bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of mandibular landmarks from computed tomography and 3D digitizer data
Authors: Williams Frank L'Engle , Richtsmeier Joan T. 
Published: October 2003

AbstractWe recorded 3D coordinates for 28 mandibular landmarks from three‐dimensional reconstructions of CT axial slices using the image analysis program eTDIPS. The images were acquired from a pediatric series of human mandibles (neonate to 13 years of age) from the Bosma collection (Shapiro and Richtsmeier, 1997, Am. J. Phys. Anthropol. 103:415–416). To test the accuracy of these coordinate data, we recorded the same 28 landmarks directly on the Bosma mandibles using a Polhemus 3Space digitizer. The directly digitized landmarks serve as a gold standard upon which to evaluate the eTDIPS data. Standard deviations of landmark placement using eTDIPS show a greater degree of variation compared to the data gathered using the digitizer, although this error is more heavily concentrated in certain types of landmarks. All possible linear distances between unique pairs of landmarks were calculated, and like linear distances were compared between the two data collection methods. The absolute difference for all like linear distances ranged from 0.001–3.9 mm (mean = 0.377 mm; SD = 1.136), with the eTDIPS data being consistently larger than the digitizer coordinates. This study demonstrates that landmark coordinate data can be reliably collected from digital CT images of the human mandible. We define a set of mandibular landmarks useful in evaluating the effects of craniofacial disorders, growth and other biological processes. Clin. Anat. 16:494–500, 2003. © 2003 Wiley‐Liss, Inc.
Clinical anatomy of ligamentum nuchae
Authors: Mercer Susan R. , Bogduk Nikolai 
Published: October 2003

AbstractIn view of the disparities in the anatomical, clinical, and biomechanical literature this study was undertaken to reappraise the gross anatomy of ligamentum nuchae with the objective of providing an accurate anatomical basis for biomechanical studies and for clinical theories and practices. Ligamentum nuchae was studied by gross dissection in ten embalmed human adult cadavers and was found to be comprised of two structures: a dorsal raphe and a midline fascial septum. The dorsal raphe was formed by the interweaving of the right and left upper trapezius, splenius capitis, and rhomboid minor. It spanned the cervical spine and was firmly attached to the external occipital protuberance and to the spinous process of C7. The fascial septum consisted of dense connective tissue and ran ventrally from the midline raphe to be confluent with the interspinous ligaments and atlanto‐axial and atlanto‐occipital membranes. These findings agree with those anatomical descriptions that portray ligamentum nuchae as a two‐part structure but not with those studies in which it is characterized as a strong ligament attaching to all cervical spinous processes. Importantly, the findings of this study emphasize the need for clinical and biomechanical literature to portray the gross anatomy of ligamentum nuchae accurately. Clin. Anat. 16:484–493, 2003. © 2003 Wiley‐Liss, Inc.
Axillary arch: Potential cause of neurovascular compression syndrome
Authors: Mérida‐Velasco J.R. , Rodríguez Vázquez J.F. , Mérida Velasco J.A. , Sobrado Pérez J. , Jiménez Collado J. 
Published: October 2003

AbstractDuring routine bilateral dissection of 64 upper limbs in 32 adult human cadavers, four cases of an axillary arch, a muscular anomaly, were found. In one case, the axillary arch presented on both sides and in two cases it presented unilaterally on the right side. The innervation and relationships of the axillary arches are reported and the surgical significance of the anomaly is discussed. Clin. Anat. 16:514–519, 2003. © 2003 Wiley‐Liss, Inc.
The spinoglenoid ligament: An anatomic study
Authors: Demirkan Ahmet Fahir , Sargon Mustafa F. , Erkula Gurkan , Kiter Esat 
Published: October 2003

AbstractThe spinoglenoid ligament and its anatomic variations are described in 27 shoulders from 15 cadavers. In each shoulder one or two distinct spinoglenoid ligaments originated from the base of the spine of the scapula; they inserted on the neck of the scapula or the shoulder joint capsule. In the 19 shoulders in which only one spinoglenoid ligament was present, it inserted into the neck of the scapula in 14 cases and into the shoulder joint capsule in five instances. In the eight shoulders in which there were two ligaments, one inserted into the neck of the scapula and the other into the shoulder joint capsule. We did not observe any hypertrophic spinoglenoid ligaments that may have compressed the suprascapular nerve. Clin. Anat. 16:511–513, 2003. © 2003 Wiley‐Liss, Inc.
Prevalence of osteophytes associated with the acromion and acromioclavicular joint
Authors: Mahakkanukrauh Pasuk , Surin Patcharin 
Published: October 2003

AbstractOsteophytes as a stigma for shoulder impingement syndrome and osteoarthritis of the acromioclavicular (AC) joint were studied on the acromions and AC joints in 346 skeletons (230 males; 116 females), ranging in age from 15–100 years. Osteophytes were found on 28.9% (200/692) of the acromions, mostly on the anteroinferior aspect (54%; 108/200). Of these 28.9%, 87% (174/200) were of the traction type and 13% (26/200) of the claw type. Regarding the clavicles, 11.6% (80/692) had osteophytes on the articular facets of their lateral ends; all were of the traction type. There were statistically more osteophytes on the right than on the left side of both acromion and clavicle (P < 0.05). The occurrence of osteophytes and increasing age were significantly correlated (r = 0.65, P < 0.001). No gender differences were noted in the frequency of osteophytes on acromions or clavicles. These data should prove beneficial to clinicians in planning a proper course of treatment for patients suffering from painful conditions of the shoulder. Clin. Anat. 16:506–510, 2003. © 2003 Wiley‐Liss, Inc.
Evidence for the Formation of Singly Bonded Dimers During the Reductive Electrochemistry of Methanofullerenes
Authors: Oçafrain Maïténa , Herranz M. Ángeles , Marx Lucien , Thilgen Carlo , Diederich François , Echegoyen Luis 
Published: October 2003

AbstractFour methanofullerene derivatives, with phosphonate or sulfone groups attached to a C60 core through a Bingel procedure, were synthesized to probe their stability upon electrolytic reduction. Derivatives 1 and 2 are the most stable upon electroreduction and do not exhibit retro‐cyclopropanation reactions until more than three electrons per C60 derivative are transferred. The cyclopropane ring is then removed and C60(>CH2)n (n=1–3) products result from reactions of the trianion of C60 with the solvent, CH2Cl2. The situation with diphosphonate 3 or phosphonatecarboxylate 4 is dramatically different. For 3, quantitative retro‐cyclopropanation occurs when 2.8 e− per molecule are transferred. In the case of 4, when more than two electrons per molecule are transferred, there is evidence of the reversible formation of a very stable intermediate, which is oxidized at a potential 500 mV more positive than the first fullerene‐based reduction of the parent compound. Electrolysis of a simple C70‐Bingel monoadduct (5) also exhibits the formation of a similar intermediate. On the basis of cyclic voltammetry, ESR spectroscopy, and MALDI analysis of products, the intermediate observed during the electrolysis of compounds 4 and 5 is assigned to a dimeric structure.
Absolute Asymmetric Synthesis of “Chiral‐at‐Metal” Grignard Reagents and Transfer of the Chirality to Carbon
Authors: Vestergren Marcus , Eriksson Johan , Håkansson Mikael 
Published: October 2003

AbstractTwo new six‐coordinate Grignard reagents, cis‐[(p‐CH3C6H4)MgBr(dme)2] (1) and cis‐[MgCH3(thf)(dme)2]I (2), have been synthesized and their crystal structures have been determined. Both reagents are cis‐octahedral and therefore chiral. They crystallize as conglomerates and racemize rapidly in solution. By utilizing these properties, the absolute asymmetric synthesis of specifically the Δ or the Λ enantiomer was achieved for both Grignard reagents. Enantiopure 1 and 2 were then reacted with butyraldehyde or benzaldehyde to give the corresponding alcohol in up to 22 % enantiomeric excess. At −60 °C, the Grignard reagents crystallize as racemic phases instead of conglomerates. Consequently, the crystal structures of rac‐cis‐[(p‐CH3C6H4)MgBr(dme)2]⋅DME (3) and rac‐cis‐[MgCH3(thf)(dme)2]I (4) could be determined.
Synthesis, Structure, and Spectroscopy of Phenylacetylenylene Rods Incorporating meso‐Substituted Dipyrrin Ligands
Authors: Halper Sara R. , Cohen Seth M. 
Published: October 2003

AbstractThe synthesis, structure, and spectroscopic characterization of a series of phenylacetylenylene rodlike molecules containing dipyrromethene (dipyrrin) ligands are described. The combination of the phenylacetylenylene groups with the porphyrinogenic dipyrrin moieties results in a rich absorption spectroscopy for these compounds, although the fluorescence of the phenylacetylenylene moiety is quenched by presence of the dipyrrin chelator. The Cu2+ and Fe3+ complexes of these ligands have been prepared and three of these compounds have been structurally characterized by using single‐crystal X‐ray diffraction. Unlike other octahedral metal‐dipyrrin complexes described to date, one of the iron complexes demonstrates ideal threefold symmetry in the solid‐state. The elongated structure and high symmetry of these complexes suggests the use of these meso‐substituted phenylacetylenylene ligands as an interesting class of extended, branched molecules for the construction of supramolecular architectures.
GA and AG Sequences of DNA React with Cisplatin at Comparable Rates
Authors: Monjardet‐Bas Véronique , Bombard Sophie , Chottard Jean‐Claude , Kozelka Jiří 
Published: October 2003

AbstractThe sequence selectivity of the antitumor drug cisplatin (cis‐[PtCl2(NH3)2] (1)) between the 5′‐AG‐3′ and 5′‐GA‐3′ sites of DNA has been a matter of discussion for more than twenty years. In this work, we compared the reactivity of GA and AG sequences of DNA towards the aquated forms of cisplatin (cis‐[PtCl(NH3)2(H2O)]+ (2), cis‐[Pt(NH3)2(H2O)2]2+ (3), and cis‐[Pt(OH)(NH3)2(H2O)]+ (4)) using two sets of experiments. In the first, we investigated a DNA hairpin, whose duplex stem contained a TGAT sequence as the single reactive site, and determined the individual rate constants of platination with 2 and 3 for G and A in acidic solution. The rate constants at 20 °C in 0.1 M NaClO4 at pH 4.5±0.1 were 0.09(4) M−1 s−1 (G) and 0.11(3) M−1 s−1 (A) for 2, and 9.6(1) M−1 s−1 (G) and 1.7(1) M−1 s−1 (A) for 3. These values are similar to those obtained previously for an analogous hairpin that contained a TAGT sequence. The monoadducts formed with 2 by both GA purines are extremely long‐lived, partly as a result of the slow hydrolysis of the chloro monoadduct at A, and partly because of the very low chelation rate (1.4×10−5 s−1 at 20 °C) of the aqua monoadduct on the guanine. In the second set of experiments, we incubated pure or enriched samples of 1, 2, 3, or 4 for 18–64 h at 25 °C with a 19 base pair (bp) DNA duplex, whose radiolabeled top strand contained one GA and one AG sequence as the only reactive sites. Quantification of the number of GA and AG cross‐links afforded a ratio of about two in favor of AG, irrespective of the nature of the leaving ligands. These results disagree with a previous NMR spectroscopy study, and indicate that GA sequences of DNA are substantially more susceptible to attack by cisplatin than previously thought.
α–γ Hybrid Peptides that Contain the Conformationally Constrained Gabapentin Residue: Characterization of Mimetics of Chain Reversals
Authors: Aravinda Subrayashastry , Ananda Kuppanna , Shamala Narayanaswamy , Balaram Padmanabhan 
Published: October 2003

AbstractThe crystal structures of four dipeptides that contain the stereochemically constrained γ‐amino acid residue gabapentin (1‐(aminomethyl)cyclohexaneacetic acid Gpn) are described. The molecular conformation of Piv‐Pro‐Gpn‐OH (1), reveals a β‐turn mimetic conformation, stabilized by a ten atom CH⋅⋅⋅O hydrogen bond between the Piv CO group and the pro S hydrogen of the Gpn CH2CO group. The peptides Boc‐Gly‐Gpn‐OH (2), Boc‐Aib‐Gpn‐OH (3), and Boc‐Aib‐Gpn‐OMe (4) form compact, folded structures, in which a distinct reversal of polypeptide chain direction is observed. In all cases, the Gpn residue adopts a gauche,gauche (g,g) conformation about the CγCβ (θ1) and CβCα (θ2) bonds. Two distinct Gpn conformational families are observed. In peptides 1 and 3, the average backbone torsion angle values for the Gpn residue are ϕ=98°, θ1=−62°, θ2=−73°, and ψ=79°, while in peptide 2 and 4 the average values are ϕ=−103°, θ1=−46°, θ2=−49°, and ψ=−92°. In the case of 1 and 3, an intramolecular nine‐membered OH⋅⋅⋅O hydrogen bond is formed between the CO of the preceding residue and the terminal carboxylic acid OH group. All four α–γ dipeptide sequences yield compact folded backbone conformations; this suggests that the Gpn residue may be employed successfully in the design of novel folded structures.
Discrete and Infinite Cage‐Like Frameworks with Inclusion of Anionic and Neutral Species and with Interpenetration Phenomena
Authors: Fan Jian , Zhu Hui‐Fang , Okamura Taka‐aki , Sun Wei‐Yin , Tang† Wen‐Xia , Ueyama Norikazu 
Published: October 2003

AbstractComplex [Ag(tpba)N3] (1) was obtained by reaction of novel tripodal ligand N,N′,N″‐tris(pyrid‐3‐ylmethyl)‐1,3,5‐benzenetricarboxamide (TPBA) with [Ag(NH3)2]N3. While the reactions between 1,3,5‐tris(imidazol‐1‐ylmethyl)‐2,4,6‐trimethylbenzene (TITMB) and silver(I) salts with different anions and solvent systems give six complexes: [Ag3(titmb)2](N3)3⋅CH3OH⋅4 H2O (2), [Ag3(titmb)2](CF3SO3)2(OH)⋅5 H2O (3), [Ag3(titmb)2][Ag(NO3)3]NO3⋅H2O (4), [Ag3(titmb)2(py)](NO3)3⋅H2O (py=pyridine) (5), [Ag3(titmb)2(py)](ClO4)3 (6), and [Ag3(titmb)2](ClO4)3⋅CHCl3 (7). The structures of these complexes were determined by X‐ray crystallography. The results of structural analysis of complexes 1 and 2, with the same azide anion but different ligands, revealed that 1 is a twofold interpenetrated 3D framework with interlocked cage‐like moieties, while 2 is a M3L2 type cage‐like complex with a methanol molecule inside the cage. Entirely different structure and topology between 1 and 2 indicates that the nature of organic ligands affected the structures of assemblies greatly. While in the cases of complexes 2–7 with flexible tripodal ligand TITMB, they are all discrete M3L2 type cages. The results indicate that the framework of these complexes is predominated by the nature of the organic ligand and geometric need of the metal ions, but not influenced greatly by the anions and solvents. It is interesting that there is a divalent anion [Ag(NO3)3]2− inside the cage 4 and an anion of ClO4− or NO3− spontaneously encapsulated within the cage of complexes 5, 6 and 7.
Wie entstand das Leben auf der Erde?: Ammoniak aus Stickstoff unter präbiotischen Bedingungen
Authors: Kreisel Günter , Wolf Claudia , Weigand Wolfgang , Dörr Mark 
Published: October 2003

AbstractDer Artikel befasst sich mit der Stickstoff‐Fixierung sowohl auf natürlichem, als auch auf technischem Wege. Zudem wird ein mögliches Szenario der Stickstoff‐Fixierung in präbiotischer Zeit vorgestellt. Das dabei entstehende Ammoniak ist Grundlage für die Bildung erster Aminosäuren, den Grundbausteinen aller stickstoffhaltigen Biomoleküle.
Stable Platinum(0) Catalysts for Catalytic Hydrosilylation of Styrene and Synthesis of [Pt(Ar‐bian)(η2‐alkene)] Complexes
Authors: Sprengers Jeroen W. , de Greef Michiel , Duin Marcel A. , Elsevier Cornelis J. 
Published: October 2003

AbstractThe use of alkenes and bidentate N‐ligands in the platinum(0)‐catalyzed hydrosilylation of styrene with triethylsilane has been evaluated. A number of bidentate N‐ligands, phen, bpy, dafo, and phenyl‐bian, were tested at various reaction temperatures using in situ formed catalysts with [Pt(nbe)3] as a precursor. The main conclusions are: (i) ligands, such as phen, which form stable platinum(0) complexes, give lower catalytic activities compared to the ligands which form less stable complexes; (ii) a small ligand effect is observed with dafo and phenyl‐bian compared to [Pt(nbe)3], the precursor complex, displaying the lability of these ligands. The complex [Pt(nbe)3], that only has labile alkene ligands, is an active catalyst at low temperatures. At higher temperatures, the catalyst is no longer stable and a decrease in yield is observed. Several novel complexes have been synthesized: [Pt(m,m‐(CF3)2‐C6H3‐bian)(tcne)], [Pt(m,m‐(CF3)2‐C6H3‐bian)(ma)], [Pt(p‐MeO‐C6H4‐bian)(ma)], [Pt(p‐MeO‐C6H4‐bian)(dmfu)] and [Pt(phenyl‐bian)(dmfu)]. Whereas the two [Pt(Ar‐bian)(ma)] complexes are intrinsically more active than the two [Pt(Ar‐bian)(dmfu)] complexes, the latter are much more stable, i.e. the nature of the alkene in these complexes is an important factor in determining their catalytic behavior. Compared to [Pt(Me‐nq)(nbe)2], the two [Pt(Ar‐bian)(dmfu)] complexes are much more stable resulting in significantly higher overall yields. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Long‐Lived MLCT Excited States‐RuII Complexes with a Helical Bis‐Phen Ligand
Authors: Goze Christine , Chambron Jean‐Claude , Heitz Valérie , Pomeranc Didier , Salom‐Roig Xavier J. , Sauvage Jean‐Pierre , Morales Angeles Farrán , Barigelletti Francesco 
Published: October 2003

AbstractThe synthesis of a new RuII complex [Ru(L1)(4,7‐dpphen)]2+, bearing a tetradentate bis‐1,10‐phenanthroline ligand L1, is described. X‐ray crystal structure analysis shows that the tetradentate ligand L1 coils around the metal and occupies both axial and two of the equatorial positions of the complex. 1H NMR studies clearly indicate that the complex has C2 symmetry in solution. The room temperature luminescence properties of [Ru(L1)(4,7‐dpphen)]2+ have been studied, as have those of the related complex [Ru(L2)(4,4′‐dmbp)]2+. For both complexes, the luminescence quantum yields and lifetimes are three to ten times higher than those of [Ru(bpy)3]2+. These unusual results are explained by the geometrical constraints imposed by the tetradentate ligands L1 and L2 in their respective complexes, resulting in an effective decoupling between the 3MLCT and 3MC excited states. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Coenzyme B12 Model Studies − Kinetics of Axial Ligation of Alkylcobalt Complexes Containing a Tridentate Amino‐Oximate Ligand
Authors: Alzoubi Basam M. , Hamza Mohamed S. A. , Felluga Alessandro , Randaccio Lucio , Tauzher Giovanni , van Eldik Rudi 
Published: October 2003

AbstractThe ligand‐substitution reaction of [RCo(LNHpy)(HLNHpy)]+ by cyanide was studied in methanol as a solvent, where R = Et (1), Me (2), CF3CH2 (3), and bridging CH2 (4), HLNHpy = 2‐(2‐pyridylethyl)amino‐3‐butanone oxime and LNHpy− is its conjugate base. The second‐order rate constants for the substitution of the 2‐pyridylethyl moiety in [RCo(LNHpy)(HLNHpy)]+ by cyanide were found to be 19.1, 0.25, 2.2·10−2, and 1.7·10−2 M−1·s−1 for R = Et, Me, CF3CH2, and bridging CH2, respectively. From the temperature‐ and pressure‐dependence studies of the substitution reaction, the activation parameters (ΔH‡, ΔS‡, ΔV‡) for the reaction of [RCo(LNHpy)(HLNHpy)]+ with cyanide in methanol were found to be, for R = Et: 69±2 kJ·mol−1, +11±7 J·K−1 mol−1, +9.6±0.3 cm3·mol−1; R = Me: 86±4 kJ·mol−1, +31±15 J·K−1·mol−1, +4.3±0.2 cm3·mol−1; R = CF3CH2: 73±3 kJ·mol−1, −33±10 J·K−1·mol−1, +8.7±0.2 cm3·mol−1; R = bridging CH2: 80±1 kJ·mol−1, −13±3 J·K−1·mol−1, +5.4±0.1 cm3·mol−1, respectively. Based on the reported rate and activation parameters, the mechanism of the ligand‐substitution reaction varies between a limiting dissociative and a dissociative interchange type of mechanism depending on the σ‐donor and steric effects of the alkyl group. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
P8O12·2BH3 − The Borane Adduct of a New Molecular Phosphorus Oxide
Authors: Tellenbach Akbar , Jansen Martin 
Published: October 2003

AbstractP4O6·BH3, which readily forms from P4O6 and Me2S·BH3 in a stoichiometric reaction, dimerizes spontaneously at −30 °C in a concentrated toluene solution resulting in the crystallization of P8O12·2BH3 (1). The synthesis of 1 represents the first selective interconnection of molecular phosphorus chalcogenides leading to the formation of a new, flexible P8O12 cage. The thermodynamic driving force for the dimerization reaction results from a gain of enthalpy due to enhanced P−O double‐bond contributions and a relief of angular strain. In terms of kinetics, the behavior of P4O6·BH3, differing from that of other P4O6 derivatives, is caused by the low π‐donor ability of BH3 provoking a Michaelis−Arbuzov‐like reactivity at the adjacent phosphorus atom and thus inducing cage opening. 1 was characterized by means of X‐ray diffractometry (powder, single crystal), NMR spectroscopy (solution, solid), IR spectroscopy, Raman spectroscopy, and mass spectrometry. Mass spectrometric investigations suggest considerable BH3 abstraction as well as an enhanced stability of P8O12·BH3 and P8O12, compared to 1. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis, Structure and Magnetic Properties of a New Iron Arsenate, [C10N4H28][{FeF(OH)(HAsO4)}4], with a Layer Structure
Authors: Chakrabarti Sandip , Pati Swapan K. , Green Mark A. , Natarajan Srinivasan 
Published: October 2003

AbstractThe reaction of FeCl3·6H2O, H3AsO4, HF and 1,4‐bis(3‐aminopropyl)piperazine under solvothermal conditions gives rise to a new iron arsenate, [C10N4H28][{FeF(OH)(HAsO4)}4] (I) with a layered structure. The cell parameters are monoclinic, space group = P21/n (no.14), M = 1143.08, a = 9.6320(3), b = 8.3598(3), c = 10.7794(1) Å, β = 115.036(1)°, V = 786.42(4) Å3, Z = 4, R1 = 0.0492, wR2 = 0.1227 [1114 observed reflections with I > 2σ(I)]. The connectivity between FeO3F2(OH) octahedra and HAsO4 tetrahedra forms a secondary building unit (SBU) of the type SBU‐4. The SBU‐4 units are linked together to form a layer structure with apertures formed by 8‐T atoms (T = Fe, As). The amine molecules are disordered and occupy the inter‐lamellar region. To the best of our knowledge, I is the first example of an iron arsenate structure formed from only one type of secondary building unit, SBU‐4. A dimer model has been used to describe the magnetic behavior. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Clinical application of the gender role strain paradigm: Group treatment for adolescent boys
Authors: Richmond Katherine , Levant Ronald 
Published: October 2003

AbstractThe aim of this article is to demonstrate the clinical application of the gender role strain paradigm with a group of adolescent boys. Adolescent boys experience overwhelming pressure to adhere to gender norms. As they attempt to conform to the expectations associated with the male role, boys suffer from gender role strain. We illustrate how the protective environment of the group enables boys to engage and discuss problems with male role norms. The shift in the boys' adherence to traditional notions of masculinity supports the utility of the gender role strain paradigm in clinical work. © 2003 Wiley Periodicals, Inc. J Clin Psychol/In Session.