bluuebunny/crossref_metadata_2025_split huggingface dataset:
Control of the Coordination Geometry Around Platinum by a Supramolecular Capsule
Authors: Koblenz Tehila S. , Dekker Henk L. , de Koster Chris G. , van Leeuwen Piet W. N. M. , Reek Joost N. H. 
Published: September 2011

AbstractThe coordination geometry around a platinum atom can be controlled by a diphosphane capsule composed of a tetracationic xantphos‐type ligand and a tetraanionic calix[4]arene. Reaction of the diphosphane capsule with the platinum precursor [PtCl2(MeCN)2] yields the bisligated biscalix[4]arene trans‐platinum capsule, whereas the same diphosphane in the absence of calix[4]arene prefers the formation of the monoligated cis‐platinum complex, as indicated by 31P{1H} NMR and ESI‐MS. The two calix[4]arenes stabilize the kinetic product (trans‐Pt), and slow the formation of the thermodynamic product (cis‐Pt).
Integrated platform of capillary isoelectric focusing, trypsin immobilized enzyme microreactor and nanoreversed‐phase liquid chromatography with mass spectrometry for online protein profiling
Authors: Wang Tingting , Ma Junfeng , Wu Shuaibin , Yuan Huiming , Zhang Lihua , Liang Zhen , Zhang Yukui 
Published: September 2011

AbstractAn integrated platform with the combination of protein and peptide separation was established via online protein digestion, by which proteins were first separated by CIEF, online digested by a trypsin immobilized enzyme microreactor, trapped and desalted by two parallel trap columns, separated by nanoreversed‐phase and finally identified by MS. In such a platform, two hollow fiber membrane interfaces were used. One was applied to supply catholyte and electric contact, and another to supply adjustment buffer to improve the compatibility of protein separation and tryptic digestion. A poly(octadecyl acrylate‐co‐ethylene dimethacrylate) monolithic column served as the trap column to capture sample and to remove the ampholytes from CIEF. A hybrid silica monolith‐based immobilized trypsin microreactor was used for online protein digestion. To evaluate the performance of such a platform, a 4‐protein mixture with a loading amount of only 0.29 μg, was analyzed, and sequence coverages for BSA, myoglobin, β‐lactoglobulin and ribonuclease A were 8, 26, 10 and 54%, respectively. Furthermore, such an integrated platform was successfully applied for the analysis of proteins extracted from Escherichia coli, and 101 proteins were positively identified. We anticipate that the integrated platform developed herein will provide a promising tool for low‐abundance protein identification with the combination of top‐down and bottom‐up approaches.
Fast analysis of amino acids in wine by capillary electrophoresis with laser‐induced fluorescence detection
Authors: Mandrioli Roberto , Morganti Emanuele , Mercolini Laura , Kenndler Ernst , Raggi Maria A. 
Published: September 2011

AbstractA fast analytical method has been developed for the determination of nine amino acids, together with serotonin, in wine samples of different origin and vintage. The method is based on capillary electrophoresis coupled to laser‐induced fluorescence detection. Separation was obtained by using a fused‐silica capillary (75 μm id, 74.0 cm total length, 60.0 cm length to detector) and a background electrolyte composed of carbonate buffer (20 mM, pH 9.2), applying a 20 kV voltage. Direct hydrodynamic injection of wine samples was made after an original microwave‐assisted derivatisation step with 5‐(4,6‐dichlorotriazinyl)aminofluorescein. Fluorescence was induced by an Ar‐Ion laser, exciting at 488 nm. Good linearity (r2>0.9990) was obtained for all considered analytes and sensitivity was also good, with limits of detection in the 7–50 ng/mL range. The method was successfully applied for the analysis of commercial Italian wines and thus seems to be suitable for the determination of the relevant amino acids and serotonin, providing good results in terms of accuracy and precision, together with the advantage of a very fast, microwave‐assisted derivatisation procedure. Future applications of the method are planned to check for wine adulterations and commercial frauds.
High‐speed separation of proteins by sodium dodecyl sulfate‐capillary gel electrophoresis with partial translational spontaneous sample injection
Authors: Lin Qing‐Hu , Cheng Yong‐Qiang , Dong Ya‐Ni , Zhu Ying , Pan Jian‐Zhang , Fang Qun 
Published: September 2011

AbstractIn this study, we developed a picoliter‐scale partial translational spontaneous injection approach which is suitable for high‐speed protein separation under sodium dodecyl sulfate‐capillary gel electrophoresis mode. On the basis of this approach, we built a high‐speed CE system for protein separation based on a short capillary and slotted‐vial array. The system has the advantages of simple structure, ease of building without the requirement of microfabricated devices, convenient operation, and low cost. Under the optimized conditions, picoliter‐scale sample plugs (corresponding to ∼65 μm plug length) were obtained, which ensured both the high speed and the high efficiency in protein separation. Five fluorescein isothiocyanate labeled proteins including myoglobin, egg albumin, bovine serum albumin, phosphorylase b, and myosin were separated within 60 s with an effective separation length of 1.5 cm. Theoretical plates per meter ranging from 2.58×105 to 1.28×106 (corresponding to 0.78–3.88 μm plate height) were obtained. The separation speed and separation efficiency of the present system are comparable to those of most microchip‐based capillary electrophoresis systems for protein separation. The relative standard deviations of the migration times were in the range of 0.9–1.3% (n=5). Good linear relationships between log relative molecular mass and migration time were obtained in the molecular weigh range of 17 200–500 000, which demonstrate the present system can be applied in protein relative molecular mass determination.
Seeing with the eyes shut: Neural basis of enhanced imagery following ayahuasca ingestion
Authors: de Araujo Draulio B. , Ribeiro Sidarta , Cecchi Guillermo A. , Carvalho Fabiana M. , Sanchez Tiago A. , Pinto Joel P. , de Martinis Bruno S. , Crippa Jose A. , Hallak Jaime E.C. , Santos Antonio C. 
Published: September 2011

AbstractThe hallucinogenic brew Ayahuasca, a rich source of serotonergic agonists and reuptake inhibitors, has been used for ages by Amazonian populations during religious ceremonies. Among all perceptual changes induced by Ayahuasca, the most remarkable are vivid “seeings.” During such seeings, users report potent imagery. Using functional magnetic resonance imaging during a closed‐eyes imagery task, we found that Ayahuasca produces a robust increase in the activation of several occipital, temporal, and frontal areas. In the primary visual area, the effect was comparable in magnitude to the activation levels of natural image with the eyes open. Importantly, this effect was specifically correlated with the occurrence of individual perceptual changes measured by psychiatric scales. The activity of cortical areas BA30 and BA37, known to be involved with episodic memory and the processing of contextual associations, was also potentiated by Ayahuasca intake during imagery. Finally, we detected a positive modulation by Ayahuasca of BA 10, a frontal area involved with intentional prospective imagination, working memory and the processing of information from internal sources. Therefore, our results indicate that Ayahuasca seeings stem from the activation of an extensive network generally involved with vision, memory, and intention. By boosting the intensity of recalled images to the same level of natural image, Ayahuasca lends a status of reality to inner experiences. It is therefore understandable why Ayahuasca was culturally selected over many centuries by rain forest shamans to facilitate mystical revelations of visual nature. Hum Brain Mapp, 2012. © 2011 Wiley Periodicals, Inc.
NOS1 ex1f‐VNTR polymorphism affects prefrontal oxygenation during response inhibition tasks
Authors: Kopf Juliane , Schecklmann Martin , Hahn Tim , Dieler Alica C. , Herrmann Martin J. , Fallgatter Andreas J. , Reif Andreas 
Published: September 2011

AbstractImpulsivity is a trait shared by many psychiatric disorders and therefore a suitable intermediate phenotype for their underlying biological mechanisms. One of the molecular determinants involved is the NOS1 ex1f‐VNTR, whose short variants are associated with a variety of impulsive behaviors. Fifty‐six healthy controls were stratified into homozygous long (LL) (30 probands) and short (SS) (26 probands) allele groups. Subjects completed a combined stop‐signal go/nogo task, while the oxygenation in the prefrontal cortex was measured with functional near‐infrared spectroscopy. Electromyography was recorded to control for differences in muscle activity in the two inhibition tasks. Two questionnaires on impulsive traits were completed. Differences between the two tasks are shown by distinct activation patterns within the prefrontal cortex. The nogo task resulted mainly in the activation of the dorsolateral prefrontal cortex (dlPFC), whereas successful and unsuccessful inhibition in the stop‐signal task elicited the predicted activity in the inferior frontal cortex (IFC). Although significant differences were found in neither the scores obtained on impulsivity‐related questionnaires nor the behavioral data, the LL group displayed increased dlPFC activity during nogo trials and the predicted activation in the IFC during successful inhibition in the stop‐signal task, while no significant activation was found in the SS group. Our data confirm an influence of NOS1 ex1f‐VNTR on impulsivity, as carriers of the short risk allele exhibited diminished activity of (pre‐)frontal brain regions during the inhibition in a stop‐signal task. Impairment of prefrontal control with consecutive failure of inhibitory processes might underlie association findings reported previously. Hum Brain Mapp, 2012. © 2011 Wiley Periodicals, Inc.
N‐phosphinyl ureas: Synthesis, characterization, X‐ray structure, and in vitro evaluation of antitumor activity
Authors: Gholivand Khodayar , Dorosti Nilufar , Ghaziany Fatemeh , Mirshahi Manouchehr , Sarikhani Sina 
Published: September 2011

AbstractA new series of N‐phosphinylureas 5b, 6a–7c was synthesized and characterized by 1H, 13C, 31P NMR, IR, and elemental analysis. The three‐dimensional structure of 5b has been determined by X‐ray crystallography. The crystal structure revealed the existence of four independent molecules. All structures form two chains with different arrangements and connect to each other via hydrogen bonds to produce two‐dimensional polymeric chains. The cytotoxicity of cyclophosphamide (a standard antitumor compound) and its nine analogues with formula R1C6H4 NHC(O)NHP(O)XCH2C(R2)2 CH2Y(X = Y = NH, R2 = CH3, R1 = H (5a), CH3 (5b), NO2 (5c), X = O, Y = NH, R2 = H, R1 = H (6a, CH3 (6b), NO2 (6c), and X = Y = O, R2 = CH3, R1 = H (7a), CH3 (7b), NO2 (7c)) as well as phenyl urea were evaluated in vitro against three human tumor cell lines K562, MDA‐MB‐231, and HepG2. The results showed that most of the compounds have significant activity against the selected cell lines. Also, HepG2 cells were more sensitive to all the tested compounds than other cell lines. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 23:74–83, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.20754
Gerechte designs with rectangular regions
Authors: Courtiel J. , Vaughan E. R. 
Published: September 2011

AbstractA gerechte framework is a partition of an n × n array into n regions of n cells each. A realization of a gerechte framework is a latin square of order n with the property that when its cells are partitioned by the framework, each region contains exactly one copy of each symbol. A gerechte design is a gerechte framework together with a realization.We investigate gerechte frameworks where each region is a rectangle. It seems plausible that all such frameworks have realizations, and we present some progress toward answering this question. In particular, we show that for all positive integers s and t, any gerechte framework where each region is either an s × t rectangle or a t × s rectangle is realizable. © 2011 Wiley Periodicals, Inc. J Combin Designs 20:112‐123, 2012
Spanning Cycles Through Specified Edges in Bipartite Graphs
Authors: Zamani Reza , West Douglas B. 
Published: September 2011

AbstractPósa proved that if G is an n‐vertex graph in which any two nonadjacent vertices have degree‐sum at least n + k, then G has a spanning cycle containing any specified family of disjoint paths with a total of k edges. We consider the analogous problem for a bipartite graph G with n vertices and parts of equal size. Let F be a subgraph of G whose components are nontrivial paths. Let k be the number of edges in F, and let t1 and t2 be the numbers of components of F having odd and even length, respectively. We prove that G has a spanning cycle containing F if any two nonadjacent vertices in opposite partite sets have degree‐sum at least n/2 + τ(F), where τ(F) = ⌈k/2⌉ + ɛ (here ɛ = 1 if t1 = 0 or if (t1, t2)∈{(1, 0), (2, 0)}, and ɛ = 0 otherwise). We show also that this threshold on the degree‐sum is sharp when n>3k. © 2011 Wiley Periodicals, Inc. J Graph Theory 71:1–17, 2012
New Ore‐Type Conditions for H‐Linked Graphs
Authors: Ferrara Michael , Gould Ronald , Jacobson Michael , Pfender Florian , Powell Jeffrey , Whalen Thor 
Published: September 2011

AbstractFor a fixed (multi)graph H, a graph G is H‐linked if any injection f: V(H)→V(G) can be extended to an H‐subdivision in G. The notion of an H ‐linked graph encompasses several familiar graph classes, including k‐linked, k‐ordered and k‐connected graphs. In this article, we give two sharp Ore‐type degree sum conditions that assure a graph G is H ‐linked for arbitrary H. These results extend and refine several previous results on H ‐linked, k‐linked, and k‐ordered graphs. © 2011 Wiley Periodicals, Inc. J Graph Theory 71:69–77, 2012
Seymour's Second Neighborhood Conjecture for Tournaments Missing a Generalized Star
Authors: Ghazal Salman 
Published: September 2011

AbstractSeymour's Second Neighborhood Conjecture asserts that every digraph (without digons) has a vertex whose first out‐neighborhood is at most as large as its second out‐neighborhood. We prove its weighted version for tournaments missing a generalized star. As a consequence the weighted version holds for tournaments missing a sun, star, or a complete graph. © 2011 Wiley Periodicals, Inc. J Graph Theory 71:89–94, 2012
Minors in large almost‐5‐connected non‐planar graphs
Authors: Kawarabayashi Ken‐Ichi , Maharry John 
Published: September 2011

AbstractIt is shown that every sufficiently large almost‐5‐connected non‐planar graph contains a minor isomorphic to an arbitrarily large graph from one of six families of graphs. The graphs in these families are also almost‐5‐connected, by which we mean that they are 4‐connected and all 4‐separations contain a “small” side.As a corollary, every sufficiently large almost‐5‐connected non‐planar graph contains both a K3, 4‐minor and a ‐minor. The connectivity condition cannot be reduced to 4‐connectivity, as there are known infinite families of 4‐connected non‐planar graphs that do not contain a K3, 4‐minor. Similarly, there are known infinite families of 4‐connected non‐planar graphs that do not contain a ‐minor.
The A4‐structure of a graph
Authors: Barrus Michael D. , West Douglas B. 
Published: September 2011

AbstractWe define the A4‐structure of a graph G to be the 4‐uniform hypergraph on the vertex set of G whose edges are the vertex subsets inducing 2K2, C4, or P4. We show that perfection of a graph is determined by its A4‐structure. We relate the A4‐structure to the canonical decomposition of a graph as defined by Tyshkevich [Discrete Math 220 (2000) 201–238]; for example, a graph is indecomposable if and only if its A4‐structure is connected. We also characterize the graphs having the same A4‐structure as a split graph.
The structure of graphs with a vital linkage of order 2
Authors: Mayhew Dillon , Whittle Geoff , van Zwam Stefan H. M. 
Published: September 2011

AbstractA linkage of order k of a graph G is a subgraph with k components, each of which is a path. A linkage is vital if it spans all vertices, and no other linkage connects the same pairs of end vertices. We give a characterization of the graphs with a vital linkage of order 2: they are certain minors of a family of highly structured graphs.
Comparison of four‐dimensional flow parameters for quantification of flow eccentricity in the ascending aorta
Authors: Sigovan Monica , Hope Michael D. , Dyverfeldt Petter , Saloner David 
Published: September 2011

AbstractPurpose:To compare quantitative parameters for assessing the degree of eccentric systolic blood flow in the ascending thoracic aorta (AsAo).Materials and Methods:Forty‐one patients were studied with three‐dimensional (3D), cine phase‐contract MRI (4D Flow). Analysis was performed at peak systole for a cross‐sectional plane in the AsAo just distal to the sinotubular junction. AsAo flow was graded as normal, mildly, or markedly eccentric based on qualitative visual assessment. For quantitative analysis, flow jet angle and normalized flow displacement from the vessel center were calculated.Results:Patients with normal AsAo systolic flow (n = 25) had an average flow jet angle of 13.7 degrees and flow displacement 0.04. These parameters were significantly elevated for patients with mild eccentric systolic flow (n = 6): 24.6 degrees (P = 0.012) and 0.12 (P = 0.001), respectively. However, for patients with marked eccentric flow (n = 10), only flow displacement was significantly elevated compared with the mild eccentric group (0.18; P = 0.04); flow angle was 25.7 degrees.Conclusion:Flow displacement is a more reliable quantitative parameter for measuring eccentric AsAo systolic flow than flow jet angle, and should be evaluated in studies investigating the role of eccentric flow in the promotion of aortic pathology. J. Magn. Reson. Imaging 2011;. © 2011 Wiley Periodicals, Inc.
Comparison of matrix metalloproteinase activation after focal cortical ischemia in young adult and aged mice
Authors: Liguz‐Lecznar Monika , Ziemka‐Nalecz Malgorzata , Aleksy Monika , Kossut Malgorzata , Skangiel‐Kramska Jolanta , Nowicka Dorota 
Published: September 2011

AbstractMatrix metalloproteinase (MMP) activity is implicated in the degradation of the extracellular matrix during cerebral ischemia. Although many studies have demonstrated spatiotemporal patterns of activation of gelatinases (MMP‐9 and MMP‐2) after ischemic stroke in young adult rodents, no data exist on MMP activity in old brains. In this study, we investigated the gelatinolytic activity in young adult (3‐month‐old) and aged (1‐year‐old) mice subjected to photothrombotic stroke. Using in situ zymography and gel zymography, we found that the basal gelatinolytic activity in the intact cerebral cortex was similar at both investigated ages. Similarly, after photothrombosis, the increased gelatinolytic response up to 7 days poststroke was the same in young and aged brains. At both ages, early activation of gelatinolysis in the ischemic core and the perilesional area was present in neuronal nuclei as revealed by colocalization of gelatinolytic product with NeuN immunostaining and DAPI. Additionally, application of specific antibodies against MMP‐9 and MMP‐2 revealed the increase in MMP‐9 immunoreactivity in cell nuclei as early as 4 hr poststroke. No differences between young and aged mice were observed concerning the level and localization of MMP‐9 immunoreactivity. The lack of age‐related differences in the degree and pattern of activation of gelatinolysis after focal stroke and the lack of correspondence between the results of in situ and gel zymography suggest that extracellular proteolysis is not directly responsible for the more severe outcome of ischemic stroke in aged subjects. © 2011 Wiley Periodicals, Inc.
Excitatory effect of histamine on rat spinal motoneurons by activation of both H1 and H2 receptors in vitro
Authors: Wu Guan‐Yi , Han Xiao‐Hu , Zhuang Qian‐Xing , Zhang Jun , Yung Wing‐Ho , Chan Ying‐Shing , Zhu Jing‐Ning , Wang Jian‐Jun 
Published: September 2011

AbstractThe central histaminergic nervous system, originating from the tuberomammillary nucleus of the hypothalamus, widely innervates almost the whole brain as well as the spinal cord. However, the effect of histamine on spinal motoneurons, the final common path for motor control, is still unknown. By using 8–14‐day‐old rat spinal slice preparations and intracellular recordings, the effect of histamine on motoneurons in lumbar spinal cord and the underlying mechanisms were studied. Bath application of histamine (30–300 μM) induced a membrane depolarization in the majority of recorded spinal motoneurons (78/90, 86%). Perfusing slices with tetrodotoxin or low‐Ca2+/high‐Mg2+ medium did not block the histamine‐induced excitation, indicating a direct postsynaptic action of histamine on motoneurons. Separate application of the selective histamine H1 receptor antagonist mepyramine or the selective histamine H2 receptor antagonist ranitidine partially suppressed the histamine‐induced excitation, whereas a combination of ranitidine and mepyramine totally blocked the excitatory effect of histamine on motoneurons. On the other hand, both the selective histamine H1 receptor agonist 2‐pyridylethylamine and the selective histamine H2 receptor agonist dimaprit mimicked the excitation of histamine on spinal motoneurons. These agonist‐induced excitations were also blocked by mepyramine or ranitidine. Furthermore, histamine affected membrane input resistance and potentiated repetitive firing behavior of spinal motoneurons. These results demonstrate that histamine excites rat spinal motoneurons via the histamine H1 and H2 receptors and increases their excitability, suggesting that the hypothalamospinal histaminergic fibers may directly modulate final motor outputs and actively regulate ongoing motor execution andspinal motor reflexes. © 2011 Wiley Periodicals, Inc.
Epigenetic control of somatostatin and cortistatin expression by β amyloid peptide
Authors: Rubio Alicia , Sánchez‐Mut José V. , García Esther , Velasquez Zahady D. , Oliver Jorge , Esteller Manel , Avila Jesús 
Published: September 2011

Abstractβ Amyloid, present in senile plaques, has been related largely to neuronal loss in the brain of patients with Alzheimer's disease. However, how neurons respond to β amyloid insults is still poorly understood. Here we show that β amyloid increases somatostatin and cortistatin gene expression mainly through an increase in histone 3 lysine 4 methylation (H3K4me3), a modification associated with transcriptional activation. Somatostatin and cortistatin partially decreased β amyloid toxicity in primary cortical neurons in culture. Thus we suggest that neurons respond to β amyloid insults by releasing somatostatin and cortistatin, which will act as a protective agent against β amyloid toxicity. Our results suggest a relevant function for both neuropeptides against β amyloid toxicity, providing new insights into Alzheimer's disease. © 2011 Wiley Periodicals, Inc.