bluuebunny/crossref_metadata_2025_split huggingface dataset:
Endovascular treatment of traumatic rupture of the thoracic aorta
Authors: Lettinga-van de Poll T , Schurink G W H , De Haan M W , Verbruggen J P A M , Jacobs M J 
Published: April 2007

AbstractBackgroundTraumatic rupture of the thoracic aorta is a life-threatening event. Open surgical repair is the ‘gold standard’, but is associated with high mortality and morbidity rates. Endovascular repair is emerging as a potentially safer alternative.MethodsA systematic review was performed of all published literature on this subject, including the authors' own experience. Using Sumsearch, PubMed and cross-references, all published reports up to January 2006 were identified, and analysed for injuries, perioperative morbidity, mortality, operating time, hospital stay and follow-up.ResultsA total of 284 patients were identified. Reported mortality rates range from 0 to 6 per cent. The procedure-related mortality rate is about 1·5 per cent. Some 6·7 per cent of all procedures were complicated by endoleak and the overall procedure-related morbidity rate was 14·4 per cent. These results are promising compared with those of open repair, but individual experience is limited and there may be some publication bias.ConclusionEndovascular repair of traumatic rupture of the thoracic aorta seems to reduce morbidity and mortality in patients with multiple trauma. Ideally, both devices and experienced personnel should be available in trauma centres.
Parallel strategies of occlusion culling on cluster of GPUs
Authors: Xiong Hua , Peng Haoyu , Qin Aihong , Shi Jiaoying 
Published: April 2007

AbstractParallel rendering, visibility culling and level‐of‐detail are key techniques to improve the rendering performance for large geometric data sets. Although each of these techniques has been researched extensively and some systems have been developed to combine them together. However, parallel occlusion culling, that is distributing the computation of occlusion culling to multiple computing nodes such as a CPUs cluster or a GPUs cluster, has rarely been touched. This is because most existing occlusion culling algorithms are difficult to parallelize or do not scale well when parallelized. We first introduce a novel occlusion culling algorithm that uses the occlusion query functionality provided by current GPU. We employ a visibility prediction technique based on temporal coherence to reduce the times of occlusion query. Furthermore, different strategies of parallelizing the occlusion culling algorithm on a GPUs cluster are proposed including data parallelism strategies and functionality parallelism strategies. Data parallelism strategies decompose the data sets for occlusion query into disjoint parts and map these queries on different cluster nodes for parallel execution while functionality parallelism strategies assemble an occlusion culling pipeline with multiple cluster nodes which outputs image stream steadily. We propose a number of solutions to some special issues on parallelizing this occlusion culling algorithm, such as the transferring of data dependency and the load‐balancing of occlusion culling pipeline. Experimental results demonstrate the efficiency of the proposed parallelism strategies of the occlusion culling algorithm based on the visibility predictor. Copyright © 2007 John Wiley & Sons, Ltd.
Interactive soft‐touch dynamic deformations
Authors: Chen Hui , Sun Hanqiu , Jin Xiaogang 
Published: April 2007

AbstractIt is crucial for the users to touch, grasp and manipulate the interested objects through our sense of touch in many interactive applications, such as on‐line computer games, interactive cartoon design, and virtual prototyping. In this paper, we propose an interactive haptic deformation approach which incorporates the dynamic simulation of mass–spring systems and flexible control of free‐form deformation in the touch‐enabled soft‐object deformation. Through distributing mass, spring and damping coefficients of the object to the bounded Bezier volume lattice, the deformation of the object related to the haptic avatar follows the physical laws and has high working rate. Both homogenous and inhomogenous materials are simulated. The anchor nodes of haptic input are specified to create amazing special effects during the interactive haptic deformation. Interactive haptic deformations of three‐type tropic fishes, Angel, Demekin, and GuppyBlueGrass, have been experimented to simulate vivid fish swimming processes in the virtual ocean scene. Our proposed approach provides touch‐enabled input and efficient performance in the flexible deforming controls, letting the objects move in a dynamic, cartoon‐style deforming manner. Copyright © 2007 John Wiley & Sons, Ltd.
On a Hypothetical Generational Relationship between HCN and Constituents of the Reductive Citric Acid Cycle
Authors: Eschenmoser Albert 
Published: April 2007

AbstractEncouraged by observations made on the course of reactions the HCN‐tetramer can undergo with acetaldehyde, I delineate a constitutional and potentially generational relationship between HCN and those constituents of the reductive citric acid cycle that are direct precursors of amino acids in contemporary metabolism. In this context, the robustness postulate of classical prebiotic chemistry is questioned, and, by an analysis of the (hypothetical) reaction‐tree of a stepwise hydrolysis of the HCN‐tetramer, it is shown how such a non‐robust chemical reaction platform could harbor the potential for the emergence of autocatalytic cycles. It is concluded that the chemistry of HCN should be revisited by focussing on its non‐robust parts in order to demonstrate its full potential as one of the possible roots of prebiotic self‐organizing chemical processes.
On the Chemistry and Evolution of the Pioneer Organism
Authors: Wächtershäuser Günter 
Published: April 2007

AbstractThe theory of a chemo‐autotrophic origin of life in a volcanic Iron‐Sulfur World postulates the emergence of a pioneer organism within a flow of volcanic exhalations. The pioneer organism is characterized by a composite structure with an inorganic substructure and an organic superstructure. Within the surfaces of the inorganic substructure, iron, cobalt, nickel, and other transition‐metal centers with sulfido, carbonyl, cyano, and other ligands are catalytically active, and promote the growth of the organic superstructure through carbon fixation, driven by the reducing potential of the volcanic exhalations. This pioneer organism is reproductive by an autocatalytic feedback effect, whereby some organic products serve as ligands for activating the catalytic metal centres whence they arise. This unitary structure–function relationship of the pioneer organism constitutes the ‘Anlage’ for two major strands of evolution: enzymatization and cellularization, whereby the upward evolution of life by increase of molecular complexity is grounded ultimately in the transition metal‐catalyzed, synthetic redox chemistry of the pioneer organism.
Errors and Alternatives in Prebiotic Replication and Catalysis
Authors: Ninio Jacques 
Published: April 2007

AbstractThe work on nonenzymatic nucleic acid replication performed by Leslie Orgel and co‐workers over the last four decades, now extended by work on artificial selection of RNA aptamers and ribozymes, is generating some pessimism concerning the ‘naked gene’ theories of the origin of life. It is suggested here that the low probability of finding RNA aptamers and ribozymes within pools of random sequences is not as disquieting as the poor gain in efficiency obtained with increases in information content. As acknowledged by Orgel and many other authors, primitive RNA replication and catalysis must have occurred within already complex and dynamic environments. I, thus, propose to pay attention to a number of possibilities that bridge the gap between ‘naked gene’ theories, on one side, and metabolic theories in which complex systems self‐propagate by growth and fragmentation, on the other side. For instance, one can de‐emphasize nucleotide‐by‐nucleotide replication leading to long informational polymers, and view instead long random polymers as storage devices, from which shorter oligomers are excised. Catalytic tasks would be mainly performed by complexes associating two or more oligomers belonging to the same or to different chemical families. It is proposed that the problems of stability, binding affinity, reactivity, and specificity could be easier to handle by heterogeneous complexes of short oligomers than by long, single‐stranded polymers. Finally, I point out that replication errors in a primitive replication context should include incorporations of alternative nucleotides with interesting, chemically reactive groups. In this way, an RNA sequence could be at the same time an inert sequence when copied without error, and a ribozyme, when a chemically reactive nucleotide is inadvertently introduced during replication.
Nonenzymatic Recombination of RNA: Possible Mechanism for the Formation of Novel Sequences
Authors: Lutay Alexei V. , Zenkova Marina A. , Vlassov Valentin V. 
Published: April 2007

AbstractWe report on the formation of novel RNA molecules in a recombination‐like, nonenzymatic reaction proceeding in the complex of partially complementary RNA‐oligonucleotides under very simple conditions. Analysis of the isolated products demonstrated that at least 5% of the formed linkages are of the (natural) 3′,5′‐phosphodiester type. We suggest that similar reactions could contribute to the development of the ‘RNA world’, but could also proceed in vivo within variously structured RNA or RNA complexes containing loops, bulges, or dangling ends, providing an emergence of novel RNA sequences.
Chemical Primer Extension: Individual Steps of Spontaneous Replication
Authors: Stütz Jan A. Rojas , Kervio Eric , Deck Christopher , Richert Clemens 
Published: April 2007

AbstractThe replication of genetic information, as we know it from today's biology, relies on template‐directed, polymerase‐catalyzed extension of primers. It is known that short stretches of complementary RNA can form on templates in the absence of enzymes. This account summarizes recent work on efficient enzyme‐free primer extension, both with 3′‐amino‐terminal deoxyribonucleotide primers and with primers made of unmodified RNA. Near‐quantitative primer extension with half‐life times on the order of hours has been demonstrated by using azaoxybenzotriazolides of nucleotides and downstream‐binding oligomers. Further, small non‐nucleosidic substituents placed on the terminus of the template or the downstream‐binding oligomer have been shown to increase the rate and fidelity of primer‐extension reactions. Since all four templating bases (A, C, G, T/U) direct sequence‐selective primer‐extension steps, we feel that there is renewed hope that full, nonenzymatic replication from monomers may eventually be achieved.
On the Interactions of Alkyl 2‐Hydroxycarboxylic Acids with Alkoxysilanes: Selective Esterification of Simple 2‐Hydroxycarboxylic Acids
Authors: Ansell Richard J. , Barrett Simon A. , Meegan Jonathan E. , Warriner Stuart L. 
Published: April 2007

AbstractThe interactions of a range of monocarboxylic acids with tetramethoxysilane Si(OMe)4 (TMOS), in methanol (MeOH), have been investigated by using 1H, 13C and 29Si solution‐phase NMR spectroscopy and electrospray mass spectrometry (ESMS). Si(OMe)4 acts as a catalyst/reagent in the selective methylation of 2‐hydroxycarboxylic acids (2HOAs) in MeOH at room temperature: glycolic acid, lactic acid and 2‐hydroxybutyric acid are esterified more than a hundred times faster in MeOH and Si(OMe)4 than in MeOH alone. No acceleration of methylation is observed for carboxylic acids lacking the 2‐hydroxy group. Methylation of the 2HOAs is associated with the condensation of individual siloxane units to form oligomers. A mechanism is proposed in which 2HOAs attach to silicon via the alkoxy group, then subsequently via the carboxyl group in an intramolecular rearrangement to form an unstable and reactive cyclic intermediate. This intermediate may lead to accelerated methylation of the carboxylic acid via nucleophilic attack of MeOH at the carbonyl group, while a separate reaction pathway leads to condensation of silanols and/or alkoxysilanes leading to oligosiloxanes. The mechanism has implications for the use of 2HOAs as templates in sol–gel silica preparation.
The Ball‐Shaped Heteropolytungstates [{Sn(CH3)2(H2O)}24{Sn(CH3)2}12(A‐XW9O34)12]36− (X=P, As): Stability, Redox and Electrocatalytic Properties in Aqueous Media
Authors: Keita Bineta , de Oliveira Pedro , Nadjo Louis , Kortz Ulrich 
Published: April 2007

AbstractThe electrochemical behavior of the ball‐shaped heteropolytungstates [{Sn(CH3)2(H2O)}24{Sn(CH3)2}12(A‐XW9O34)12]36− (X=P, 1; As, 2) was examined in aqueous electrolytes by redissolution of their respective mixed cesium–sodium salts Cs14Na22[{Sn(CH3)2(H2O)}24{Sn(CH3)2}12 (A‐PW9O34)12]⋅149 H2O (Cs14‐1) and Cs14Na22[{Sn(CH3)2(H2O)}24{Sn(CH3)2}12(A‐AsW9O34)12]⋅149 H2O (Cs14‐2). In the studied media, Cs14‐2 is readily soluble in contrast to the significantly less soluble Cs14‐1. The solubility of Cs14‐1 is increased by the presence of Li+ ions in solution. Gel filtration studies with 1 and 2 rule out a decay of the dodecameric spherical assemblies to Keggin‐based monomers on the timescale of the experiment. By UV/Vis spectroscopy and cyclic voltammetry, 2 was found to be significantly less stable than 1 and both polyanions also show rather different decomposition pathways. Polyanion 1 collapses first into Keggin‐type monomers which might contain the trilacunary [A‐α‐PW9O34]9−. The final monomeric species obtained from 1 appears to be very similar to [PW11O39]7−, which is the final transformation product of [A‐α‐PW9O34]9− in the same media. In contrast, 2 does not seem to follow an analogous transformation pathway as that of the trilacunary [A‐α‐AsW9O34]9−. Importantly, stabilization of 1 is observed in chloride media. The fairly long‐term stability of 1 in 1 M LiCl, pH 3, has allowed for its electrochemical study to be carried out. The solid‐state cyclic voltammogram of 1 entrapped in a carbon paste electrode shows the same characteristics as 1 dissolved in chloride solutions, thus supporting the conclusion that the polyanion is stable in these environments. Controlled potential coulometry on 1 indicates that the number of electrons consumed in the first wave is larger than twenty. To our knowledge, 1 constitutes the first example of a molecule that can take up such a large number of electrons resulting in a chemically reversible W‐wave. These properties show promise for future fundamental and applied studies. Polyanion 1 is also efficient in the electrocatalytic reduction of NOx, including nitrate. Finally, a remarkable interaction was found between 1 and NO, a highly promising feature for biomimetic applications.
Multisensory convergence in auditory cortex, I. Cortical connections of the caudal superior temporal plane in macaque monkeys
Authors: Smiley John F. , Hackett Troy A. , Ulbert Istvan , Karmas George , Lakatos Peter , Javitt Daniel C. , Schroeder Charles E. 
Published: April 2007

AbstractThe caudal medial auditory area (CM) has anatomical and physiological features consistent with its role as a first‐stage (or “belt”) auditory association cortex. It is also a site of multisensory convergence, with robust somatosensory and auditory responses. In this study, we investigated the cerebral cortical sources of somatosensory and auditory inputs to CM by injecting retrograde tracers in macaque monkeys. A companion paper describes the thalamic connections of CM (Hackett et al., J. Comp. Neurol. [this issue]). The likely cortical sources of somatosensory input to CM were the adjacent retroinsular cortex (area Ri) and granular insula (Ig). In addition, CM had reliable connections with areas Tpt and TPO, which are sites of multisensory integration. CM also had topographic connections with other auditory areas. As expected, connections with adjacent caudal auditory areas were stronger than connections with rostral areas. Surprisingly, the connections with the core were concentrated along its medial side, suggesting that there may be a medial‐lateral division of function within the core. Additional injections into caudal lateral auditory area (CL) and Tpt showed similar connections with Ri, Ig, and TPO. In contrast to CM injections, these lateral injections had inputs from parietal area 7a and had a preferential connection with the lateral (gyral) part of Tpt. Taken together, the findings indicate that CM may receive somatosensory input from nearby areas along the fundus of the lateral sulcus. The differential connections of CM compared with adjacent areas provide additional evidence for the functional specialization of the individual auditory belt areas. J. Comp. Neurol. 502:894–923, 2007. © 2007 Wiley‐Liss, Inc.
Topographic organization of sensory afferents of Johnston's organ in the honeybee brain
Authors: Ai Hiroyuki , Nishino Hiroshi , Itoh Tsunao 
Published: April 2007

AbstractJohnston's organ (JO) in insects is a multicellular mechanosensory organ stimulated by movement of the distal part of the antenna. In honeybees JO is thought to be a primary sensor detecting air‐particle movements caused by the waggling dance of conspecifics. In this study projection patterns of JO afferents within the brain were investigated. About 720 somata, distributed around the periphery of the second segment of the antenna (pedicel), were divided into three subgroups based on their soma location: an anterior group, a ventral group, and a dorsal group. These groups sent axons to different branches (N2 to N4) diverged from the antennal nerve. Dye injection into individual nerve branches revealed that all three groups of afferents, having fine collaterals in the dorsal lobe, sent axons broadly through tracts T6I, T6II, and T6III to terminate ipsilaterally in the medial posterior protocerebral lobe, the dorsal region of the subesophageal ganglion, and the central posterior protocerebral lobe, respectively. Within these termination fields only axon terminals running in T6I were characterized by thick processes with large varicosities. Differential staining using fluorescent dyes revealed that the axon terminals of the three groups were spatially segregated, especially in T6I, showing some degree of somatotopy. This spatial segregation was not observed in axon terminals running in other tracts. Our results show that projection patterns of JO afferents in the honeybee brain fundamentally resemble those in the dipteran brain. The possible roles of extensive termination fields of JO afferents in parallel processings of mechanosensory signals are discussed. J. Comp. Neurol. 502:1030–1046, 2007. © 2007 Wiley‐Liss, Inc.
Distribution of Kv3.3 potassium channel subunits in distinct neuronal populations of mouse brain
Authors: Chang Su Ying , Zagha Edward , Kwon Elaine S. , Ozaita Andres , Bobik Marketta , Martone Maryann E. , Ellisman Mark H. , Heintz Nathaniel , Rudy Bernardo 
Published: April 2007

AbstractKv3.3 proteins are pore‐forming subunits of voltage‐dependent potassium channels, and mutations in the gene encoding for Kv3.3 have recently been linked to human disease, spinocerebellar ataxia 13, with cerebellar and extracerebellar symptoms. To understand better the functions of Kv3.3 subunits in brain, we developed highly specific antibodies to Kv3.3 and analyzed immunoreactivity throughout mouse brain. We found that Kv3.3 subunits are widely expressed, present in important forebrain structures but particularly prominent in brainstem and cerebellum. In forebrain and midbrain, Kv3.3 expression was often found colocalized with parvalbumin and other Kv3 subunits in inhibitory neurons. In brainstem, Kv3.3 was strongly expressed in auditory and other sensory nuclei. In cerebellar cortex, Kv3.3 expression was found in Purkinje and granule cells. Kv3.3 proteins were observed in axons, terminals, somas, and, unlike other Kv3 proteins, also in distal dendrites, although precise subcellular localization depended on cell type. For example, hippocampal dentate granule cells expressed Kv3.3 subunits specifically in their mossy fiber axons, whereas Purkinje cells of the cerebellar cortex strongly expressed Kv3.3 subunits in axons, somas, and proximal and distal, but not second‐ and third‐order, dendrites. Expression in Purkinje cell dendrites was confirmed by immunoelectron microscopy. Kv3 channels have been demonstrated to rapidly repolarize action potentials and support high‐frequency firing in various neuronal populations. In this study, we identified additional populations and subcellular compartments that are likely to sustain high‐frequency firing because of the expression of Kv3.3 and other Kv3 subunits. J. Comp. Neurol. 502:953–972, 2007. © 2007 Wiley‐Liss, Inc.
Anterior hypothalamic neural activation and neurochemical associations with aggression in pair‐bonded male prairie voles
Authors: Gobrogge Kyle L. , Liu Yan , Jia Xixi , Wang Zuoxin 
Published: April 2007

AbstractMale prairie voles (Microtus ochrogaster) display mating‐induced pair bonding indicated by social affiliation with their female partners and aggression toward unfamiliar conspecifics. In the present study, we characterized their aggression associated with pair bonding and examined the related neuronal activation and neurochemical architecture. Males that were pair‐bonded for 2 weeks displayed intense levels of aggression toward a female or male conspecific stranger but maintained a high level of social affiliation with their familiar female partners. These social interactions induced increases in neural activation, indicated by increased density of Fos‐immunoreactive staining (Fos‐ir) in several brain regions including the bed nucleus of the stria terminalis (BNST), medial preoptic area (MPOA), paraventricular nucleus (PVN), anterior cortical (AcA), and medial nuclei (MeA) of the amygdala. In the anterior hypothalamus (AH), increased density of Fos‐ir staining was found specifically to be associated with aggression toward unfamiliar female or male strangers. In addition, higher densities of AH cells that were stained for tyrosine hydroxylase (TH) or vasopressin (AVP) were also labeled with Fos‐ir in these males displaying aggression toward a conspecific stranger compared with males displaying social affiliation toward their female partner. Together, our results indicate that dopamine and vasopressin in the AH may be involved in the regulation of enduring aggression associated with pair bonding in male prairie voles. J. Comp. Neurol. 502:1109–1122, 2007. © 2007 Wiley‐Liss, Inc.
Molecular heterogeneity of developing retinal ganglion and amacrine cells revealed through single cell gene expression profiling
Authors: Trimarchi Jeffrey M. , Stadler Michael B. , Roska Botond , Billings Nathan , Sun Ben , Bartch Brandon , Cepko Constance L. 
Published: April 2007

AbstractDuring development of the central nervous system (CNS), cycling uncommitted progenitor cells give rise to a variety of distinct neuronal and glial cell types. As these different cell types are born they progress from newly specified cells to fully differentiated neurons and glia. In order to define the developmental processes of individual cell types, single cell expression profiling was carried out on developing ganglion and amacrine cells of the murine retina. Individual cells from multiple developmental stages were isolated and profiled on Affymetrix oligonucleotide arrays. Two‐color fluorescent in situ hybridization on dissociated retinas was used to verify and extend the microarray results by allowing quantitative measurements of a large number of cells coexpressing two genes. Together, these experiments have yielded an expanded view of the processes underway in developing retinal ganglion and amacrine cells, as well as several hundred new marker genes for these cell types. In addition, this study has allowed for the definition of some of the molecular heterogeneity both between developing ganglion and amacrine cells and among subclasses of each cell type. J. Comp. Neurol. 502:1047–1065, 2007. © 2007 Wiley‐Liss, Inc.