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Different Interactions (different + interaction)
Selected AbstractsExhaled nitric oxide and exercise-induced bronchoconstriction in young wheezy children , interactions with atopyPEDIATRIC ALLERGY AND IMMUNOLOGY, Issue 7 2009L. Pekka Malmberg The association between exercise-induced bronchoconstriction (EIB) and exhaled nitric oxide (FENO) has not been investigated in young children with atopic or non-atopic wheeze, two different phenotypes of asthma in the early childhood. Steroid naïve 3- to 7-yr-old children with recent wheeze (n = 84) and age-matched control subjects without respiratory symptoms (n = 71) underwent exercise challenge test, measurement of FENO and skin prick testing (SPT). EIB was assessed by using impulse oscillometry, and FENO by standard online technique. Although FENO levels were highest in atopic patients with EIB, both atopic and non-atopic wheezy children with EIB showed higher FENO than atopic and non-atopic control subjects, respectively. In atopic wheezy children, a significant relationship between FENO and the severity of EIB was found (r = 0.44, p = 0.0004), and FENO was significantly predictive of EIB. No clear association between FENO and EIB or predictive value was found in non-atopic wheezy children. Both atopic and non-atopic young wheezy children with EIB show increased FENO levels. However, the association between the severity of EIB and FENO is present and FENO significantly predictive of EIB only in atopic subjects, suggesting different interaction between bronchial responsiveness and airway inflammation in non-atopic wheeze. [source] Large-scale phosphoproteome analysis of human liver tissue by enrichment and fractionation of phosphopeptides with strong anion exchange chromatographyPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 7 2008Guanghui Han Abstract The mixture of phosphopeptides enriched from proteome samples are very complex. To reduce the complexity it is necessary to fractionate the phosphopeptides. However, conventional enrichment methods typically only enrich phosphopeptides but not fractionate phosphopeptides. In this study, the application of strong anion exchange (SAX) chromatography for enrichment and fractionation of phosphopeptides was presented. It was found that phosphopeptides were highly enriched by SAX and majority of unmodified peptides did not bind onto SAX. Compared with Fe3+ immobilized metal affinity chromatography (Fe3+ -IMAC), almost double phosphopeptides were identified from the same sample when only one fraction was generated by SAX. SAX and Fe3+ -IMAC showed the complementarity in enrichment and identification of phosphopeptides. It was also demonstrated that SAX have the ability to fractionate phosphopeptides under gradient elution based on their different interaction with SAX adsorbent. SAX was further applied to enrich and fractionate phosphopeptides in tryptic digest of proteins extracted from human liver tissue adjacent to tumorous region for phosphoproteome profiling. This resulted in the highly confident identification of 274 phosphorylation sites from 305 unique phosphopeptides corresponding to 168 proteins at false discovery rate (FDR) of 0.96%. [source] Importance of Interaction between C1 Domain and Lipids in Protein Kinase C, Activation: Hydrophobic Side Chain Direction in Isobenzofuranone Ligands Controls Enzyme Activation LevelCHEMMEDCHEM, Issue 7 2007Go Hirai Dr. Substituent direction is important: Type A,D isobenzofuranone derivatives were synthesized with differently directed hydrophobic alkyl side chains. These ligands bind in a similar conformation to protein kinase C, but have contrasting activation abilities, possibly owing to different interaction of the side chain with the membrane lipid. [source] A Highly Enantioselective Receptor for Carbamoyl Lactic Acid,EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 31 2009Francisco M. Muñiz Abstract A new receptor based on a 9,9-dimethylxanthene framework was synthesized. Owing to its suitable oxyanion hole structure, this receptor is able to associate carboxylic acids and anions. The introduction of a chiral center provides enantioselective properties to this receptor as a result of its different interactions with both enantiomers of the substrate. The combination of this skeleton with a fluorescent unit such as dansyl allows the detection of small amounts of carboxylic acids by making use of fluorescent techniques.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Experimental Approaches for Controlling Current Flowing through Metal,Molecule,Metal Junctions,ADVANCED MATERIALS, Issue 10 2006E. Tran Abstract Two experimental approaches that enable control of current flow through metal,molecules,metal junctions are described. A number of studies using two-electrode metal,molecules,metal junctions have shown that the current between the electrodes depends on the structures of the incorporated molecules. When a tunneling mechanism dominates electron transport through organic molecules, the molecules behave similar to resistors with resistivities that can be controlled by changing the structure. Incorporation of molecules with increasing conjugation into Hg-based junctions increases the current flow dramatically. Alternatively, by using four-electrode electrochemical junctions that allow the potential of the electrodes to be controlled with respect to the energy levels of the incorporated molecules, it is possible to change the mechanism of electron transfer and produce abrupt increases in the current flow. These signals, analogous to solid-state diodes, are particularly significant for molecular electronics. Electrochemical junctions also permit prediction of the value of the applied potential at which the current will start taking off and to identify the mechanism of charge transport. New and recently published results obtained using junctions based on Hg electrodes in an "electrochemical" mode show that two junctions incorporating redox centers by different interactions behave as current switches, with the current flow dominated by different charge-transport mechanisms. [source] Predictive models of the combined effects of curvaticin 13, NaCl and pH on the behaviour of Listeria monocytogenes ATCC 15313 in brothJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2000A. Bouttefroy Thirty-three strains of Listeria monocytogenes belonging to different serotypes were tested for their sensitivity to curvaticin 13, an antilisterial bacteriocin produced by Lactobacillus curvatus SB13, using the well diffusion method in Institut Pasteur agar plates at 37 °C. No relationship between serotype and sensitivity was observed. The sensitivity of this species was strain-dependent and a large variation in tolerance to curvaticin 13 was observed. The combined effects of curvaticin 13 (0,160 AU ml,1), NaCl (0,6% w/v), pH values (5·0,8·2) and incubation time (0,24 h) were investigated on L. monocytogenes ATCC 15313 in trypcase soy,yeast extract broth at 22 °C. For this study, two Doehlert matrices were used in order to investigate the main effects of these factors and their different interactions. The results were analysed using the Response Surface Methodology. Curvaticin 13 had a major inhibitory effect and the response was NaCl concentration-, time- and pH-dependent. This inhibitory activity was the same at pH values between 6·6 and 8·2. Curvaticin 13 was bactericidic at acidic pH values, but the surviving cells resumed growth. For a short incubation time (12 h), the effectiveness of curvaticin 13 was maximal in the absence of NaCl. For longer incubation times (12,48 h), with high NaCl (6%) and curvaticin 13 concentrations (160 AU ml,1), the inhibition of L. monocytogenes was greater than that observed with NaCl or curvaticin 13 alone. [source] Modelling space use and dispersal of mammals in real landscapes: a tool for conservationJOURNAL OF BIOGEOGRAPHY, Issue 4 2003David W. Macdonald Abstract Aim To explore the usefulness of Spatially Explicit Population Models (SEPMs), incorporating dispersal, as tools for animal conservation, as illustrated by the contrasting cases of four British mammals. Methods For each of the four species (American mink, Mustela vison, pine marten, Martes martes, dormouse, Muscardinus avellanarius and water vole, Arvicola terrestris) a spatial dynamics model was developed based on an integrated geographical information system (GIS) population model that linked space use to the incidence of the species. Each model had, first, a GIS, which stored environmental, habitat and animal population information, and secondly, an individual-based population dynamics module, which simulated home range formation, individual life histories and dispersal within the GIS-held landscape. Results The four models illustrated different interactions between species life-history variables and the landscape, particularly with respect to dispersal. As water voles and dormice occupy home ranges that are small relative to blocks of their habitat, they were most effectively modelled in terms of the dynamics of local populations within habitat blocks but linked by dispersal. In contrast, because the home ranges of American mink and pine marten are large relative to blocks of habitat, they were best modelled as individuals moving through a landscape of more or less useful patches of habitat. For the water vole, the most significant predictors of population size were the carrying capacity of each habitat and the annual number of litters. For the dormouse, the likelihood of catastrophe and the upper limit to dispersal movement were the key variables determining persistence. Adult mortality and home-range size were the only significant partial correlates of total population size for the American mink. Adult mortality was also a significant correlate of total population size in the pine marten, as were litter size and juvenile mortality. In neither the marten nor the mink was dispersal distance a significant factor in determining their persistence in the landscape. Main conclusions At a landscape scale it is difficult to measure animal distributions directly and yet conservation planning often necessitates knowledge of where, and in what numbers, animals are found, and how their distributions will be affected by interventions. SEPMs offer a useful tool for predicting this, and for refining conservation plans before irreversible decisions are taken in practice. [source] Application of CAMD in separating hydrocarbons by extractive distillationAICHE JOURNAL, Issue 12 2005Biaohua Chen Abstract The solvent is the core of extractive distillation, and a suitable solvent plays an important role in the economical design of extractive distillation. Computer-aided molecular design (CAMD) has been applied to rapidly screen the solvents for separating hydrocarbons by extractive distillation. The systems of propane/propylene, n-butane/1-butene, and n-heptane/benzene, respectively, as the representatives of C3, C4, and C6 hydrocarbons were investigated, and the potential solvents were selected by means of CAMD. The designed results were further proven by experiments and process simulation. The mechanism for separating hydrocarbons by extractive distillation is based on the different fluidities of the electron cloud of CC (no double bond), CC (one double bond), and ACH (aromatic carbon ring) bonds and thus different interactions between solvent and hydrocarbon molecules. To improve the separation ability of the main solvent, one strategy is to add some additive that can form hydrogen bonding with the main solvent to make into a mixture. © 2005 American Institute of Chemical Engineers AIChE J, 2005 [source] Virus-Vector Cell Interactions Regulating Transmission Specificity of Soybean Dwarf LuteovirusesJOURNAL OF PHYTOPATHOLOGY, Issue 6 2000F. E. Gildow Abstract Transmission of soybean dwarf viruses (SbDV) indigenous to Japan (SbDV-D) and to the eastern United States (SbDV-Va19) were compared in vector and nonvector aphid species. Absolute vector-specificity was maintained when Aulacorthum solani, Acyrthosiphon pisum, and Myzus persicae were allowed to feed on solutions of either virus (100 ,g/ml) through Parafil© membranes. SbDVD was transmitted only by A. solani, and SbDV-Va19 was transmitted only by A. pisum and M. persicae. Similar results were obtained when individual aphids were micro-injected with 2 ng virus and subsequently allowed to feed on healthy plants. Ultrastructural studies of A. solani and M. persicae indicated that both SbDV-D and SbDV-Va20 were acquired specifically through the aphid hindgut. No difference in hindgut acquisition specificity was observed, and both A. solani and M. persicae were able to transport SbDV-D and SbDV-Va20 into the haemocoel by endocytotic/exocytotic pathways. When injected, SbDV was shown to be associated with only the accessory salivary glands (ASG) in aphids, indicating a high level of tissue specificity. Two different interactions with the ASG were observed for SbDV-D and SbDV-Va20 in A. solani and M. persicae. SbDV-D penetrated the ASG basal lamina of A. solani, but was never observed in the basal lamina of M. persicae. The ASG basal lamina was a barrier to SbDV-D transmission by M. persicae. SbDV-Va19 penetrated the ASG basal lamina of both A. solani and M. persicae. However, SbDV-Va20 was not observed in the ASG cytoplasm in A. solani, indicating that the basal plasmalemma functioned as the transmission barrier. Observations indicated that capsid protein structure, aphid basal lamina composition and cell membrane components influenced virus-aphid interactions regulating SbDV transmission. Zusammenfassung Die Übertragung von Verzwergungsviren der Sojabohne (SbDV), die aus Japan (SbDV-D) bzw. dem Osten der USA (SbDV-Va20) stammten, wurde in Vektor und Nichtvektor-Blattlausarten geprüft. Eine absolute Vektorspezifität wurde stets festgestellt, wenn Aulacorthum solani, Acyrthosiphon pisum und Myzus persicae Lösungen mit einem der Viren (100 ,gml -1) durch Parafilm© Membranen aufnehmen konnten. SbDV-D wurde nur von A. solaniübertragen, SbDV-Va20 nur von A. pisum und M. persicae.Ähnliche Ergebnisse wurden erhalten, wenn einzelne Blattläuse Mikroinjektionen mit 2 ng Virus erhielten und anschließend an gesunden Pflanzen saugen konnten. Feinstrukturelle Untersuchungen von A. solani und M. persicae ergaben, daß SbDV-D und SbDV-Va20 spezifisch durch den Enddarm der Blattläuse aufgenommen wurden. Bei der Aufnahme durch den Enddarm wurde keine unterschiedliche Spezifität festgestellt; A. solani und M. persicae konnten SbDV-D und SbDV-Va20 durch Endo-/Exocytose in die Leibeshöhle aufnehmen. Nach Injektion wurde SbDV bei Blattläusen nur in Assoziation mit den akzessorischen Speicheldrüsen (ASG) beobachtet, was auf eine hohe Gewebsspezifität hindeutet. SbDV-D und SbDV-Va20 zeigten in A. solani und M. persicae zwei unterschiedliche Reaktionen mit den ASG. SbDV-D penetrierte die Basalmembran der ASG von A. solani, wurde in der Basalmembran von M. persicae jedoch in keinem Fall gefunden. Die Basalmembran der ASG fungierte bei M. persicae als Hindernis für eine Übertragung von SbDV-D. SbDV-Va20 penetrierte die Basalmembranen von A. solani und von M. persicae. SbDV-Va20 wurde im ASG-Cytoplasma von A. solani jedoch nicht festgestellt, was darauf hindeutet, daß das Basalplasmalemma als Übertragungshindernis fungierte. Unsere Beobachtungen zeigen, daß die Struktur des Hüllproteins, die Zusammensetzung der Basalmembranen der Blattläuse und die Zellwandbestandteile die Interaktionen zwischen Viren und Blattläusen beeinflussen, welche die SbDV-Übertragung regulieren. [source] Melatonin enhances the rewarding properties of morphine: involvement of the nitric oxidergic pathwayJOURNAL OF PINEAL RESEARCH, Issue 4 2007Noushin Yahyavi-Firouz-Abadi Abstract:, Melatonin has different interactions with opioids including the enhancement of the analgesic effects of morphine and also reversal of tolerance and dependence to morphine. The present study assessed the effect of melatonin on morphine reward in mice using a conditioned place preference (CPP) paradigm. Our data showed that subcutaneous administration of morphine (1,7.5 mg/kg) significantly increased the time spent in the drug-paired compartment in a dose-dependent manner. Intraperitoneal (i.p.) administration of melatonin (1,40 mg/kg) alone did not induce either CPP or conditioned place aversion (CPA), while the combination of melatonin (5,20 mg/kg) and sub-effective dose of morphine (0.5 mg/kg) led to rewarding effect. We further investigated the involvement of the nitric oxidergic pathway in the enhancing effect of melatonin on morphine CPP, by a general nitric oxide synthase inhibitor, NG -nitro- l -arginine methyl ester (l -NAME). l -NAME (1 and 5 mg/kg, i.p.) alone or in combination with morphine (0.5 mg/kg) did not show any significant CPP or CPA. Co-administration of l -NAME (5 mg/kg) with an ineffective combination of melatonin (1 mg/kg) plus morphine (0.5 mg/kg) produced significant CPP that may imply the similarity of action of melatonin and l -NAME and involvement of the nitric oxidergic pathway in this regard. Our results indicate that pretreatment of animals with melatonin enhances the rewarding properties of morphine via a mechanism which may involve the nitric oxidergic pathway. [source] Effect of an aliphatic spacer group on the adsorption mechanism on the colloidal silver surface of L -proline phosphonodipeptidesJOURNAL OF RAMAN SPECTROSCOPY, Issue 12 2008Edyta Podstawka Abstract A comparative study of molecular structures of five L -proline (L -Pro) phosphonodipeptides: L -Pro-NH-C(Me,Me)-PO3H2 (P1), L -Pro-NH-C(Me,iPr)-PO3H2 (P2), L -Pro- L -NH-CH(iBu)-PO3H2 (P3), L -Pro- L -NH-CH(PA)-PO3H2 (P4) and L -Pro- L -NH-CH(BA)-PO3H2 (P5) has been carried out using Raman and absorption infrared techniques of molecular spectroscopy. The interpretation of the obtained spectra has been supported by density functional theory calculations (DFT) at the B3LYP; 6,31 + + G** level using Gaussian 2003 software. The surface-enhanced Raman scattering (SERS) on Ag-sol in aqueous solutions of these phosphonopeptides has also been investigated. The surface geometry of these molecules on a silver colloidal surface has been determined by observing the position and relative intensity changes of the Pro ring, amide, phosphonate and so-called spacer (,R) groups vibrations of the enhanced bands in their SERS spectra. Results show that P4 and P5 adsorb onto the silver as anionic molecules mainly via the amide bond (,1630, ,1533, ,1248, ,800 and ,565 cm,1), Pro ring (,956, ,907 and ,876 cm,1) and carboxylate group (,1395 and ,909 cm,1). Coadsorption of the imine nitrogen atom and PO group with the silver surface, possibly by formation of a weaker interaction with the metal, is also suggested by the enhancement of the bands at 1158 and 1248 cm,1. P1, P2 and P3 show two orientations of their main chain on the silver surface resulting from different interactions of the CCH3, NH and CONH fragments with this surface. Bonding to the Ag surface occurs mainly through the imino atom (1166 cm,1) for P2, while for P1 and P3 it occurs via the methyl group(s) (1194,1208 cm,1). The amide group functionality (CONH) is practically not involved in the adsorption process for P1 and P2, whereas the CsP bonds do assist in the adsorption. Copyright © 2008 John Wiley & Sons, Ltd. [source] Protein thermal stability and phospholipid,protein interaction investigated by capillary isoelectric focusing with whole column imaging detectionJOURNAL OF SEPARATION SCIENCE, JSS, Issue 7 2006Tao Bo Abstract CIEF with whole column imaging detection (WCID) is an attractive technique for studying protein reaction and protein,ligand interaction due to its fast separation, simple operation, and high efficiency. In this study, two interesting applications by the CIEF-WCID were developed, involving the study of protein thermal stability and phospholipid,protein interaction. Four proteins (,-lactoglobulin B, trypsin inhibitor, phosphorylase b, and trypsinogen) with different pI, and two types of phospholipids, including phosphatidylcholine (PC) and phosphatidylserine (PS), were used for this purpose. First, the altered CIEF profiles of four proteins were exhibited due to conformational changes resulting from protein denaturation induced by a high incubation temperature at 60°C. It was demonstrated that the addition of a zwitterionic phospholipid (PC) played a crucial role in the thermal stability of targeted proteins, especially for trypsin inhibitor whose thermal stability was promoted with the addition of the PC vesicles at 60°C. Second, the zwitterionic (PC) and acidic (PS) phospholipids displayed completely different interactions with the proteins. The addition of PS vesicles modified the zwitterionic phospholipids to carry negative charges, which correspondingly changed the interaction between the phospholipid and the protein. Our study demonstrates that the CIEF-WCID is a powerful approach to study protein reaction and protein,ligand interaction with high efficiency, high selectivity, and fast separation. [source] Linear and Nonlinear Viscoelasticity of a Model Unentangled Polymer Melt: Molecular Dynamics and Rouse Modes AnalysisMACROMOLECULAR THEORY AND SIMULATIONS, Issue 3 2006Mihail Vladkov Abstract Summary: Using molecular dynamics simulations, we determine the linear and nonlinear viscoelastic properties of a model polymer melt in the unentangled regime. Several approaches are compared for the computation of linear moduli and viscosity, including Green-Kubo and nonequilibrium molecular dynamics (NEMD). An alternative approach, based on the use of the Rouse modes, is also discussed. This approach could be used to assess local viscoelastic properties in inhomogeneous systems. We also focus on the contributions of different interactions to the viscoelastic moduli and explain the microscopic mechanisms involved in the mechanical response of the melt to external solicitation. [source] Extended Car,Parrinello molecular dynamics and electronic g -tensors study of benzosemiquinone radical anion,MAGNETIC RESONANCE IN CHEMISTRY, Issue S1 2005James R. Asher Abstract Car-Parrinello molecular dynamics simulations of benzoquinone and benzosemiquinone radical anion in both aqueous solution and the gas phase have been carried out at ambient conditions. Hydrogen bonding is considerably more extensive to the anionic than to the neutral aqueous system. In addition to the conventional hydrogen bonding to the carbonyl oxygen atoms, T-stacked hydrogen bonding to the , -system is statistically and energetically significant for the semiquinone anion but not for the neutral quinone. EPR g -tensors have been calculated at DFT level for snapshots taken at regular intervals from the gas-phase and solution semiquinone anion trajectories. Different criteria for extraction of semiquinone/water clusters from the solution trajectory give insight into the effects of different interactions on the g -tensor, as does correlation of the g -tensor with statistically significant hydrogen-bond configurations identified along the trajectories. Comparison of gas-phase and solution results indicates opposite directions of direct electronic and indirect structural influences of hydrogen bonding on g -tensors. Short-time oscillations in gx along the trajectory are due mainly to CO bond vibrations. Copyright © 2005 John Wiley & Sons, Ltd. [source] Students' and teachers' perceived and actual verbal interactions in seminar groupsMEDICAL EDUCATION, Issue 4 2009A Debbie C Jaarsma Objectives, This study set out to examine how much time students and teachers devote to different learning-oriented interactions during seminar sessions and students' and teachers' perceptions about the occurrence and desirability of these interactions. Methods, Students and teachers participating in eight seminar group sessions in Year 4 of an undergraduate veterinary curriculum completed an 11-item questionnaire which asked them to rate, on a 5-point Likert scale, the frequency of occurrence and level of desirability of three learning-oriented types of interaction: exploratory questioning; cumulative reasoning, and handling of conflict about knowledge. The questionnaire also invited positive and negative responses to aspects of group interactions and an overall mark (1,10) for the seminars and group interactions. Four group sessions were video-recorded and analysed using a coding scheme. The amount of time devoted to the different interactions was calculated. Results, Both students and teachers gave scores of 3.0,3.5 for frequency of occurrence of exploratory questioning and cumulative reasoning and < 3.0 for occurrence of handling of conflict about knowledge. The desired occurrences of all interaction types were significantly higher than the actual occurrences according to students and teachers. Teachers were responsible for the majority of the interactions (93%). The percentages of session time devoted to teacher-centred cumulative reasoning, exploratory questioning and handling of conflict about knowledge were 65.8%, 15.6% and 3.1%, respectively. Conclusions, Group interactions in seminar groups are dominated by the posing of questions by teachers to students. The moderate occurrence of group interactions as perceived by students and teachers may be explained by the inadequate preparation of teachers and students to stimulate group interactions. [source] Characterisation of Nanohybrids of Porphyrins with Metallic and Semiconducting Carbon Nanotubes by EPR and Optical SpectroscopyCHEMPHYSCHEM, Issue 13 2008Sofie Cambré Abstract Single-walled carbon nanotubes (SWCNTs) are noncovalently functionalised with octaethylporphyrins (OEPs) and the resulting nanohybrids are isolated from the free OEPs. Electron paramagnetic resonance (EPR) spectroscopy of cobalt(II)OEP, adsorbed on the nanotube walls by ,,,-stacking, demonstrates that the CNTs act as electron acceptors. EPR is shown to be very effective in resolving the different interactions for metallic and semiconducting tubes. Moreover, molecular oxygen is shown to bind selectively to nanohybrids with semiconducting tubes. Water solubilisation of the porphyrin/CNT nanohybrids using bile salts, after applying a thorough washing procedure, yields solutions in which at least 99,% of the porphyrins are interacting with the CNTs. Due to this purification, we observe, for the first time, the isolated absorption spectrum of the interacting porphyrins, which is strongly red-shifted compared to the free porphyrin absorption. In addition a quasi-complete quenching of the porphyrin fluorescence is also observed. [source] | |||||||||||||||||||