bluuebunny/crossref_metadata_2025_split huggingface dataset:
Connections of the retrosplenial granular b cortex in the rat
Authors: Van Groen Thomas , Wyss J. Michael 
Published: June 2003

AbstractAlthough the retrosplenial granular b cortex (Rgb) is situated in a critical position between the hippocampal formation and the neocortex, surprisingly few studies have examined its connections carefully. The present experiments use both anterograde and retrograde tracing techniques to characterize the connections of Rgb. The main cortical projections from Rgb are to the caudal part of the anterior cingulate cortex, area 18b, retrosplenial granular a cortex (Rga), and postsubiculum, and less dense terminal fields are present in the prelimbic and caudal occipital cortices. The major subcortical projections are to the anterior thalamic nuclei and the rostral pontine nuclei, and very small terminal fields are present in the caudal dorsomedial part of the striatum, the reuniens and reticular nuclei of the thalamus, and the mammillary bodies. Contralaterally, Rgb primarily projects to itself, i.e., homotypically, and more sparsely projects to Rga and postsubiculum. In general, the axons from Rgb terminate ipsilaterally in cortical layers I and III–V and contralaterally in layer V, with a smaller number of terminals in layers I and VI. Thalamic projections from Rgb target the anteroventral and laterodorsal nuclei of the thalamus, with only a few axons terminating in the anterodorsal nucleus, the reticular nucleus, and the nucleus reuniens of the thalamus. Rgb is innervated by the anterior cingulate cortex, precentral agranular cortex, cortical area 18b, dorsal subiculum, and postsubiculum. Subcortical projections to Rgb originate mainly in the claustrum, the horizontal limb of the diagonal band of Broca, and the anterior thalamic nuclei. These data demonstrate that, in the rat, Rgb is a major nodal point for the integration and subsequent distribution of information to and from the hippocampal formation, the midline limbic and visual cortices, and the thalamus. Thus, similarly to the entorhinal cortex, Rgb in the rat is a prominent gateway for information exchange between the hippocampal formation and other limbic areas of the brain. J. Comp. Neurol. 463:249–263, 2003. © 2003 Wiley‐Liss, Inc.
Distribution of high affinity choline transporter immunoreactivity in the primate central nervous system
Authors: Kus Laura , Borys Ewa , Ping Chu Ya , Ferguson Shawn M. , Blakely Randy D. , Emborg Marina E. , Kordower Jeffrey H. , Levey Allan I. , Mufson Elliott J. 
Published: June 2003

AbstractA mouse monoclonal antibody (clone 62‐2E8) raised against a human recombinant high‐affinity choline transporter (CHT)‐glutathione‐S‐transferase fusion protein was used to determine the distribution of immunoreactive profiles containing this protein in the monkey central nervous system (CNS). Within the monkey telencephalon, CHT‐immunoreactive perikarya were found in the striatum, nucleus accumbens, medial septum, vertical and horizontal limb nuclei of the diagonal band, nucleus basalis complex, and the bed nucleus of the stria terminalis. Dense fiber staining was observed within the islands of Calleja, olfactory tubercle, hippocampal complex, amygdala; moderate to light fiber staining was seen in iso‐ and limbic cortices. CHT‐containing fibers were also present in sensory and limbic thalamic nuclei, preoptic and hypothalamic areas, and the floccular lobe of the cerebellum. In the brainstem, CHT‐immunoreactive profiles were observed in the pedunculopontine and dorsolateral tegmental nuclei, the Edinger‐Westphal, oculomotor, trochlear, trigeminal, abducens, facial, ambiguus, dorsal vagal motor, and hypoglossal nuclei. In the spinal cord, CHT‐immunoreactive ventral horn motoneurons were seen in close apposition to intensely immunoreactive C‐terminals at the level of the cervical spinal cord. CHT immunostaining revealed a similar distribution of labeled profiles in the aged human brain and spinal cord. Dual fluorescent confocal microscopy revealed that the majority of CHT immunoreactive neurons contained the specific cholinergic marker, choline acetyltransferase, at all levels of the monkey CNS. The present observations indicate that the present CHT antibody labels cholinergic structures within the primate CNS and provides an additional marker for the investigation of cholinergic neuronal function in aging and disease. J. Comp. Neurol. 463:341–357, 2003. © 2003 Wiley‐Liss, Inc.
Missplicing resulting from a short deletion in the reelin gene causes reeler‐like neuronal disorders in the mutant shaking rat Kawasaki
Authors: Kikkawa Satoshi , Yamamoto Tatsuro , Misaki Kazuyo , Ikeda Yayoi , Okado Haruo , Ogawa Masaharu , Woodhams Peter L. , Terashima Toshio 
Published: June 2003

AbstractThe shaking rat Kawasaki (SRK) is an autosomal recessive mutant that exhibits reeler‐like abnormal locomotor behaviors. The murine reeler mutants arise from several mutations in the specific gene called reelin, which result in defects of Reelin expression or secretion in the cerebral cortex and other regions of CNS. To address the issue of whether the SRK mutation also arises from a mutation in reelin, we analyzed the reelin gene in SRK. Northern analysis of reelin mRNA from normal rats showed that rat reelin was expressed as a ∼12‐kb transcript in both the cerebrum and the cerebellum, whereas reelin expression was markedly reduced in the SRK brains. In situ hybridization analysis showed that reelin mRNA in the SRK brains was expressed in Cajal‐Retzius cells in the marginal zone of the cerebral cortex and outer granular cells in the cerebellar cortex in similar manners to normal controls, but its expression was considerably reduced. On Western blotting and immunohistochemical analyses using antibodies specific for the Reelin protein, no immunoproduct was recognized in the cerebral and cerebellar cortices. From the cDNA sequences, we found a 64‐base heterologous sequence in SRK reelin, which contains a termination codon in the reading frame. Furthermore, genomic DNA analysis revealed that a 10‐base deletion, which contains a predicted splice donor site, occurred in the SRK genomic reelin gene, resulting in “read through” into the following intron in SRK. Thus, the SRK mutation is another type of mutation that lacks expression of the functional Reelin protein and, therefore, causes the reeler phenotype. J. Comp. Neurol. 463:303–315, 2003. © 2003 Wiley‐Liss, Inc.
Lazy eyes zebrafish mutation affects Müller glial cells, compromising photoreceptor function and causing partial blindness
Authors: Kainz Pamela M. , Adolph Alan R. , Wong Kwoon Y. , Dowling John E. 
Published: June 2003

AbstractA behavioral assay based on the optokinetic reflex was used to screen chemically mutagenized zebrafish larvae for deficits in visual function. A homozygous recessive mutation, lazy eyes (lze), was isolated based on the observation that 5‐day postfertilization (dpf) mutants displayed weaker and less frequent eye movements than wild‐type fish in response to moving stripes. Electroretinographic (ERG) recordings revealed that mutants had severely reduced a‐ and b‐wave amplitudes relative to wild‐type fish, indicating outer retinal dysfunction. Retinal lamination and cellular differentiation were normal in the lze retina; however, mutant photoreceptor cells had small outer segments and pyknotic nuclei were occasionally observed in the outer retina and the marginal zone of lze. Cone, rod, amacrine, bipolar, and Müller cell marker analyses indicated that the typical lze retina contained fewer rod photoreceptors and fewer Müller cells than wild‐type fish at 5 dpf. At 3 dpf, however, mutant retinas had normal numbers of rod photoreceptors and Müller cells, suggesting that the initial differentiation of these cell types occurred normally. Rod photoreceptor histology was normal at this early stage, but Müller cells were often hypertrophied, suggesting that they were unhealthy. Constant light rearing of mutant animals accelerated the Müller cell degeneration, severely worsened the visual deficit, but had no obvious affect on the photoreceptors. When ERG responses and Müller cell degeneration from the same mutant animals were analyzed, the extent of the Müller cell loss matched closely the degree to which ERG responses were reduced. In summary, the lze gene appears to be required for Müller cell viability and normal visual function. The lze mutant may be a model for the study of the involvement of Müller cells in photoreceptor development and function. J. Comp. Neurol. 463:265–280, 2003. © 2003 Wiley‐Liss, Inc.
Nanocomposite Si/Diamond Layers: Room Temperature Visible‐Light Emitting Systems
Authors: Terranova M.L. , Sessa V. , Botti S. , Rossi M. , Motsnyi F.V. , Konchits A.A. , Lytvyn P.M. , Yukhymchuk V.O. 
Published: June 2003

AbstractVisible‐light emitting nanocomposite Si/diamond polycrystalline layers, produced by means of a hybrid CVD/powder‐flowing technique, have been investigated by atomic force microscopy (AFM), reflection high energy electron diffraction (RHEED), Raman spectroscopy, photoluminescence (PL), and electron spin resonance (ESR). The room temperature emission of the layers at 1.7 eV and 2.0–2.4 eV is dominated by the optical properties of the inserted Si nanoparticles (mean diameter 3.3 ± 0.5 nm). The density of the ESR active centers is N = (4 ± 2) × 1019 cm–3 with g = 2.0025 (T = 300 K). A study of the temperature‐dependent changes in the nature and localization of paramagnetic centers has been carried out by comparing the ESR signals taken at 300 K, 30 K, and 4.2 K. The ESR results suggest that the active centers originate from the dangling bonds induced in sp3‐coordinated C atoms by insertion of the Si nanoparticles. The g‐factor anisotropy, detected at 4.2 K, is consistent with the peculiarities of dipole–dipole interactions in structures with low dimensionality.
Formation of Nano SiC Particles by Laser‐Assisted CVD
Authors: Kamlag Y. , Goossens A. , Colbeck I. , Schoonman J. 
Published: June 2003

AbstractNanocrystals of cubic silicon carbide (SiC) are formed using laser‐assisted gas‐phase synthesis. A CO2 laser beam is mechanically chopped to obtain pulsed infrared (IR) excitation. Silane (SiH4) and acetylene (C2H2) have been used as precursors. The SiC particles formed adopt the zinc blende crystal structure (β‐phase) with an average primary particle size of about 12 nm. Higher chopping frequencies yield smaller crystals. Oxidation and subsequent etching with HF removes the oxide shell, leading to further reduction of the particle size to 4 nm.
Deposition of Conductive Ru and RuO2 Thin Films Employing a Pyrazolate Complex [Ru(CO)3(3,5‐(CF3)2‐pz)]2 as the CVD Source Reagent
Authors: Song Y.‐H. , Chen Y.‐L. , Chi Y. , Liu C.‐S. , Ching W.‐L. , Kai J.‐J. , Chen R.‐S. , Huang Y.‐S. , Carty A.J. 
Published: June 2003

AbstractThe reaction of Ru3(CO)12 with three equivalent of 3,5‐bis(trifluoromethyl) pyrazole [(3,5‐(CF3)2‐pz)H] at 180 °C produces the double pyrazolate‐bridged ruthenium complex [Ru(CO)3(3,5‐(CF3)2‐pz)]2, (1), in high yield. This ruthenium complex has been characterized by spectroscopic methods, revealing a molecular structure similar to that of the diosmium analogue [Os(CO)3(3,5‐(CF3)2‐pz)]2. Thermogravimetric analysis (TGA) of complex 1 showed an enhanced volatility compared to the parent carbonyl compound Ru3(CO)12 and the closely related, unsaturated 3,5‐di‐tert‐butyl pyrazole complex (2) [Ru2(CO)5(3,5‐t‐Bu2‐pz)2]. Using complex 1 as the CVD source reagent, ruthenium metal with a preferred (002) orientation can be deposited at 400 °C using H2 as the carrier gas. If, however, O2 is used as the carrier gas, RuO2 thin films with a (101) orientation are obtained. The as‐deposited metal thin films were characterized by various surface techniques, as well as by electrical resistivity measurements.
Gas Phase Study of Systems for the CVD of Silver
Authors: Haase T. , Kohse‐Höinghaus K. , Atakan B. , Schmidt H. , Lang H. 
Published: June 2003

AbstractSuitable strategies for the deposition of silver require knowledge of the interplay of gas phase and surface chemistry, hence the gas phase of several potential silver(I) precursor systems have been analyzed by molecular beam mass spectrometry. Specifically, the decomposition of silver(I) trifluoroacetate, silver(I) pentafluoropropionate, (trifluoroacetato)bis(tri‐n‐butylphosphine) silver(I), and (pentafluoropropionato)bis(tri‐n‐butylphosphine) silver(I) have been investigated under hot‐wall CVD conditions. The experiments show that, under the conditions investigated, the silver carboxylates [AgO2CR] (R = CF3, C2F5) are not suitable, while the phosphane‐stabilized silver(I) carboxylates [(n‐Bu3P)2AgO2CR] (R = CF3, C2F5) are promising candidates. The thermal stability and potential formation mechanisms of the observed silver‐containing fragments are discussed.
Synthetic Strategies for Dehydrobenzo[n]annulenes
Authors: Marsden Jeremiah A. , Palmer Grant J. , Haley Michael M. 
Published: June 2003

AbstractDehydrobenzoannulenes have accrued great interest due to their potential uses such as hosts for binding guest molecules and precursors to fullerenes and other carbon‐rich materials, as well as their unique properties such as conductivity or superconductivity and nonlinear optical effects. These systems have seen numerous synthetic strategies employed in their construction over the past 50 years. As alkyne chemistry has developed more recently, annulene networks with greater complexity have been possible and the field has seen a vast resurgence. This article gives an account of synthetic methods developed for the preparation of annulenic systems and describes some of the interesting observed properties. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
(Schiff‐base)vanadium(V) Complex‐Catalyzed Oxidations of Substituted Bis(homoallylic) Alcohols − Stereoselective Synthesis of Functionalized Tetrahydrofurans
Authors: Hartung Jens , Drees Simone , Greb Marco , Schmidt Philipp , Svoboda Ingrid , Fuess Hartmut , Murso Alexander , Stalke Dietmar 
Published: June 2003

AbstractVanadium(V) complexes 4 have been prepared from tridentate Schiff‐base ligands 3 and VO(OEt)3. All vanadium(V) compounds were characterized (IR, UV/Vis, and 51V NMR spectroscopy, and in selected examples by X‐ray diffraction analysis) and were applied as oxidation catalysts for the stereoselective synthesis of functionalized tetrahydrofurans 2 starting from substituted bis(homoallylic) alcohols 1 (mono‐ or trisubstituted C−C double bonds). Oxidation of secondary or tertiary 1‐alkyl‐, 1‐vinyl‐, or 1‐phenyl‐substituted 5,5‐dimethyl‐4‐penten‐1‐ols under optimized conditions [TBHP as primary oxidant and 1,2‐(amino)indanol‐derived vanadium(V) reagent 4g as catalyst] provided 2,5‐cis‐configured tetrahydrofurans in synthetically useful yields and diastereoselectivities (22−96% de). On the other hand, trans‐disubstituted oxolanes (62%−96 de) were obtained from oxidations of 2‐ or 3‐alkyl‐ and 2‐ or 3‐phenyl‐substituted 5,5‐dimethyl‐4‐penten‐1‐ols bis(homoallylic) alcohols. Treatment of 4‐penten‐1‐ols (i.e. substrates with monosubstituted olefinic π‐bonds) with TBHP and catalytic amounts of vanadium(V) complex 4g furnished trans‐disubstituted tetrahydrofurans as major products (20−96% de), no matter whether an alkyl or a phenyl substituent was located in position 1, 2, or 3 of the alkenol chain. The mechanism of this reaction has been investigated in detail. Based on results from 51V NMR spectroscopy and competition kinetics, it proceeds by a transition metal−peroxy pathway. In an initial step, TBHP coordinates to, for example, N‐(2‐oxidophenyl)salicylideniminato‐derived vanadium complex 4a. Subsequent alkenol binding gives rise to a “loaded” vanadium(V) peroxy complex (e.g. 60) which facilitates diastereoselective oxygen transfer, presumably onto a coordinated substrate. This step leads to the formation of functionalized tetrahydrofurans as major products. TBHP binding to the remaining vanadium(V) complex then allows a regeneration of the active oxidant, for example peroxy complex 57. The origin of the observed diastereoselectivity in this oxidation has been studied in an independent stereochemical analysis. Thus, diastereomerically enriched epoxy alcohol (1R,4R)‐10 was prepared. Its treatment with 1,2‐(amino)indanol‐derived vanadium complex 4g affords a 91:9 mixture of cis‐2‐(1‐hydroxy‐1‐methylethyl)‐5‐(phenyl)tetrahydrofuran (cis‐6) and cis‐2,2‐dimethyl‐6‐(phenyl)tetrahydropyran‐3‐ol (cis‐7). Similarly, a 39:61 mixture of heterocycles trans‐6 and trans‐7 was obtained from epoxy alcohol (1S,4R)‐10, if treated with Lewis acid 4g. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Application of Nim‐2,6‐Dimethoxybenzoyl Histidine in Solid‐Phase Peptide Synthesis
Authors: Zaramella Simone , Strömberg Roger , Yeheskiely Esther 
Published: June 2003

AbstractFmoc‐histidine derivatives protected with 2,6‐dimethoxybenzoyl (2,6‐Dmbz) units, either on the τ‐ (1) or on the π‐position (2) of the imidazole residue, have been prepared and applied to the synthesis of the dipeptide Fmoc‐His(2,6‐Dmbz)‐Val‐OMe, with high coupling efficiencies (99 and 95%, respectively) and low racemization (0.3 and 0.1%, respectively), as ascertained by HPLC analysis on the fully protected dipeptides. In addition, the hexapeptide H‐Ala‐Ser‐Val‐His‐Val‐Phe‐OH (I) has been synthesized on a solid support employing the novel building blocks 1 and 2 as well as commercially available Fmoc‐His(τ‐Trt)‐OH (3). The crude deprotected products were analyzed by reverse‐phase HPLC and mass spectrometry, which indicated that when the τ‐protected derivatives 1 and 3 were employed the products were of comparable quality (93−94% major peak). The hexapeptide synthesized with the π‐protected histidine 2 was contaminated with a product corresponding to 2,6‐Dmbz‐His‐Val‐Phe‐OH (12), which was probably formed through the intramolecular acyl transfer of a 2,6‐Dmbz unit from the π‐nitrogen atom to the α‐amino group of the N‐terminal histidine unit upon removal of the Fmoc group. This side reaction was insignificant (less than 0.5%) when using the τ‐protected derivative 1. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Syntheses and UV/Vis Properties of Amino‐Functionalized Fulgimides
Authors: Otto Bernhard , Rück‐Braun Karola 
Published: June 2003

AbstractFunctionalized fulgimides are regarded as a promising class of photochromic compounds for modulating the structure and function of biomolecules. A new synthetic route to fulgimides bearing amino‐functionalized substituents at the imide nitrogen atom has been developed. The synthesis of the fulgimides has been achieved by base‐catalyzed cyclization of phenacyl esters of the succinamic acids derived from fulgides and N‐Boc‐protected alkyl‐ and aryl‐substituted diamines with triethylamine or tert‐butyllithium. The UV/Vis spectroscopic data and the photochromic properties of these new compounds have been studied. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Diastereoselective Synthesis of 1‐Benzyltetrahydroisoquinoline Derivatives from Amino Acids by 1,4 Chirality Transfer
Authors: Zawadzka Anna , Leniewski Andrzej , Maurin Jan K. , Wojtasiewicz Krystyna , Siwicka Aleksandra , Blachut Dariusz , Czarnocki Zbigniew 
Published: June 2003

AbstractL‐Amino acids (L‐Ala, L‐Phe, L‐Val, L‐Pro) were used as a source of chirality in the diastereoselective synthesis of tetrahydroisoquinoline derivatives. The key step was the Pictet−Spengler condensation of ketoamides 4 and 10, which proceeded under very mild conditions. L‐Ala, L‐Phe and L‐Val gave rise the R‐configuration at the newly formed stereogenic center. Surprisingly, L‐Pro gave the opposite result. The stereochemistry of 6d and 12a were established on the basis of X‐ray crystallographic data. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis of Novel Tetrahydropyran‐Based Dipeptide Isosters by Overman Rearrangement of 2,3‐Didehydroglycosides
Authors: Kriek Nicole M. A. J. , Hout Elise van der , Kelly Paskal , Meijgaarden Krista E. van , Geluk Annemieke , Ottenhoff Tom H. M. , Marel Gijs A. van der , Overhand Mark , Boom Jacques H. van , Valentijn A. Rob P. M. , Overkleeft Herman S. 
Published: June 2003

AbstractDifferently functionalized tetrahydropyran‐based dipeptide isosters have been efficiently synthesized from 3,4,6‐tri‐O‐acetyl‐D‐glucal. Analogues of the hsp65 p2−13 epitope of Mycobacterium tuberculosis and Mycobacterium leprae were prepared by replacement of the Ala−Tyr or Glu−Glu moiety in the native dodecapeptide with the prepared dipeptide isosters. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Mechanism of Selective and Unselective Enclathration by a Host Compound Possessing Open, Flexible Host Frameworks
Authors: Nakano Kazunori , Mochizuki Eiko , Yasui Nobuyoshi , Morioka Kyoichi , Yamauchi Yukinori , Kanehisa Nobuko , Kai Yasushi , Yoswathananont Nungruethai , Tohnai Norimitsu , Sada Kazuki , Miyata Mikiji 
Published: June 2003

AbstractMolecular recognition of o‐, m‐, and p‐xylenes (oX, mX, and pX) through enclathration of cholic acid (CA) is described. All of the xylenes give lattice inclusion crystals with CA, and crystallographic studies reveal that they are included in different open host frameworks. In particular, oX has two polymorphs, depending on the recrystallization temperatures. Competitive recrystallization from mixtures of xylenes resulted in selective enclathrations and the formation of racemic mixed crystals. In the presence of an equimolar amount of oX, CA selectively includes mX or pX in the host frameworks, which are identical to those obtained from the pure mX or pX, respectively. The low affinity of oX is explained in terms of a lower stability of CA·oX than of the other two complexes, as judged from the low PCcavity, the volume ratio of the guest compound to the host cavity. Meanwhile, mixtures of mX and pX yield inclusion crystals that accommodate both of the guests. These have the same open host framework as obtained from pure mX, and the guest components are disordered statically in the host cavity. The ratios of the xylene mixtures in the single crystals are similar to those in the original recrystallization mixtures, and also in the bulk crystals, indicating that CA forms mixed crystals of mX and pX. This non‐selectivity is attributed to the similar stabilities of CA·mX and CA·pX, according to the moderate PCcavity. The inclusion behavior of CA from mixtures of xylenes is quite similar to chiral recognition by diastereomer‐salt methods. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)