bluuebunny/crossref_metadata_2025_split huggingface dataset:
Percutaneous coronary intervention with rotational atherectomy for severely calcified unprotected left main: Immediate and two‐years follow‐up results
Authors: Garcia‐Lara Juan , Pinar Eduardo , Valdesuso Raul , Lacunza Javier , Gimeno Juan R. , Hurtado José A. , Valdés‐Chávarri Mariano 
Published: November 2011

AbstractIntroduction: According to current practice guidelines, coronary bypass surgery is the standard care option for unprotected left main (ULM) stenosis. However, a group of high surgical risk patients who are not eligible for coronary bypass surgery could benefit from percutaneous coronary intervention (PCI). Severe calcification hampers PCI in this setting, and rotational atherectomy (RA) could be of great help. Methods: We retrospectively analyzed a cohort of 40 patients with severely calcified ULM stenosis, not eligible for coronary artery bypass grafting, who underwent RA in our center. Results: Forty patients (mean age, 73 ± 8 years; 26 males) with ULM stenosis were treated with RA. Twenty‐seven (67%) had distal stenosis. The mean number of treated vessels was 2.38 ± 0.74, with a mean lesion length of 30 ± 18 mm. Abciximab was used in 12 (30%) cases and an intra‐aortic balloon pump in three cases. One patient died during the procedure and another two patients died in the first 24 hr after the procedure. The major events registered after the procedure included one significant branch loss, and two minor and one major case of bleeding (the latter requiring transfusion) at the puncture point. After a median of 24.7 (IQR 19.6–34.3) months of follow‐up, 12 cardiac deaths were recorded. Survival free of cardiac death was 71 ± 7% and clinical guided target vessel revascularization 19.3 ± 7% at 2 years. Conclusion: In a group of high surgical risk patients, RA on severely calcified left main stenosis is feasible and, in spite of high mortality rates, could pose the only possible effective treatment. © 2012 Wiley Periodicals, Inc.
Iatrogenic perforation of the medial circumflex artery following femoral venous cannulation for transcatheter aortic valve replacement, presenting with retroperitoneal hematoma and successfully managed by percutaneous embolization and coiling
Authors: Shannon Joanne , Latib Azeem , Colombo Antonio 
Published: November 2011

AbstractVascular complications are a major concern during transcatheter aortic valve replacement and can occur independently of introducer size. Arterial and venous access must be meticulous to avoid potentially life‐threatening bleeding, which most commonly results from injury to the common femoral or iliac arteries. We report an unusual case of perforation of the medial circumflex branch of the common femoral artery resulting from attempted femoral venous cannulation. Injury to this vessel is characteristically associated with silent retroperitoneal extravasation and is notoriously difficult to recognize and treat. Despite identification of the perforation on contrast‐enhanced computed tomography, the anatomical site could only be localized to the medial circumflex branch on highly selective contrast angiography. Thereafter, it was successfully treated percutaneously by embolization and coiling. © 2012 Wiley Periodicals, Inc.
Nitrogen‐ and Oxygen‐Functionalized Multiwalled Carbon Nanotubes Used as Support in Iron‐Catalyzed, High‐Temperature Fischer–Tropsch Synthesis
Authors: Schulte Hendrik J. , Graf Barbara , Xia Wei , Muhler Martin 
Published: November 2011

AbstractHigh‐temperature Fischer–Tropsch synthesis for the production of short‐chain olefins over iron catalysts supported on multiwalled carbon nanotubes (CNTs) was investigated under industrially relevant conditions (340 °C, 25 bar, H2/CO=1) to elucidate the influence of nitrogen and oxygen functionalization of the CNTs on the activity, selectivity, and long‐term stability. Surface functionalization of the CNTs was achieved by means of a gas‐phase treatment using nitric acid vapor at 200 °C for oxygen functionalization (O‐CNTs) and ammonia at 400 °C for the subsequent nitrogen doping (N‐CNTs). Ammonium iron citrate impregnation followed by calcination was applied for the deposition of iron nanoparticles with particle sizes below 9 nm. Subsequent to reduction in pure H2 at 380 °C, the Fe/N‐CNT and Fe/O‐CNT catalysts were applied in Fischer–Tropsch synthesis, in which they showed comparable initial conversion values with an excellent olefin selectivity [S(C3–C6)>85 %] and low chain growth probability (α≤0.5). TEM analysis of the used catalysts detected particle sizes of 23 and 26 nm on O‐CNTs and N‐CNTs, respectively, and Fe5C2 was identified as the major phase by using XRD, with only traces of Fe3O4. After 50 h time on stream under steady‐state conditions, an almost twofold higher activity compared to the Fe/O‐CNT catalysts had been maintained by the Fe/N‐CNT catalysts, which are considered excellent Fischer–Tropsch catalysts for the production of short‐chain olefins owing to their high activity, high selectivity to olefins, low chain growth probability, and superior long‐term stability.
The Best of Two Worlds from the Gold Catalysis Universe: Making Homogeneous Heterogeneous
Authors: de Almeida Miguel Peixoto , Carabineiro Sónia A. C. 
Published: November 2011

AbstractHeterogeneous catalysts have well‐known advantages in the gas or liquid phase, which include facile separation, possibility of recycling, and potential application to continuous flow processes. Homogeneous catalysts have remarkable properties such as high activity, enantioselectivity, and well‐characterized structures. Heterogenization of metal complexes, through anchoring of inorganic/organometallic complexes on porous solid materials, is a way to combine the outstanding properties of both systems. This procedure has already been used with complexes of several metals such as chromium, cobalt, copper, manganese, molybdenum, nickel, or palladium, but heterogenization of gold complexes is still rare. Heterogeneous and homogeneous catalyses by gold have already established on their own, and the heterogenization of gold complexes is a very exciting and promising interface area of chemistry. This work reviews the attempts made so far by several authors on this important topic. The results obtained show that these hybrid materials can have improved activity and selectivity and are potential choice candidates for several catalytic processes.
Off‐Gases Optimization in a Hydrogen Network Refinery
Authors: Sardashti Birjandi M. R. , Shahraki F. 
Published: November 2011

AbstractFor optimization of a hydrogen network, a steam reformer is associated to the feedstock and linear programming (LP) is applied. The investigated network consists of one steam reformer and two feedstocks. By exerting LP and the mentioned association, total annual cost decreasing is achieved in a case study in which natural gas and off‐gas were considered as feedstocks. The optimization problems of the hydrogen network comprise the hydrogen network retrofit design and the feedstock selection with respect to their cost. Nonlinear programming (NLP) and mixed‐integer nonlinear programming (MINLP) models are developed for optimization based on a two‐case study: for the first one, an existent optimization method on hydrogen networks is investigated and for the second one, revision of a recent optimization method on hydrogen networks associated by an LP model in the steam reformer unit is applied. These two cases resulted in total annual cost reductions of 34 % and 45.9 %, respectively.
Equilibrium Lithium‐Ion Transport Between Nanocrystalline Lithium‐Inserted Anatase TiO2 and the Electrolyte
Authors: Ganapathy Swapna , van Eck Ernst R. H. , Kentgens Arno P. M. , Mulder Fokko M. , Wagemaker Marnix 
Published: November 2011

AbstractThe power density of lithium‐ion batteries requires the fast transfer of ions between the electrode and electrolyte. The achievable power density is directly related to the spontaneous equilibrium exchange of charged lithium ions across the electrolyte/electrode interface. Direct and unique characterization of this charge‐transfer process is very difficult if not impossible, and consequently little is known about the solid/liquid ion transfer in lithium‐ion‐battery materials. Herein we report the direct observation by solid‐state NMR spectroscopy of continuous lithium‐ion exchange between the promising nanosized anatase TiO2 electrode material and the electrolyte. Our results reveal that the energy barrier to charge transfer across the electrode/electrolyte interface is equal to or greater than the barrier to lithium‐ion diffusion through the solid anatase matrix. The composition of the electrolyte and in turn the solid/electrolyte interface (SEI) has a significant effect on the electrolyte/electrode lithium‐ion exchange; this suggests potential improvements in the power of batteries by optimizing the electrolyte composition.
Does a Concerted Non‐Insertive Mechanism Prevail over a σ‐Insertive Mechanism in Catalytic Cyclohydroamination by Magnesium Tris(oxazolinyl)phenylborate Compounds? A Computational Study
Authors: Tobisch Sven 
Published: November 2011

AbstractThe present study comprehensively explores alternative mechanistic pathways for intramolecular hydroamination of 2,2‐dimethyl‐4‐penten‐1‐amine (1) by [{ToM}MgMe] (ToM=tris(4,4‐dimethyl‐2‐oxazolinyl)phenylborate) (2) with the aid of density functional theory (DFT) calculations. A single‐step amidoalkene → cycloamine conversion through a concerted proton transfer associated with NC ring closure has been explored as one possible mechanism; its key features have been described. This non‐insertive pathway evolves via a six‐centre TS structure featuring activation of the olefin unit towards nucleophilic amido attack outside the immediate vicinity of the metal centre by amino proton delivery and describes a viable mechanistic variant for alkaline‐earth metal‐mediated aminoalkene hydroamination. However, herein is presented sound evidence for the operation of the MgN amido σ‐bond insertive mechanism, its turnover‐limiting activation barrier is found to be 5.0 kcal mol−1 lower than for the non‐insertive mechanism, for the cyclohydroamination of 2,2‐disubstituted 4‐aminoalkenes by a [{ToM}MgNHR] catalyst. The operative mechanism involves rapid equilibria of the {ToM}Mgamidoalkene resting state 3 with its amine adduct, easily accessible and thermodynamically disfavoured, hence reversible, 1,2‐olefin insertion into the MgN amido σ‐bond with ring closure at 3, linked to turnover‐limiting MgC azacycle tether aminolysis by an adduct substrate molecule, followed by facile cycloamine liberation to regenerate the active catalyst species 3. The following aspects are in support of this scenario: 1) the derived rate law is consistent with the experimentally obtained empirical rate law; 2) the reasonable agreement between the computationally estimated and the observed value of the primary KIE; 3) the assessed effective activation barrier for turnover‐limiting aminolysis matches empirically determined Eyring parameters remarkably well; and 4) the observed resistance of isolated 3 to undergo amidoalkene cycloamine/cycloamido transformation until further quantities of substrate is added is consistently explained. The herein unveiled insights into the structure–reactivity relationships will undoubtedly govern the rational design of alkaline‐earth metal‐based catalysts and likely facilitate further advances in the area.
Thymosin β4 induces folding of the developing optic tectum in the chicken (Gallus domesticus)
Authors: Wirsching Hans‐Georg , Kretz Oliver , Morosan‐Puopolo Gabriela , Chernogorova Petya , Theiss Carsten , Brand‐Saberi Beate 
Published: November 2011

AbstractThymosin β4 (Tβ4) is a highly conserved G‐actin binding polypeptide with multiple intra‐ and extracellular functions. While stem‐cell activation as well as promotion of cell survival and migration by Tβ4 have been investigated in various in vitro and in vivo studies, there are few data on the implications of Tβ4 in brain development. In the present study we analyzed Tβ4 expression in the developing optic tectum of the chicken (Gallus domesticus) and performed in ovo retroviral transduction and plasmid electroporation for overexpression and knockdown of Tβ4. We found marked Tβ4 expression in the tectal plate and in all neuronal layers of later developmental stages, but not in the ventricular zone where neural stem cells reside and divide. Knockdown of Tβ4 inhibited growth of Tβ4‐depleted hemispheres, whereas overexpression of Tβ4 led to the production of neuroepithelial folds resembling gyri and sulci, which are not normally present in avian brains. The mechanism yielding enhanced growth of Tβ4 overexpressing hemispheres involved enhanced proliferation, thus indicating an impact of Tβ4 on the neural stem cell and/or progenitor cell population. In summary, we found that due to its effects on proliferation, Tβ4 expression has a large impact on neuroepithelial and macroscopic brain development. J. Comp. Neurol. 520:1650–1662, 2012. © 2011 Wiley Periodicals, Inc.
Bral2 is indispensable for the proper localization of brevican and the structural integrity of the perineuronal net in the brainstem and cerebellum
Authors: Bekku Yoko , Saito Mai , Moser Markus , Fuchigami Maki , Maehara Ami , Nakayama Masaru , Kusachi Shozo , Ninomiya Yoshifumi , Oohashi Toshitaka 
Published: November 2011

AbstractPerineuronal nets (PNNs) are pericellular coats of condensed matrix that enwrap the cell bodies and dendrites of many adult central nervous system (CNS) neurons. These extracellular matrices (ECMs) play a structural role as well as instructive roles in the control of CNS plasticity and the termination of critical periods. The cartilage link protein Crtl1/Hapln1 was reported to be a trigger for the formation of PNNs in the visual cortex. Bral2/Hapln4 is another link protein that is expressed in PNNs, mainly in the brainstem and cerebellum. To assess the role of Bral2 in PNN formation, we examined the expression of PNN components in targeted mouse mutants lacking Bral2. We show here that Bral2‐deficient mice have attenuated PNNs, but the overall levels of chondroitin sulfate proteoglycans, lecticans, are unchanged with the exception of neurocan. Bral2 deficiency markedly affected the localization of brevican in all of the nuclei tested, and neurocan concomitant with Crtl1 in some of the nuclei, whereas no effect was seen on aggrecan even with the attenuation of Crtl1. Bral2 may have a role in the organization of the PNN, in association with brevican, that is independent of aggrecan binding. There was a heterogenous attenuation of PNN components, including glycosaminoglycans, indicating the elaborate molecular organization of the PNN components. Strikingly, a slight decrease in the number of synapses in deep cerebellar nuclei neurons was found. Taken together, these results imply that Bral2‐brevican interaction may play a key role in synaptic stabilization and the structural integrity of the PNN. J. Comp. Neurol. 520:1721–1736, 2012. © 2011 Wiley Periodicals, Inc.
Failure of lower motor neuron radial outgrowth precedes retrograde degeneration in a feline model of spinal muscular atrophy
Authors: Wakeling Erin N. , Joussemet Béatrice , Costiou Patrick , Fanuel Dominique , Moullier Philippe , Barkats Martine , Fyfe John C. 
Published: November 2011

AbstractFeline spinal muscular atrophy (SMA) is a fully penetrant, autosomal recessive lower motor neuron disease in domestic cats that clinically resembles human SMA Type III. A whole genome linkage scan identified a ∼140‐kb deletion that abrogates expression of LIX1, a novel SMA candidate gene of unknown function. To characterize the progression of feline SMA, we assessed pathological changes in muscle and spinal cord from 3 days of age to beyond onset of clinical signs. Electromyographic (EMG) analysis indicating denervation occurred between 10 and 12 weeks, with the first neurological signs occurring at the same time. Compound motor action potential (CMAP) amplitudes were significantly reduced in the soleus and extensor carpi radialis muscles at 8–11 weeks. Quadriceps femoris muscle fibers from affected cats appeared smaller at 10 weeks; by 12 weeks atrophic fibers were more prevalent than in age‐matched controls. In affected cats, significant loss of L5 ventral root axons was observed at 12 weeks. By 21 weeks of age, affected cats had 40% fewer L5 motor axons than normal. There was no significant difference in total L5 soma number, even at 21 weeks; thus degeneration begins distal to the cell body and proceeds retrogradely. Morphometric analysis of L5 ventral roots and horns revealed that 4 weeks prior to axon loss, motor axons in affected cats failed to undergo radial enlargement, suggesting a role for the putative disease gene LIX1 in radial growth of axons. J. Comp. Neurol. 520:1737–1750, 2012. © 2011 Wiley Periodicals, Inc.
Synuclein accumulation is associated with cell‐specific neuronal death after spinal cord injury
Authors: Busch David J. , Morgan Jennifer R. 
Published: November 2011

AbstractSpinal cord injury axotomizes neurons and induces many of them to die, whereas others survive. Therefore, it is important to identify factors that lead to neuronal death after injury as a first step toward developing better strategies for increasing neuronal survival and functional recovery. However, the intrinsic molecular pathways that govern whether an injured neuron lives or dies remain surprisingly unclear. To address this question, we took advantage of the large size of giant reticulospinal (RS) neurons in the brain of the lamprey, Petromyzon marinus. We report that axotomy of giant RS neurons induces a select subset of them to accumulate high levels of synuclein, a synaptic vesicle‐associated protein whose abnormal accumulation is linked to Parkinson's disease. Injury‐induced synuclein accumulation occurred only in neurons that were classified as “poor survivors” by both histological and Fluoro‐Jade C staining. In contrast, post‐injury synuclein immunofluorescence remained at control levels in neurons that were identified as “good survivors.” Synuclein accumulation appeared in the form of aggregated intracellular inclusions. Cells that accumulated synuclein also exhibited more ubiquitin‐containing inclusions, similar to what occurs during disease states. When synuclein levels and cell vitality were measured in the same neurons, it became clear that synuclein accumulation preceded and strongly correlated with subsequent neuronal death. Thus, synuclein accumulation is identified as a marker and potential risk factor for forthcoming neuronal death after axotomy, expanding its implications beyond the neurodegenerative diseases. J. Comp. Neurol. 520:1751–1771, 2012. © 2011 Wiley Periodicals, Inc.
Using text mining to link journal articles to neuroanatomical databases
Authors: French Leon , Pavlidis Paul 
Published: November 2011

AbstractThe electronic linking of neuroscience information, including data embedded in the primary literature, would permit powerful queries and analyses driven by structured databases. This task would be facilitated by automated procedures that can identify biological concepts in journals. Here we apply an approach for automatically mapping formal identifiers of neuroanatomical regions to text found in journal abstracts, applying it to a large body of abstracts from the Journal of Comparative Neurology (JCN). The analyses yield over 100,000 brain region mentions, which we map to 8,225 brain region concepts in multiple organisms. Based on the analysis of a manually annotated corpus, we estimate mentions are mapped at 95% precision and 63% recall. Our results provide insights into the patterns of publication on brain regions and species of study in JCN but also point to important challenges in the standardization of neuroanatomical nomenclatures. We find that many terms in the formal terminologies never appear in a JCN abstract, and, conversely, many terms that authors use are not reflected in the terminologies. To improve the terminologies, we deposited 136 unrecognized brain regions into the Neuroscience Lexicon (NeuroLex). The training data, terminologies, normalizations, evaluations, and annotated journal abstracts are freely available at http://www.chibi.ubc.ca/WhiteText/. J. Comp. Neurol. 520:1772–1783, 2012. © 2011 Wiley Periodicals, Inc.
Renewable Rigid Diamines: Efficient, Stereospecific Synthesis of High Purity Isohexide Diamines
Authors: Thiyagarajan Shanmugam , Gootjes Linda , Vogelzang Willem , van Haveren Jacco , Lutz Martin , van Es Daan S. 
Published: November 2011

AbstractWe report an efficient three‐step strategy for synthesizing rigid, chiral isohexide diamines derived from 1,4:3,6‐dianhydrohexitols. These biobased chiral building blocks are presently the subject of several investigations (in our and several other groups) because of their application in high‐performance biobased polymers, such as polyamides and polyurethanes. Among the three possible stereo‐isomers, dideoxy‐diamino isoidide and dideoxy‐diamino isosorbide can be synthesized from isomannide and isosorbide respectively in high yield with absolute stereo control. Furthermore, by using this methodology dideoxy‐amino isomannide—a tricyclic adduct—was obtained starting from isoidide in high yield. Our improved synthetic route is a valuable advance towards meeting scale and purity demands for evaluating the properties of new biobased performance materials, which will benefit the development of these plastics.
Intense harvesting of eastern wolves facilitated hybridization with coyotes
Authors: Rutledge Linda Y. , White Bradley N. , Row Jeffrey R. , Patterson Brent R. 
Published: November 2011

AbstractDespite ethical arguments against lethal control of wildlife populations, culling is routinely used for the management of predators, invasive or pest species, and infectious diseases. Here, we demonstrate that culling of wildlife can have unforeseen impacts that can be detrimental to future conservation efforts. Specifically, we analyzed genetic data from eastern wolves (Canis lycaon) sampled in Algonquin Provincial Park (APP), Ontario, Canada from 1964 to 2007. Research culls in 1964 and 1965 killed the majority of wolves within a study region of APP, accounting for approximately 36% of the park's wolf population at a time when coyotes were colonizing the region. The culls were followed by a significant decrease in an eastern wolf mitochondrial DNA (mtDNA) haplotype (C1) in the Park's wolf population, as well as an increase in coyote mitochondrial and nuclear DNA. The introgression of nuclear DNA from coyotes, however, appears to have been curtailed by legislation that extended wolf protection outside park boundaries in 2001, although eastern wolf mtDNA haplotype C1 continued to decline and is now rare within the park population. We conclude that the wolf culls transformed the genetic composition of this unique eastern wolf population by facilitating coyote introgression. These results demonstrate that intense localized harvest of a seemingly abundant species can lead to unexpected hybridization events that encumber future conservation efforts. Ultimately, researchers need to contemplate not only the ethics of research methods, but also that future implications may be obscured by gaps in our current scientific understanding.