bluuebunny/crossref_metadata_2025_split huggingface dataset:
Großversuche an Spannbetonbrückenträgern zur Beurteilung des Schubtragverhaltens
Authors: Vill Markus , Schweighofer Anton , Kollegger Johann 
Published: February 2012

AbstractDer Brückenbestand im Straßen‐ und Eisenbahnnetz beinhaltet eine Vielzahl an Bauwerken aus Stahlbeton‐ und Spannbeton, die ab Beginn der 1950er Jahre bis Ende der 1970er Jahre errichtet wurden. Diese Tragwerke werden in den nächsten Jahrzehnten zunehmender Belastung durch das ansteigende Verkehrsaufkommen ausgesetzt. In diesem Zusammenhang muss die Fragestellung nach einer ausreichenden Tragfähigkeit und Zuverlässigkeit für Brückenbauwerke beantwortet werden, die jedoch in vielen Fällen gemäß dem heutigen Normenstand nicht positiv bewertet werden kann. Ein besonderes Problem ergibt sich im Betonbau beim Nachweis der Schubtragfähigkeit, zumal früher andere Bemessungskonzepte als heute Grundlage für den Brückenentwurf waren.In dem Zusammenhang wurden drei Versuche zur Ermittlung der Schubtragfähigkeit an Spannbetonbrückenträgern im Maßstab 1:1 durchgeführt, wobei die Träger bis zum Versagen belastet wurden. Die Versuche ergaben hohe Tragreserven gegenüber den rechnerischen Tragfähigkeiten gemäß Eurocode 2. Der vorliegende Beitrag beinhaltet eine Beschreibung der Versuche sowie einen Vergleich der Ergebnisse mit den Bemessungsansätzen gemäß Eurocode.Full scale tests on prestressed concrete bridges concerning the shear load bearing capacityThe current bridge stock of road and railway bridges consists of many bridges, which were built between the 1950s and the end of 1970s. Many of these structures must carry the increasing life loads within the next years at a high level of reliability. Therefore, the question arises whether sufficient load‐carrying‐capacity (according to the state of the art) can still be ensured or not. Especially the structural analysis of the shear‐load‐capacity of concrete structures has been changed over the last 50 years. In many cases the verification of shear load bearing capacity according to Eurocode 2 cannot be done.In the course of the destruction of an underground railway station the ÖBB Bridge Department and the Institute for Structural Engineering at the Vienna University of Technology were given the opportunity to carry out full scale tests concerning the shear load carrying capacity on three bridge girders. The load tests showed big deflections, significant crack widths and a ductile behavior of the T‐beams with a high factor of global safety.The paper includes a description of the bridge structure, the results of the tests, and a comparison of the experimental results with the shear carrying capacity according to Eurocode.
Connexin 57 is expressed by the axon terminal network of B‐type horizontal cells in the rabbit retina
Authors: Pan Feng , Keung Joyce , Kim In‐Beom , Snuggs Mark B. , Mills Stephen L. , O'Brien John , Massey Stephen C. 
Published: February 2012

AbstractIn the rabbit retina there are two types of horizontal cell (HC). A‐type HCs (AHC) are axonless and extensively coupled via connexin (Cx)50 gap junctions. The B‐type HC (BHC) is axon‐bearing; the somatic dendrites form a second network coupled by gap junctions while the axon terminals (ATs) form a third independent network in the outer plexiform layer (OPL). The mouse retina has only one type of HC, which is morphologically similar to the B‐type HC of the rabbit. Previous work suggested that mouse HCs express Cx57 (Hombach et al. [2004] Eur J Neurosci 19:2633–2640). Therefore, we cloned rabbit Cx57 and raised an antibody to determine the distribution of Cx57 gap junctions among rabbit HCs. Dye injection methods were used to obtain detailed fills for all three HC networks for analysis by confocal microscopy. We found that Cx57 was associated with the B‐type AT plexus. Cx57 plaques were anticorrelated with the B‐type somatic dendrites and the A‐type HC network. Furthermore, there was no colocalization between Cx50 and Cx57. We conclude that in the rabbit retina, Cx57 is only found on BHC‐AT processes. Thus, in species where there are two types of HC, different connexins are expressed. The absence of Cx57 labeling in the somatic dendrites of B‐type HCs suggests the possibility of an additional unidentified HC connexin in the rabbit. J. Comp. Neurol. 520:2256–2274, 2012. © 2012 Wiley Periodicals, Inc.
Astrocytes in the rat medial amygdala are responsive to adult androgens
Authors: Johnson Ryan T. , Schneider Amanda , DonCarlos Lydia L. , Breedlove S. Marc , Jordan Cynthia L. 
Published: February 2012

AbstractThe posterodorsal medial amygdala (MePD) exhibits numerous sex differences including differences in volume and in the number and morphology of neurons and astroctyes. In adulthood, gonadal hormones, including both androgens and estrogens, have been shown to play a role in maintaining the masculine character of many of these sex differences, but whether adult gonadal hormones maintain the increased number and complexity of astrocytes in the male MePD was unknown. To answer this question we examined astrocytes in the MePD of male and female Long Evans rats that were gonadectomized as adults and treated for 30 days with either testosterone or a control treatment. At the end of treatment brains were collected and immunostained for glial fibrillary acidic protein. Stereological analysis revealed that adult androgen levels influenced the number and complexity of astrocytes in the MePD of both sexes, but the specific effects of androgens were different in males and females. However, sex differences in the number and complexity of adult astrocytes persisted even in the absence of gonadal hormones in adulthood, suggesting that androgens also act earlier in life to determine these adult sex differences. Using immunofluorescence and confocal microscopy, we found robust androgen receptor immunostaining in a subpopulation of MePD astrocytes, suggesting that testosterone may act directly on MePD astrocytes to influence their structure and function. J. Comp. Neurol. 520:2531–2544, 2012. © 2012 Wiley Periodicals, Inc.
Morphologic evidence for spatially clustered spines in apical dendrites of monkey neocortical pyramidal cells
Authors: Yadav Aniruddha , Gao Yuan Z. , Rodriguez Alfredo , Dickstein Dara L. , Wearne Susan L. , Luebke Jennifer I. , Hof Patrick R. , Weaver Christina M. 
Published: February 2012

AbstractThe general organization of neocortical connectivity in rhesus monkey is relatively well understood. However, mounting evidence points to an organizing principle that involves clustered synapses at the level of individual dendrites. Several synaptic plasticity studies have reported cooperative interaction between neighboring synapses on a given dendritic branch, which may potentially induce synapse clusters. Additionally, theoretical models have predicted that such cooperativity is advantageous, in that it greatly enhances a neuron's computational repertoire. However, largely because of the lack of sufficient morphologic data, the existence of clustered synapses in neurons on a global scale has never been established. The majority of excitatory synapses are found within dendritic spines. In this study, we demonstrate that spine clusters do exist on pyramidal neurons by analyzing the three‐dimensional locations of ∼40,000 spines on 280 apical dendritic branches in layer III of the rhesus monkey prefrontal cortex. By using clustering algorithms and Monte Carlo simulations, we quantify the probability that the observed extent of clustering does not occur randomly. This provides a measure that tests for spine clustering on a global scale, whenever high‐resolution morphologic data are available. Here we demonstrate that spine clusters occur significantly more frequently than expected by pure chance and that spine clustering is concentrated in apical terminal branches. These findings indicate that spine clustering is driven by systematic biological processes. We also found that mushroom‐shaped and stubby spines are predominant in clusters on dendritic segments that display prolific clustering, independently supporting a causal link between spine morphology and synaptic clustering. J. Comp. Neurol. 520:2888–2902, 2012. © 2012 Wiley Periodicals Inc.
Synthetic, Structural, and Catalytic Studies of Well‐Defined Allyl 1,2,3‐Triazol‐5‐ylidene (tzNHC) Palladium Complexes
Authors: Terashima Takahiro , Inomata Sayuri , Ogata Kenichi , Fukuzawa Shin‐ichi 
Published: February 2012

AbstractA series of allyl 1,2,3‐triazol‐5‐ylidene (tzNHC) palladium complexes was prepared, and the structures of the complexes were fully characterized by NMR and X‐ray diffraction analyses. The donor properties of these ligands were evaluated by studying the vibrational spectra of their carbonyliridium complexes and their X‐ray photoelectron spectra. These evaluations showed that the structures of thetzNHC palladium complexes are almost identical to those of the corresponding imidazole carbene palladium complexes, and that thetzNHC ligands have stronger donor properties than the imidazole carbene ligands. The relationship between catalytic activity and structure was examined by carrying out a room‐temperature Suzuki–Miyaura coupling reaction, and the cinnamylpalladium complex bearing 1,4‐bis(2,6‐diisopropylphenyl)‐3‐methyl‐1,2,3‐triazol‐5‐ylidene (TPr) was found to be the most active catalyst. (cinnamyl)(TPr)PdCl showed high activity in the room‐temperature reaction performed with aryl chlorides regardless of the electronic and steric properties of the substituents, and was effective in reactions with sterically crowded arylboronic acids.
Effect of freezing on quality of sea bass and gilthead sea bream
Authors: Nasopoulou Constantina , Demopoulos Constantinos A. , Zabetakis Ioannis 
Published: February 2012

AbstractFreezing is an efficient method of fish preservation. The aim of the present work was to examine the impact of freezing in fatty acid composition and in the in vitro inhibitory activity of sea bass (Dicentrarchus labrax) and gilthead sea bream (Sparus aurata) fillet lipids against platelet activating factor (PAF). The Bligh and Dyer extraction method and the counter‐current distribution method were used to obtain total, polar and neutral lipids. The fatty acid analysis conducted using the internal standard method and the biological assay on washed rabbit platelets took place calculating the in vitro inhibitory activity of fish lipids against 2.5 × 10−11 M of PAF. No statistical changes (p<0.05) occurred in fatty acid content of fresh and thawed gilthead sea bream, while fatty acid amount in thawed sea bass was significantly higher (p<0.05) compared to fresh fish. Total lipids of both thawed fish species exhibited stronger anti‐thrombotic activity compared to fresh fish. Freezing preserved fish quality and reinforced the anti‐thrombotic properties of fish oils, since even after 6 months of freezing, fish oils preserve their nutritional value in terms of protecting against cardiovascular diseases.Practical applications: Fish fillets contain high amount of unsaturated lipids that may easily undergo lipid oxidation. Freezing and frozen storage prevent such oxidative changes so fish quality is retained. Fatty acids and PAF‐antagonists in fish are of major importance since they contribute to the nutritional value of fish. The practical application of this work lies on the evaluation of the nutritional value of fish in terms of cardio protection by examining the impact of freezing on the levels of fatty acids and PAF‐antagonists in aquacultured fish fillets.
The comparison of properties of the oil and kernels of various hazelnuts from Germany and Turkey
Authors: Matthäus Bertrand , Özcan Mehmet Musa 
Published: February 2012

AbstractThe oil yields of hazelnut kernels collected from Germany (Münster) and Turkey range from 8.1 to 64.1%. The main fatty acids in hazelnut kernel oils are oleic (76.3–82.6%), linoleic (6.5–14.0%), and palmitic (5.7–6.5%). The hazelnut kernel oils contained an appreciable amount of α‐tocopherol (19.9–63.9 mg/100 g), with a mean value of 40.02 mg/kg, and γ‐tocopherol (1.3–15.5 mg/100 g), with a mean value of 4.84. α‐Tocopherol was the predominant tocopherol in all hazelnut kernels. The major sterols were β‐sitosterol, ranging from 78.13 to 82.56 mg/kg; campesterol, ranging from 4.79 to 7.42 mg/kg; and δ5‐avanasterol, ranging from 1.26 to 5.24 mg/kg. The highest minerals were K and P followed by Ca, Mg, Na, and Zn. P contents of all samples were established between 2029.90 and 4376.66 ppm. The results may also be useful for the evaluation of nutritional information. As a result, the present study showed that the kernels of hazelnut are a potential source of valuable oil which might be used for food and non‐food applications. In addition, hazelnut kernel oil has a high nutritive value and can be recommended for processing of healthy food products.
Synthesis and Two‐Photon Properties of Small Dendritic Chromophores with Symmetrical and Unsymmetrical Substituted Skeletons
Authors: Lin Tzu‐Chau , Lee Ying‐Hsuan , Hu Chia‐Ling , Li Yu‐Kai , Huang Yu‐Jhen 
Published: February 2012

AbstractA set of novel multi‐branched chromophores consisting of two groups of fluorene/oxadiazole‐based analogues with generic skeletons of donor‐π‐acceptor (unsymmetrical) and donor‐π‐acceptor‐π‐donor (symmetrical) type has been synthesized and shown to display strong and broadly dispersed two‐photon absorptivities in the near infrared (NIR) region on irradiation with femtosecond laser pulses. It is also demonstrated that structural parameters such as the number of donor units attached and the substitution pattern are closely connected to the molecular two‐photon activities of these model compounds.
Combating channel eviction triggering denial‐of‐service attacks in cognitive radio networks
Authors: Sodagari Shabnam , Attar Alireza , Leung Victor C.M. , Bilén Sven G. 
Published: February 2012

ABSTRACTWe focus on a specific class of denial‐of‐service (DoS) attacks that is executed through Channel Eviction Triggering (CET), whereby adversary nodes unduly invoke mechanisms inherent in a cognitive radio (CR) network (CRN) operation to protect the licensed users and thus disrupt secondary access to the otherwise idle licensed bands. Skewing the spectrum sensing decision of CRN through sensing misreports is a manifestation of CET attacks. Whereas most studies in the literature focus on making the cooperative sensing more robust against such sensing misreports, we tackle the problem from the novel perspective of incentive alleviation. We distinguish two classes of such DoS attacks, which we refer to as CET and CET‐jamming attacks. In the former case, the incentive of adversary CRs is to remove the competition of truthful CRs in accessing the licensed spectral ranges. The latter class of DoS attack deals with scenarios in which the adversary nodes are mainly interested in denying the chances of communication of CRN over primary bands and as such their incentive cannot be modelled by the same utility maximisation model as truthful CRs. We propose a solution for each class of attacks, and our numerical results verify the effectiveness of the proposed CET defence scheme in both cases. Copyright © 2012 John Wiley & Sons, Ltd.
P2X4 receptor channels form large noncytolytic pores in resting and activated microglia
Authors: Bernier Louis‐Philippe , Ase Ariel R. , Boué‐Grabot Éric , Séguéla Philippe 
Published: February 2012

AbstractP2X4 ATP‐gated cation channels have been shown to contribute to the microglial component of central sensitization, making their functional regulation a key element in chronic pain pathologies. Here we show that prolonged activation of native P2X4 receptor channels by ATP induces opening of a pore permeable to NMDG+ and large fluorescent dyes in BV‐2 microglial cells and primary murine microglia. This intrinsic pore formation mechanism is potentiated by LPS treatment, known to upregulate P2X4 expression in microglial cells and to mimic the microglial activation observed in neuropathic pain states. Sustained activation of the P2X7 channel subtype, also expressed in microglia, induces a pore formation that requires pannexin hemichannels and leads to plasma membrane blebbing and cytotoxicity. In contrast, P2X4 pore formation is unaffected by the pannexin blocker carbenoxolone, does not induce cytoskeletal rearrangements and does not lead to cell death. Furthermore, we show that P2X4 pore dilation is modulated by phosphoinositides (PIPn) levels as it is inhibited by wortmannin, a blocker of PIPn synthesis, suggesting possible regulation by phospholipase C‐coupled pathways. Nonlethal P2X4 pore dilation could play a role in neuropathic pain by allowing the flux of large organic molecules in microglia. Different outcomes of P2X4 and P2X7 membrane permeabilization point to subtype‐specific microglial responses to ATP in normal and pathological neuro‐immune crosstalks. © 2012 Wiley Periodicals, Inc.
The magnitude of the antigen‐specific T cell response is separated from the severity of spinal cord histopathology in remitting‐relapsing experimental autoimmune encephalomyelitis
Authors: Batoulis Helena , Uhl Martin , Addicks Klaus , Lehmann Paul V. , Kuerten Stefanie 
Published: February 2012

AbstractMultiple sclerosis (MS) is an autoimmune disorder of the central nervous system. The remitting‐relapsing experimental autoimmune encephalomyelitis (EAE) in the SJL mouse strain is a common animal model for MS and similar to the human disease it is considered to be T helper cell mediated. Besides interferon‐γ secreting TH1 cells in particular the TH17 subset is believed to be highly pathogenic. Spreading of the TH1 and TH17 response to newly emerging determinants has been used to explain clinical disease relapse, but if the magnitude of the TH1/TH17 response is linked to clinical relapse severity has remained unresolved. Here, we assessed clinical EAE severity, the extent of spinal cord histopathology and the magnitude of the antigen‐specific T helper cell and autoantibody response in proteolipid protein peptide 139–151 (PLP:139–151)‐immunized SJL mice in clinical remission and relapse. We demonstrate that spinal cord histopathology comprised inflammation, demyelination as well as axonal loss and correlated well with clinical disease severity. Although the degree of spinal cord histopathology and clinical severity was separated from the PLP:139–151‐specific TH1/TH17 cell and antibody response, it was linked to the number of infiltrating macrophages and activated microglia. In particular, there was a correlation between their secretion product interleukin‐1β and the degree of axonal loss. Although CD4+ T cells seem to be mainly involved in disease initiation, we suggest that it is the downstream activation of the innate immune response that defines the magnitude of the disease outcome. © 2012 Wiley Periodicals, Inc.
Disruption of Staphylococcus epidermidis biofilm formation using a targeted cationic peptide
Authors: Hofmann Christopher M. , Bednar Kyle J. , Anderson James M. , Marchant Roger E. 
Published: February 2012

AbstractThis study reports the use of a targeted cationic peptide with the ability to disrupt Staphylococcus epidermidis biofilm formation. Complications due to nosocomial infections of implanted medical devices pose a significant health risk to patients, with Staphylococcus epidermidis often implicated in the case of blood‐contacting biomaterials. S. epidermidis virulence relies mainly on its ability to form a biofilm, the main component of which is polysaccharide intercellular adhesin (PIA). We utilized the synthetic β6‐20 peptide, known to specifically bind S. epidermidis, in order to deliver a cationic polylysine peptide (G3K6) to the bacterial surface and disrupt the charge–charge interactions needed for PIA retention and biofilm stability. The effects of the β6‐20‐G3K6 peptide on biofilm formation were assessed using optical density, fluorescently labeled wheat germ agglutinin, nucleic acid stain (SYTO 9), and a metabolic assay (XTT, 2,3‐bis(2‐methoxy‐4‐nitro‐5‐sulfophenyl)‐2H‐tetrazolium‐5‐carboxanilide inner salt). Biofilms formed in the presence of β6‐20‐G3K6 peptide (100 μM) resulted in a 37.9% reduction in PIA content and a 17.5% reduction of adherent bacteria relative to biofilms grown in the absence of peptide. These studies demonstrate the targeting ability of the β6‐20 peptide towards biomaterial‐adherent S.
epidermidis, and highlight the potential for disrupting the early stages of biofilm formation. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2012.
Osteoblast activity on carbonated hydroxyapatite
Authors: Rupani Asha , Hidalgo‐Bastida Lilia Araida , Rutten Frank , Dent Andrew , Turner Irene , Cartmell Sarah 
Published: February 2012

AbstractHydroxyapatite (HA), has been used commonly as a bone substitute and as a scaffold in bone tissue engineering. However it has certain drawbacks such as limited biodegradability and osteointegration properties. Other forms of HA, for example, carbonated hydroxyapatite (CHA) could prove to have enhanced bioactivity as they more closely mimic the chemical composition of the apatite found in human bone. The aim of this study was to test the efficacy of CHA in comparison to HA used as a control. The CHA (4.9 wt %) and the HA discs were seeded with MC3T3‐E1 osteoblastic cells. Results revealed a trend of increased cell attachment on the HA discs at day 0, however, the cell proliferation on the CHA discs at 7 and 28 days showed no significant difference in comparison to the HA control. SEM of the CHA discs showed surface irregularities at 7 days indicating dissolution. Also at 7 days, SEM demonstrated cell attachment and extracellular matrix production on both the CHA and HA samples. There was no significant difference in the total amount of collagen produced in the CHA samples relative to the HA control samples at 28 days as evaluated by the hydroxyproline assay. Real time PCR revealed mRNA increase by 2.08, 7.62, and 9.86 fold for collagen I a1, collagen III a1, and osteocalcin respectively on the CHA as compared to the HA discs. This study demonstrates the use of CHA as a biocompatible material that has potentially increased biodegradation properties and osteogenic capability in comparison to HA. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2012.
A [Fe(CB6)] platform for binding of small molecules: Insights from DFT calculations
Authors: Baskaran Sambath , Tamizmani Masilamani , Mahalakshmi Thanigachalam , Sivasankar Chinnappan 
Published: February 2012

AbstractThe viability of making [Fe(CB6)L] (L = H2, N2, O2, nitric oxide [NO−, NO, and NO+], CO2, and hydrocarbons [CH4, C2H6, C2H4, and C6H6]) has been investigated by density functional theory (DFT) calculations. The complexes 2–18 are thermodynamically stable and may be synthesized. The small molecules are activated to some extent after complexation. Molecular orbital and ΔG calculation revealed that the molecular hydrogen and hydrocarbons can be chemically adsorbed and desorbed on [Fe(CB6)] without any significant chemical modification and therefore [Fe(CB6)] may serve as a storage material. The N2, O2, and nitric oxide (NO−, NO, and NO+) can be activated using [Fe(CB6)]. Proton, carbon, boron, and nitrogen NMR chemical shift calculation predicts drastic chemical shift difference before and after the complexation of [Fe(CB6)] with small molecules. This new findings suggest that the CB62− ligand‐based complex may provide several applications in the future. © 2012 Wiley Periodicals, Inc.