is not taken into account. Copyright © 2004 John Wiley & Sons, Ltd. [source] Crimp morphology in relaxed and stretched rat Achilles tendonJOURNAL OF ANATOMY, Issue 1 2007Marco Franchi Abstract Fibrous extracellular matrix of tendon is considered to be an inextensible anatomical structure consisting of type I collagen fibrils arranged in parallel bundles. Under polarized light microscopy the collagen fibre bundles appear crimped with alternating dark and light transverse bands. This study describes the ultrastructure of the collagen fibrils in crimps of both relaxed and in vivo stretched rat Achilles tendon. Under polarized light microscopy crimps of relaxed Achilles tendons appear as isosceles or scalene triangles of different size. Tendon crimps observed via SEM and TEM show the single collagen fibrils that suddenly change their direction containing knots. The fibrils appear partially squeezed in the knots, bent on the same plane like bayonets, or twisted and bent. Moreover some of them lose their D-period, revealing their microfibrillar component. These particular aspects of collagen fibrils inside each tendon crimp have been termed ,fibrillar crimps' and may fulfil the same functional role. When tendon is physiologically stretched in vivo the tendon crimps decrease in number (46.7%) (P < 0.01) and appear more flattened with an increase in the crimp top angle (165° in stretched tendons vs. 148° in relaxed tendons, P < 0.005). Under SEM and TEM, the ,fibrillar crimps' are still present, never losing their structural identity in straightened collagen fibril bundles of stretched tendons even where tendon crimps are not detectable. These data suggest that the ,fibrillar crimp' may be the true structural component of the tendon crimp acting as a shock absorber during physiological stretching of Achilles tendon. [source] Sonographic assessment of clubfootJOURNAL OF CLINICAL ULTRASOUND, Issue 5 2004Cosimo Gigante MD Abstract Purpose This study was performed to develop a standardized methodology for the sonographic assessment of clubfoot at birth and at the end of both conservative treatment and surgical correction. Methods Forty-two congenital clubfeet and 42 normal feet were examined sonographically in the position of spontaneous alignment and during passive manual correction. Scans along 4 planes provided information relevant to the assessment: sagittal posterior, sagittal anterior, coronal lateral, and transverse. Results Sagittal posterior sonograms demonstrated the progressive gain of dorsiflexion ability during the different steps of treatment for clubfoot. Sagittal anterior sonograms could not demonstrate the normal alignment of the navicular in clubfeet because of the bone's medial displacement. On transverse sonograms, the talar head and the medially displaced navicular may lie on the same plane, depending on the severity of the deformity. Coronal lateral sonograms provided for estimation of the relationships between the calcaneus and cuboid, which were described by the calcaneal-cuboid angle. Conclusions Sonography is a promising technique for assessment and monitoring of clubfoot during treatment. The method described here yields accurate and reproducible information about the anatomy of the nonossified clubfoot, helping the orthopedic team decide on appropriate treatment steps. © 2004 Wiley Periodicals, Inc. J Clin Ultrasound 32:235,242, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/jcu.20022 [source] Motifs in nucleic acids: Molecular mechanics restraints for base pairing and base stackingJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 1 2003Stephen C. Harvey Abstract In building and refining nucleic acid structures, it is often desirable to enforce particular base pairing and/or base stacking interactions. Energy-based modeling programs with classical molecular mechanics force fields do not lend themselves to the easy imposition of penalty terms corresponding to such restraints, because the requirement that two bases lie in or near the same plane (pairing) or that they lie in parallel planes (stacking) cannot be easily expressed in terms of traditional interactions involving two atoms (bonds), three atoms (angles), or four atoms (torsions). Here we derive expressions that define a collection of pseudobonds and pseudoangles through which molecular mechanics restraints for base pairing and stacking can be imposed. We have implemented these restraints into the JUMNA package for modeling DNA and RNA structures. JUMNA scripts can specify base pairing with a variety of standard geometries (Watson,Crick, Hoogsteen, wobble, etc.), or with user-defined geometries; they can also specify stacking arrangements. We have also implemented "soft-core" functions to modify van der Waals and electrostatic interactions to avoid steric conflicts in particularly difficult refinements where two backbones need to pass through one another. Test cases are presented to show the utility of the method. The restraints could be adapted for implementation in other molecular mechanics packages. © 2002 Wiley Periodicals, Inc. J Comput Chem 24: 1,9, 2003 [source] Surface-enhanced Raman scattering of 4,4,-dicyanobiphenyl on gold and silver nanoparticle surfacesJOURNAL OF RAMAN SPECTROSCOPY, Issue 6 2002Chung-ro Lee The adsorption behavior of 4,4,-dicyanobiphenyl (DCBP) on Ag and Au nanoparticle surfaces was studied by surface-enhanced Raman scattering (SERS). The absence of the ring CH band denoted a flat orientation of the biphenyl ring on Ag and Au. The red shift of the ,8a band indicated a direct ring ,-orbital interaction with the surfaces. The two benzene rings of DCBP appeared to lie on the same plane with a ,-type interaction upon adsorption on the surfaces. The ,(CN) bands were blue shifted in the Ag and Au SERS spectra by 2 and 22 cm,1, respectively from the ordinary Raman spectrum. The orientation of DCBP on the Ag and Au surfaces was analyzed by the relative enhancement factors of the vibrational bands based on the electromagnetic SERS selection rule. Copyright © 2002 John Wiley & Sons, Ltd. [source] Design of dual-band quadrifilar spiral antennas for satellite-mobile handsetsMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 4 2010R. A. Abd-Alhameed Abstract A novel quadrifilar spiral antenna is proposed for use in personal communications mobile terminals exploiting the "big low earth orbit" (big-LEO) satellite system (uplink 1.61,1.63 GHz; downlink 2.48,2.5 GHz). Feeding of the antenna from the outer periphery is proposed, to avoid the complexity and space requirements of a centre feed; an externally fed antenna can also be fed either by coaxial cables or stripline. Moreover, the hybrid phasing network and the matching network (if required) can be located outside and possibly printed in the same plane as the antenna structure. Versions of the design were investigated using the method of moments and in hardware realizations. These had a finite ground plane with air dielectric between the spirals and the ground plane. Performance suitable for satellite mobile system applications was demonstrated, including dual-band matching. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:987,990, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25090 [source] Rubidium dimolybdate, Rb2Mo2O7, and caesium dimolybdate, Cs2Mo2O7ACTA CRYSTALLOGRAPHICA SECTION C, Issue 7 2006Zoya A. Solodovnikova The crystal structures of dirubidium heptaoxodimolybdate, Rb2Mo2O7, and dicaesium heptaoxodimolybdate, Cs2Mo2O7, in the space groups Ama2 and P21/c, respectively, have been determined for the first time by single-crystal X-ray diffraction. The structures represent two novel structure types of monovalent ion dimolybdates, A2Mo2O7 (A = alkaline elements, NH4, Ag or Tl). In the structure of Rb2Mo2O7, Mo atoms are on a twofold axis, on a mirror plane and in a general position. One of the Rb atoms lies on a twofold axis, while three others are on mirror planes. Two O atoms attached to the Mo atom on a mirror plane are located on the same plane. Rubidium dimolybdate contains a new kind of infinite Mo,O chain formed from linked MoO4 tetrahedra and MoO6 octahedra alternating along the a axis, with two terminal MoO4 tetrahedra sharing corners with each octahedron. The chains stack in the [001] direction to form channels of an approximately square section filled by ten-coordinate Rb ions. Seven- and eight-coordinate Rb atoms are located between chains connected by a c translation. In the structure of Cs2Mo2O7, all atoms are in general positions. The MoO6 octahedra share opposite corners to form separate infinite chains running along the c axis and strengthened by bridging MoO4 tetrahedra. The same Mo,O polyhedral chain occurs in the structure of Na2Mo2O7. Eight- to eleven-coordinate Cs atoms fill the space between the chains. The atomic arrangement of caesium dimolybdate has an orthorhombic pseudosymmetry that suggests a possible phase transition P21/c,Pbca at elevated temperatures. [source] The fungal metabolite austdiolACTA CRYSTALLOGRAPHICA SECTION C, Issue 4 2003Leonardo Lo Presti The title compound, (7R,8S)-7,8-dihydroxy-3,7-dimethyl-6-oxo-7,8-dihydro-6H -isochromene-5-carbaldehyde, C12H12O5, is a trans -vicinal diol. Of the two fused rings, which lie approximately in the same plane, the pyran ring is almost perfectly planar, while the cyclohexenone ring adopts a slightly distorted half-chair conformation. The crystal packing is dictated by two strong intermolecular O,H,O interactions, one involving hydroxy and keto groups, the other involving two hydroxy groups. Molecules are linked together through twofold axes, forming zigzag ribbons extended along the a axis. [source] 2-(N,N -Diphenylamino)benzoic acidACTA CRYSTALLOGRAPHICA SECTION C, Issue 8 2001Anna Bou Shaped like a distorted propeller, molecules of the title compound, C19H15NO2, form centrosymmetric dimers in the crystalline phase in which the carboxy groups are linked through two hydrogen bonds. These dimers are arranged in columns held together via dispersive interactions between the phenyl moieties. The N atom and the three surrounding C atoms lie almost in the same plane, which implies that the lone electron pair of the N atom is involved in conjugation with the , systems of the phenyl fragments. [source] 2,4,6-Tris[2-(trimethylsilyl)ethynyl]-1,3,5-triazene: a novel precursor to C,N two-dimensional structuresACTA CRYSTALLOGRAPHICA SECTION C, Issue 11 2000John Kouvetakis The title structure, C18H27N3Si3, consists of separate molecules arranged in sheets parallel to the ab plane. In each molecule, the central (CN)3 ring, the ethynyl units, and the Si atoms lie in the same plane. Typical C,C and C,N bond distances are 1.197,(5) and 1.42,(4),Å, respectively. The angles inside the (CN)3 ring range from 114,(3) to 125,(3)° and the acetylenic branches are nearly linear. [source] | ||||||||||||||||