bluuebunny/crossref_metadata_2025_split huggingface dataset:
Documentation and three‐dimensional modelling of human soleus muscle architecture
Authors: Agur Anne M. , Ng‐Thow‐Hing Victor , Ball Kevin A. , Fiume Eugene , McKee Nancy Hunt 
Published: June 2003

AbstractThe purpose of this study was to visualize and document the architecture of the human soleus muscle throughout its entire volume. The architecture was visualized by creating a three‐dimensional (3D) manipulatable computer model of an entire cadaveric soleus, in situ, using B‐spline solid to display muscle fiber bundles that had been serially dissected, pinned, and digitized. A database of fiber bundle length and angle of pennation throughout the marginal, posterior, and anterior soleus was compiled. The computer model allowed documentation of the architectural parameters in 3D space, with the angle of pennation being measured relative to the tangent plane of the point of attachment of a fiber bundle. Before this study, the only architectural parameters that have been recorded have been 2D. Three‐dimensional reconstruction is an exciting innovation because it makes feasible the creation of an architectural database and allows visualization of each fiber bundle in situ from any perspective. It was concluded that the architecture is non‐uniform throughout the volume of soleus. Detailed architectural studies may lead to the development of muscle models that can more accurately predict interaction between muscle parts, force generation, and the effect of pathologic states on muscle function. Clin. Anat. 16:285–293, 2003. © 2003 Wiley‐Liss, Inc.
Left musculus sternalis
Authors: Arráez‐Aybar L.A. , Sobrado‐Perez J. , Merida‐Velasco J.R. 
Published: June 2003

AbstractDuring routine dissection in the Morphological Sciences Department II of the Universidad Complutense de Madrid, the presence of a sternalis muscle was observed in the left hemithorax of a 70‐year‐old male cadaver. We report on its position, relationships, and innervation, as well as its clinical relevance, indicating some guidelines for its physical examination. We also present a brief overview of the existing literature regarding the nomenclature, historical reports, and incidence of this muscle. Clin. Anat. 16:350–354, 2003. © 2003 Wiley‐Liss, Inc.
Pivotal role of the sub‐supracardinal anastomosis in the development and course of the left renal vein
Authors: Macchi V. , Parenti A. , De Caro R. 
Published: June 2003

AbstractA retroaortic left renal vein is encountered frequently in the dissecting room and in radiological investigations. A number of recent reports of this variation led us to review the development of the renal veins and the inferior vena cava to understand its etiology. For further insight, we also examined our collection of serial sections of cat embryos. In human embryos of about 15 mm the “renal collar,” a venous ring around the aorta, is formed by anastomoses between subcardinal and supracardinal veins. The ventral part of the “renal collar” is formed from the intersubcardinal anastomosis, the dorsal part from the intersupracardinal anastomosis and the lateral parts from the sub‐supracardinal anastomoses. The primitive renal veins drain venous blood from the metanephros into the sub‐supracardinal anastomoses. A retroaortic left renal vein would form if the dorsal part of the sub‐supracardinal anastomosis and the intersupracardinal anastomosis persist whereas the ventral part of the sub‐supracardinal anastomosis and the intersubcardinal anastomosis regress. Clin. Anat. 16:358–361, 2003. © 2003 Wiley‐Liss, Inc.
Selective Rearrangements of Quadruply Hydrogen‐Bonded Dimer Driven by Donor–Acceptor Interaction
Authors: Wang Xiao‐Zhong , Li Xiao‐Qiang , Shao Xue‐Bin , Zhao Xin , Deng Peng , Jiang Xi‐Kui , Li Zhan‐Ting , Chen Ying‐Qi 
Published: June 2003

AbstractA general method has been developed to control the selective rearrangement of Meijer's AADD quadruply hydrogen‐bonded homodimers by introducing an additional donor–acceptor interaction. Therefore, one donor‐assembling monomer, 1, in which the electron‐rich bis(p‐phenylene)‐34‐crown‐10 moiety is connected to the hydrogen‐bonding moiety, and two acceptor‐assembling monomers, 2 and 3, in which the electron‐deficient pyromellitic diimide or naphthalene diimide group is incorporated, respectively, are synthesized and characterized. 1H NMR and 2D‐NOESY studies show that all these compounds exist as stable homodimers in chloroform. Mixing 1 equiv of 1 with 1 equiv of 2 in chloroform leads to the formation of heterodimers 1⋅2 in ≈60 % yield, as a result of the electrostatic interaction between the bis(p‐phenylene)‐34‐crown‐10 moiety of 1 and the pyromellitic diimide group of 2. Selective formation of heterodimer 1⋅3 (>97 %) was achieved by mixing 1 equiv of 1 with 1 equiv of 3 in chloroform which resulted in a strengthened electrostatic interaction between the bis(p‐phenylene)‐[34]crown‐10 moiety of 1 and the naphthalene diimide group of 3. The structures of heterodimers 1⋅2 and 1⋅3, which have been characterized by 1H NMR and UV/Vis experiments, reveal a remarkable promoting effect between the donor–acceptor interaction and intermolecular hydrogen‐bonding. 1H NMR studies also reveal that heterodimers 1⋅2 and 1⋅3 can be fully and partially dissociated by addition of heterocycle 29, leading to the formation of new more robust heterodimers 1⋅29 and 2⋅29, or 3⋅29,respectively, and partially regenerated by subsequent addition of heterocyclic compound 30 through the formation of a new heterodimer 29⋅30. Heterodimers 1⋅2 and 1⋅3 represent a novel class of pseudo[2]rotaxanes constructed by two different noncovalent interactions.
Theoretical Studies on the Metathesis Processes, [Tp(PH3)MR(η2‐HCH3)] → [Tp(PH3)M(CH3)(η2‐HR)] (M=Fe, Ru, and Os; R=H and CH3)
Authors: Lam Wai Han , Jia Guochen , Lin Zhenyang , Lau Chak Po , Eisenstein Odile 
Published: June 2003

AbstractTheoretical calculations on the metathesis process, [Tp(PH3)MR(η2‐HCH3)] → [Tp(PH3)M(CH3)(η2‐HR)] (M=Fe, Ru, and Os; R=H and CH3), have been systematically carried out to study their detailed reaction mechanisms. Other than the one‐step mechanism via a four‐center transition state and the two‐step mechanism through an oxidative addition/reductive elimination pathway, a new one‐step mechanism, with a transition state formed under oxidative addition, has been found. Based on the intrinsic reaction coordinate calculations, we found that the trajectories of the transferring hydrogen atom in the metathesis processes studied are similar to each other regardless of the nature of reaction mechanisms.
Synthesis of Directly Linked Zinc(II) Porphyrin–Imide Dyads and Energy Gap Dependence of Intramolecular Electron Transfer Reactions
Authors: Yoshida Naoya , Ishizuka Tomoya , Yofu Katsuyuki , Murakami Masataka , Miyasaka Hiroshi , Okada Tadashi , Nagata Yasushi , Itaya Akira , Cho Hyun Sun , Kim Dongho , Osuka Atsuhiro 
Published: June 2003

AbstractA series of zinc(II) porphyrin–imide dyads (ZP‐Im), in which an electron donating ZP moiety is directly connected to an electron accepting imide moiety in the meso position, have been prepared for the examination of energy gap dependence of intramolecular electron transfer reactions with large electronic coupling. The nearly perpendicular conformation of the imide moiety towards the porphyrin plane has been revealed by Xray crystal structures. The energy gap for charge separation, 1ZP*–Im→ZP+–Im−, is varied by changing the electron accepting imide moiety to cover a range of about 0.8 eV in DMF. Definitive evidence for electron transfer has been obtained in three solvents (toluene, THF, and DMF) through picosecond–femtosecond transient absorption studies, which have allowed us to determine the rates of photoinduced charge separation, 1ZP*–Im→ZP+–Im−, and subsequent thermal charge recombination ZP+–Im−→ZP–Im. The free‐energy gap dependence (energy gap law) has been probed from the normal to the nearly top region for the charge separation rate alone, and only the inverted region for the charge recombination rate. Although both of the energy gap dependencies can be approximately reproduced by means of the simplified semiclassical equation, when we take into consideration the effect of the high frequency vibrations replaced by one mode of averaged frequency, many features, including the effects of solvent polarity and the electron tunneling matrix element on the energy gap law, differ considerably from those of the previously studied porphyrin–quinone systems, which have weaker interchromophore electronic interactions.
3[(d, dxy)(pz)] Excited States of Binuclear Copper(I) Phosphine Complexes: Effect of Copper–Ligand and Copper–Copper Interactions on Excited State Properties and Photocatalytic Reductions of the 4,4′‐Dimethyl‐2,2′‐bipyridinium Ion in Alcohols.
Authors: Mao Zhong , Chao Hsiu‐Yi , Hui Zheng , Che Chi‐Ming , Fu Wen‐Fu , Cheung Kung‐Kai , Zhu Nianyong 
Published: June 2003

AbstractA comprehensive study of the structural and spectroscopic properties of two‐, three‐, and four‐coordinate copper(i) complexes with aliphatic phosphine ligands is presented. All complexes described in this work are characterized by Xray crystallography. The intramolecular Cu⋅⋅⋅Cu separations in [Cu2(dcpm)2]X2, [Cu2(dcpm)2(CH3CN)2]X2, and [Cu2(dmpm)3](ClO4)2 (dcpm=bis(dicyclohexylphosphino)methane; dmpm=bis(dimethylphosphino)methane; X=ClO4− and PF6−) are in the range 2.639(2)–3.021(2) Å. The anion⋅⋅⋅CuI interaction is weak, as evidenced by the nearest O⋅⋅⋅Cu separation of 2.558(6) Å in [Cu2(dcpm)2](ClO4)2 and the closest Cu⋅⋅⋅F separation of 2.79(1) Å in [Cu2(dcpm)2](PF6)2. The absorption bands of [Cu2(dcpm)2]X2 and [Cu2(dcpm)2(CH3CN)2]X2 (X=ClO4− and PF6−) at λmax 307–311 nm in CH2Cl2 are assigned as 1[3dσ* → 4pσ] transitions; this has been confirmed by resonance Raman spectroscopy. The triplet emissions in the visible region from these complexes exhibit long lifetimes and are sensitive to the environment. The lowest emissive excited state is tentatively ascribed as 3[(d, dxy)(pz)] in nature. For [Cu2(dcpm)2]2+ salts in CH3CN, the emissive species is postulated to be [Cu2(dcpm)2(CH3CN)n]2+ (n≥3). Efficient photocatalytic reduction of MV2+ (4,4′‐dimethyl‐2,2′‐bipyridinium) to MV+ in alcoholic solutions by using [Cu2(dcpm)2](PF6)2 or [Cu2(dppm)2(CH3CN)4](ClO4)2 (dppm=bis(diphenylphosphino)methane) as a catalyst has been observed. The addition of CH3CN or use of [Cu2(dmpm)3](ClO4)2 as a catalyst did not allow photocatalytic reduction processes to occur.
Dynamic Covalent Approach to [2]‐ and [3]Rotaxanes by Utilizing a Reversible Thiol–Disulfide Interchange Reaction
Authors: Furusho Yoshio , Oku Tomoya , Hasegawa Toshihide , Tsuboi Akiyoshi , Kihara Nobuhiro , Takata Toshikazu 
Published: June 2003

AbstractA dynamic covalent approach to disulfide‐containing [2]‐ and [3]rotaxanes is described. Symmetrical dumbbell‐shaped compounds with two secondary ammonium centers and a central located disulfide bond were synthesized as components of rotaxanes. The rotaxanes were synthesized from the dumbbell‐shaped compounds and dibenzo‐[24]crown‐8 (DB24C8) with catalysis by benzenethiol. The yields of isolated rotaxanes reached about 90 % under optimized conditions. A kinetic study on the reaction forming [2]rotaxane 2 a and [3]rotaxane 3 a suggested a plausible reaction mechanism comprising several steps, including 1) initiation, 2) [2]rotaxane formation, and 3) [3]rotaxane formation. The whole reaction was found to be reversible in the presence of thiols, and thermodynamic control over product distribution was thus possible by varying the temperature, solvent, initial ratio of substrates, and concentration. The steric bulk of the end‐capping groups had almost no influence on rotaxane yields, but the structure of the thiol was crucial for reaction rates. Amines and phosphines were also effective as catalysts. The structural characterization of the rotaxanes included an Xray crystallographic study on [3]rotaxane 3 a.
Photochemical and Thermal Isomerization Processes of a Chiral Auxiliary Based Donor–Acceptor Substituted Chiroptical Molecular Switch: Convergent Synthesis, Improved Resolution and Switching Properties
Authors: van Delden Richard A. , Hurenkamp Johannes H. , Feringa Ben L. 
Published: June 2003

AbstractA new type of chiroptical molecular switch is presented where irradiation employing different wavelengths of light induces a reversible helix inversion of a sterically overcrowded alkene bearing a second chiral entity in the form of a stereogenic center present in a pyrrolidine unit. The additional stereogenic center in the chiral auxiliary group has a distinct influence on the switching selectivity of this system and greatly facilitates the resolution of the different diastereoisomers, which is a considerable improvement compared with previously reported systems. In addition, the pyrrolidine stereogenic center causes small energetic differences between the various states of the switch system resulting in a small but significant directional preference in the helix inversion steps.
Arylazide Cycloaddition to Methyl Propiolate: DFT‐Based Quantitative Prediction of Regioselectivity
Authors: Molteni Giorgio , Ponti Alessandro 
Published: June 2003

AbstractSeveral 1(4‐substituted)phenyl‐4‐ or 5methoxycarbonyl‐1,2,3‐triazoles have been synthesized by 1,3‐dipolar cycloaddition of the corresponding arylazides to methyl propiolate in carbon tetrachloride. The regioselectivity of these reactions cannot be rationalized on the basis of the electronic demands of the reactants or frontier molecular‐orbital theory. Therefore, we applied to this problem a quantitative formulation of the HSAB principle to this problem developed within density functional theory. Global and local reactivity indices were computed at B3LYP/6‐311+G(d,p) level both in vacuo and in carbon tetrachloride (by the COSMO approach). The direction of charge transfer upon reactive encounter has been determined and the computed regioselectivity has been shown to be in good agreement with the experimental results. The relationship between computed and experimental data and how it is affected by the solvent have been discussed.
Synthesis and Nonlinear Optical Properties of Fluorine‐Containing Naphthalocyanines
Authors: Yang Guo Ying , Hanack Michael , Lee Yiew Wang , Chen Yu , Lee May Ka Yuen , Dini Danilo 
Published: June 2003

AbstractThe fluorine‐containing metal naphthalocyanines [F16NcGaCl] (7) and [(F16NcGa)2O] (8), which represent the first examples of peripherally fluorine substituted naphthalocyanines, were synthesized, and the nonlinear optical transmission was studied. Peripheral substitution by fluorine atoms enhances the solubility and photostability of the naphthalocyanines. In particular, for the axially μ‐oxo‐bridged naphthalocyanine dimer 8, practically no aggregation was observed in organic solvents and it has proved to be an efficient optical limiter when irradiated with laser light pulses at the wavelength of 532 nm, with pulse duration of 5 ns and repetition rate of 20 Hz.
The Synthesis of Carboracycles Derived from B,B′‐Bis(aryl) Derivatives of Icosahedral ortho‐Carborane
Authors: Bayer Michael J. , Herzog Axel , Diaz Martin , Harakas George A. , Lee Hans , Knobler Carolyn B. , Hawthorne M. Frederick 
Published: June 2003

AbstractReactions of both closo‐9,12‐I2‐1,2‐C2B10H10 and closo‐9,10‐I2‐1,7‐C2B10H10 with an excess of aryl magnesium bromide in the presence of [PdCl2(PPh3)2] afford the corresponding closo‐9,12‐(4‐R‐C6H4)2‐1,2‐C2B10H10 [R=H (1), Me (2), OMe (3), SMe (4), N(CH3)2 (5), Cl (6)] and closo‐9,10‐(4‐R′‐C6H4)2‐1,7‐C2B10H10 [R′=Me (7), OMe (8), N(CH3)2 (9), Cl (10), and ‐C[(OCH2)2]CH3 (11)] compounds in high yields. The anisole derivatives 3 and 8 were deprotected to yield the corresponding bis‐phenols 12 and 13, respectively. Structural analyses of compounds 1, 3, 6, and 12 are reported. Re‐etherification of compound 12 by using γ‐bromotriethyleneglycol methyl ether provided 14 (R=(CH2CH2O)3CH3). Oxidation of 4 with ceric(IV) ammonium nitrate (CAN) generated the bis‐sulfoxide 15 (R=S(O)Me). Deprotection of compound 11 led to the corresponding acetyl derivative 18 (R′=C(O)Me). Bis‐anisole 3 was tethered with 1,3‐dibromopropane, 1,6‐dibromohexane, 1,8‐dibromooctane, 4,4′‐bis(iodomethyl)‐1,1′‐biphenyl, and α,α′‐dibromo‐2,6‐lutidine to afford the dimers 20 b, 21 b, 22 b, 23 b, and 24 b, respectively. The tetrameric carboracycles 27 a and 30 a, as well as the dimeric 29 c were obtained through repetitive coupling of the dimeric compounds 20 b, 24 b, and 22 b with 1,3‐dibromopropane, α,α′‐dibromo‐2,6‐lutidine, and 1,8‐dibromooctane, respectively. The tetrameric carboracycle 28 a was obtained upon consecutive reactions of 1 with 1,4‐dibromobutane. Hexameric carboracycle 28 b was identified as a byproduct. Exhaustive ether cleavage of 27 a generated octaphenol 31 a. Re‐etherification of 31 a with trimethylenesultone provided the octasulfonate 32 a, the first example of a water‐soluble carboracycle. Linkage of dimer 23 b with α,α′‐dibromolutidine yielded the cyclic tetrameric tetrapyridyl derivative 30 a in low yield. The structures of the carboracycles 27 a, 28 a, 28 b, and 30 a have been confirmed by Xray crystallography. In addition, the compounds 28 a,b are the first reported carboracycles that interact with solvent molecules in a host–guest fashion.
Upon the Intriguing Stereoselective Formation of Organobismuth(V) Complexes
Authors: Barucki Hubert , Coles Simon J. , Costello James F. , Hursthouse Michael B. 
Published: June 2003

AbstractThe preparation of triphenylbismuth(V) 3 a–k and antimony(V) 4 e–k bis‐carboxy ester complexes is described. A range of studies in solution suggest that the diastereoselective formation of (RR,SS)‐3 a–j is governed by the thermodynamic stability of rapidly interconverting epimeric species. Diastereoselectivity is absent in the case of the corresponding Sb complexes, leading to the conclusion that a combination of both ligand–ligand (steric) and metal–ligand (hyperconjugative) interactions govern stereoselectivity. The formation of homochiral complexes (RR,SS)‐3 a–j is rationalised using a simple model, invoking for the first time a palindromic BiPh3 propeller moiety, which correlates the chirality of the trans axial carboxy‐ester ligands. The Xray crystal structures of both hetero‐ and homochiral diastereoisomeric antimony complexes (4 h and 4 i, respectively) are presented in support of this model.
Differential distribution of calbindin D28k and parvalbumin among functionally distinctive sets of structures in the macaque brainstem
Authors: Parvizi Josef , Damasio Antonio R. 
Published: June 2003

AbstractIn a study of brainstem in the cynomolgus monkey, we found that the distribution of calbindin D28K (CB) and parvalbumin (PV) is nonoverlapping among functionally distinct sets of brainstem structures. Nuclei involved in representation and regulation of the organism's internal state contain CB, whereas those involved in the representation of the external environment and the representation or execution of externally directed actions contain only PV. Moreover, our findings indicate that different nuclei known as components of the ascending reticular activating system (ARAS) contain either CB or PV or both, suggesting that this system in primates operates with both CB and PV. In line with previously reported findings, we also found that unmyelinated pathways contain only CB, whereas myelinated pathways contain PV. Distribution of CB and PV in the macaque brainstem follows a pattern comparable to, but in some instances significantly different than, the pattern previously reported in the rat. We argue that the nonoverlapping distribution of CB and PV among different structures of the brainstem might reflect underlying differences in the physiological, anatomic, and perhaps phylogenetic properties of these structures. Considering our recent findings of selective vulnerability of brainstem structures to Alzheimer's disease, the present data suggest that the majority of macaque brainstem nuclei that contain CB are vulnerable to neurofibrillary tangles in humans. By contrast, only few nuclei that contain PV exhibit pathologic changes. Some of these nuclei are affected with a high number of neuritic plaques without ever developing neurofibrillary tangles. J. Comp. Neurol. 462:153–167, 2003. © 2003 Wiley‐Liss, Inc.
Parasol cells of the hemiellipsoid body in the crayfish Procambarus clarkii: Dendritic branching patterns and functional implications
Authors: McKinzie Mary Elizabeth , Benton Jeanne L. , Beltz Barbara S. , Mellon DeForest 
Published: June 2003

AbstractMultimodal, higher‐order sensory integration in decapod crustaceans occurs in local interneurons (parasol cells) within a structure in the lateral protocerebrum, the hemiellipsoid body, which is located dorsal to the terminal medulla. The hemiellipsoid body is targeted by projection neuron inputs by means of the olfactory globular tract from bilateral deutocerebral neuropils, the accessory lobes, which receive secondary visual, mechanosensory, and olfactory inputs. Parasol cell dendrites arborize extensively within the two neuropils of the hemiellipsoid body and possibly have some neurites within another neuropil at its base. The two neuropils of the hemiellipsoid body, neuropils I and II, are known to receive asymmetrical inputs from the contralateral and ipsilateral accessory lobes, and our current study addresses the question of the distribution of parasol cells within these two neuropils. Three anatomic methods were used to analyze this distribution: intracellular filling of cells with neurobiotin and visualization of the cells by using either a fluorescent or a peroxidase avidin conjugate, or placement of a fluorescent lipophilic tracer within a lobe of the hemiellipsoid body. All of these methods demonstrated that single parasol cells exclusively arborize within one of the two lobes of the hemiellipsoid body, but not in both lobes. Electrophysiological recordings from pairs of parasol cells with dendrites in the same or different lobes confirm a functional separation between neuropils I and II. Comparisons are made between insect and crustacean systems, emphasizing the inputs to the hemiellipsoid body and the mushroom body and similarities between extrinsic cells in insects and parasol cells in decapod crustaceans. J. Comp. Neurol. 462:168–179, 2003. © 2003 Wiley‐Liss, Inc.