Different Types Of Complexes Research Articles

Chimeric Protein Complexes in Hybrid Species Generate Novel Phenotypes

Hybridization between species is an important mechanism for the origin of novel lineages and adaptation to new environments. Increased allelic variation and modification of the transcriptional network are the two recognized forces currently deemed to be responsible for the phenotypic properties seen in hybrids. However, since the majority of the biological functions in a cell are carried out by protein complexes, inter-specific protein assemblies therefore represent another important source of natural variation upon which evolutionary forces can act. Here we studied the composition of six protein complexes in two different Saccharomyces “sensu stricto” hybrids, to understand whether chimeric interactions can be freely formed in the cell in spite of species-specific co-evolutionary forces, and whether the different types of complexes cause a change in hybrid fitness. The protein assemblies were isolated from the hybrids via affinity chromatography and identified via mass spectrometry. We found evidence of spontaneous chimericity for four of the six protein assemblies tested and we showed that different types of complexes can cause a variety of phenotypes in selected environments. In the case of TRP2/TRP3 complex, the effect of such chimeric formation resulted in the fitness advantage of the hybrid in an environment lacking tryptophan, while only one type of parental combination of the MBF complex allowed the hybrid to grow under respiratory conditions. These phenotypes were dependent on both genetic and environmental backgrounds. This study provides empirical evidence that chimeric protein complexes can freely assemble in cells and reveals a new mechanism to generate phenotypic novelty and plasticity in hybrids to complement the genomic innovation resulting from gene duplication. The ability to exchange orthologous members has also important implications for the adaptation and subsequent genome evolution of the hybrids in terms of pattern of gene loss.

Measurement of Design Complexity of Different types of Inheritance using Cohesion Metrics

Main aim of Software Engineering is to increase quality and maintain Software Product. Inheritance reflects the degree of reusability of existing classes and reuse increases productivity. Most Cohesion Metric tool do not consider inherited elements while measuring cohesion but we can measure design quality by including the concept of inheritance in Cohesion metrics. In this paper values of all cohesion metrics (LCOM1, LCOM2, LCOM3, LCOM4, LCOM5, CO, TCC and LCC) is calculated including the concept of inheritance for Single, Multiple, Multilevel and Hierarchical Inheritance and compare results to determine design complexity of various types of Inheritances.

Competitive interaction between soil-derived humic acid and phosphate on goethite

In order to better understand the influence and mechanism of soil-derived humic acid (SHA) on adsorption of P onto particles in soils, the amounts of PO4 adsorbed by synthetic goethite (α-FeOOH) were determined at different concentrations of SHA, pH, ionic strength and order of addition of adsorbents. Addition of SHA can significantly reduce the amount of PO4 adsorption as much as 27.8%. Both generated electrostatic field and competition for adsorption sites were responsible for the mechanism by which SHA inhibited adsorption of PO4 by goethite. This conclusion was supported by measurement of total organic C (TOC), infrared spectral features and Zeta potential. Adsorption of PO4 onto goethite was inversely proportional to pH. Order of addition of PO4 and SHA can influence adsorption of PO4 as follows: prior addition of PO4⩾simultaneous addition>prior addition of SHA. Iron and SHA apparently form complexes due to prior addition of SHA. Observations made during this study emphasized that PO4 forms different types of complexes on the surface of goethite at different pH, which dominated the interaction of SHA and PO4 adsorption on goethite. Based on these observations, the possible modes of SHA inhibition of PO4 adsorption on goethite were proposed.

How are hydrogen bonds modified by metal binding?

We have used density functional theory calculations to investigate how the hydrogen-bond strength is modified when a ligand is bound to a metal using over 60 model systems involving six metals and eight ligands frequently encountered in metalloproteins. We study how the hydrogen-bond geometry and energy vary with the nature of metal, the oxidation state, the coordination number, the ligand involved in the hydrogen bond, other first-sphere ligands, and different hydrogen-bond probe molecules. The results show that, in general, the hydrogen-bond strength is increased for neutral ligands and decreased for negatively charged ligands. The size of the effect is mainly determined by the net charge of the metal complex, and all effects are typically decreased when the model is solvated. In water solution, the hydrogen-bond strength can increase by up to 37kJ/mol for neutral ligands, and that of negatively charged ligands can increase (for complexes with a negative net charge) or decrease (for positively charged complexes). If the net charge of the complex does not change, there is normally little difference between different metals or different types of complexes. The only exception is observed for sulphur-containing ligands (Met and Cys) and if the ligand is redox-active (e.g. high-valence Fe-O complexes).

Reaction of [VO(OPr)3] with hexamethyldisylthiane in the presence of β-diketones

The reaction of [VO(OPr)3] (Pr is n-propyl) with hexamethyldisylthiane Me3SiSSiMe3 in the presence of β-diketones (acetylacetone (HAcac), hexafluoroacetylacetone (Hfac), and dipivaloylmethane (Dpm)), is studied. In all cases, vanadium(IV) and vanadium(III) β-diketonate complexes of different types are formed. New crystalline modification [V(Acac)3] is obtained in the reaction with HAcac. The mixedligand vanadium(III) complex of the composition [V2(Hfac)2(μ-OPr)]2 is formed with Hfac. In the presence of Dpm, the known vanadium(IV) complex [V2O2(Dpm)2(μ-OPr)2] is obtained in which two vanadyl groups VO2+ are linked by two bridging propoxy groups. The structures of all products are determined by X-ray diffraction analysis.

Characterization of acetylacetonato carbonyl diphenyl-2-pyridylphosphine rhodium(I): Comparison with other carbonyl complexes

Different rhodium(I)/(III) diphenyl-2-pyridylphosphine complexes were isolated and successfully characterized. The [Rh(acac)(CO)(DPP)] (DPP=diphenyl-2-pyridylphosphine) complex crystallizes in the P1¯ space group with four molecules per unit cell. The results clearly show that the differences between the two independent molecules are mainly centered around the orientation of the pyridyl ring within the two square planer molecules. The results also indicate that the phosphine ligands act as monodentate ligands in both molecules, with Rh–P and Rh–CO bond distances of 2.243(1); 2.235(1) and 1.791(4); 1.776(4)Å respectively. A comparison of the ν(CO) stretching frequencies of a relatively large number of rhodium complexes indicated little overlap between the ν(CO) of different types of complexes (e.g. Rh(I) vs Rh(III)) and relatively small standard deviations within each type of complex. DFT calculations were used to determine the preferred pyridyl ring orientation. These calculations indicated that at least 12 areas of minimum energy, which exists as broad, low energy wells, are theoretically suitable for DPP group orientation within this kind of structure.

Specific site binding of metal ions on the intramolecular charge transfer fluorophore in micelles

The binding interactions of Cu(2+), an essential trace metal ion, and Cd(2+), a deleterious metal ion, with 2-(4'-N,N-dimethylaminophenyl)oxazolo[4,5-b]pyridine (DMAPOP) were studied in acetonitrile and sodium dodecyl sulphate (SDS). The studies show that the surfactant can formulate the metal ions to bind at a specific binding site. In acetonitrile, the Cu(2+) binds at the dimethylamino nitrogen and pyridine nitrogen to form two different types of complexes with DMAPOP. On the other hand, Cd(2+) coordinates through the dimethylamino nitrogen and oxazole nitrogen to form two different types of complexes with DMAPOP in acetonitrile. But SDS effectively controls the binding site and both metal ions bind at the same ring nitrogen in SDS. The binding affinities of both metal ions with DMAPOP vary with the concentration of SDS.

Efficient Approach for Knowledge Management Using Deep Web Information Retrieval System

Along with the development of network technology, web information are rapidly growing, and the way of information storage is gradually changed from the html to the database, thus web information can be divided into the surface web and deep web. Deep web is a concept corresponding to the surface web. It means from ordinary search engine that is difficult to discover the information content of a web page. The traditional crawler only crawl the content on the surface of a web, which makes the current traditional search engine, did not retrieve deep web data. Deep web compared with surface web has the advantage of large volume, high quality, theme single-minded, good structured. In view of several advantages, the establishment of deep web data integration system is becoming a research hotspot. The deep web query interface is the only entrance of the background database, so how to determine which web form is the query interface is important to the deep web information access. However, because the page proportion on the internet which contains querying interface is very small, using the traditional breadth-first strategy and keyword filtering method to crawl, it will download a lot of unrelated pages, spend a lot of resources, we need a way to efficiently find and collect the query interfaces through deep web crawling strategy. We proposed novel query planning approach, for executing different types of complex attribute through queries over multiple inter-dependent deep web data sources. increase accelerate query searching based on attribute selection, execution and propose optimization techniques, including query plan merging and grouping optimization. Keywords: Novel query planning approach, Deep web, Semantic Deep Web, Ontologies, attribute.

Tuning stoichiometry and supramolecular assembly in perfluorinated indazolato coinage metal complexes

The reaction of 3-pentafluoroethyl-4,5,6,7-tetrafluoro-1-H-indazole [3-(C2F5)IndF4]H with Ag2O or [Cu(CH3CN)4]BF4 leads to the formation of two different types of complexes: a trinuclear {[3-(C2F5)IndF4]Ag}3 complex (1) in the case of silver, and an unprecedented type of pentanuclear complex [Et3NH]{Cu5[3-(C2F5)IndF4]6} (2) in the case of copper. When crystallised from Et2O, appears as a dimer with d(10)-d(10) interactions. When crystallized from toluene, affords the [(toluene)(1)(toluene)] adduct, testifying to its strong π-acid properties. The formation and the aggregation pattern of 1 and 2 can be traced to the extended aromaticity and high electron withdrawing properties of the perfluorinated [3-(C2F5)IndF4](-) indazolate.

Managing temporal misfits in institutional environments

PurposeThe aim of this paper is to conceptualize time as an important dimension of institutions and, more specifically, to develop the analysis of institutions, time, and temporal misfits. The paper explores these matters in the context of an inter‐institutional project where actors, who represent different organizational fields and respond to different institutional requirements with regards to time and timing, need to collaborate.Design/methodology/approachThe paper centers on three critical incidents taken from a study of a large‐scale telecom project in Norway. The paper is based on an analysis of public documents and 35 interviews with key stakeholders and managers in the focal project.FindingsThis research shows that temporal misfits are a critical, yet understudied, element of project organizing. The paper suggests and discusses three primary measures – detecting, correcting, and escaping – that project management makes use of to resolve temporal misfits among the actors involved. To advance the analysis of problems facing projects in institutionally‐bounded settings, the paper proposes a typology of temporal misfits (phase and tempo) and different types of complexity (analyzable and systemic).Practical implicationsAlthough purposeful in many instances, especially in collaborations across institutional boundaries, timing norms may cause profound organizational problems due to temporal misfits among the actors involved. The paper argues that project managers need to identify and be prepared for such organizational problem by being equipped with a repertoire of resolution strategies to handle them. New concepts and approaches are needed to identify and deal with temporal misfits among important stakeholders in projects.Originality/valueA number of previous studies on project organizing have emphasized the critical aspects of studying institutions and time; but to date, no comprehensive efforts have been made to combine these ideas in empirical investigations. This study emphasizes the criticality of timing norms and temporal misfits to enhance our understanding of the linkages between projects, institutions, and time.

Regulation of Protein-Protein Binding through the Coupling Between Phosphorylation and Intrinsic Disorder

Phosphorylation offers a dynamic way to regulate protein activity, subcellular localization, and stability. At the same time phosphorylation sites are often located in the intrinsically disordered regions. We studied the effect of phosphorylation on protein binding for different types of complexes from human proteome. We estimated the effect of phosphorylation on complex stability and found that the majority of complexes do not show significant stability differences upon phosphorylation or de-phosphorylation. However, we also found that phosphorylation sites tend to be located on binding interfaces, may orthosterically modulate the strength of interactions and for about one-third of all complexes cause relatively large changes in binding energy. All this suggests that processes of phosphorylation, binding and disorder-to-order transitions might be tightly coupled with each other. Indeed we showed that there is significant association between phosphorylation, disorder and binding for serine and threonine residues in human. However, tyrosine phosphorylation might not be necessarily associated with binding through disorder-to-order transitions and is often observed in ordered regions which are not disordered in unbound state. We suggest possible mechanisms of how phosphorylation might regulate protein-protein binding via intrinsic disorder, for example, phosphorylation in disordered regions may prevent disorder-to-order transition and subsequent protein-protein binding.

Determining similarity in histological images using graph-theoretic description and matching methods for content-based image retrieval in medical diagnostics

BackgroundComputer-based analysis of digitalized histological images has been gaining increasing attention, due to their extensive use in research and routine practice. The article aims to contribute towards the description and retrieval of histological images by employing a structural method using graphs. Due to their expressive ability, graphs are considered as a powerful and versatile representation formalism and have obtained a growing consideration especially by the image processing and computer vision community.MethodsThe article describes a novel method for determining similarity between histological images through graph-theoretic description and matching, for the purpose of content-based retrieval. A higher order (region-based) graph-based representation of breast biopsy images has been attained and a tree-search based inexact graph matching technique has been employed that facilitates the automatic retrieval of images structurally similar to a given image from large databases.ResultsThe results obtained and evaluation performed demonstrate the effectiveness and superiority of graph-based image retrieval over a common histogram-based technique. The employed graph matching complexity has been reduced compared to the state-of-the-art optimal inexact matching methods by applying a pre-requisite criterion for matching of nodes and a sophisticated design of the estimation function, especially the prognosis function.ConclusionThe proposed method is suitable for the retrieval of similar histological images, as suggested by the experimental and evaluation results obtained in the study. It is intended for the use in Content Based Image Retrieval (CBIR)-requiring applications in the areas of medical diagnostics and research, and can also be generalized for retrieval of different types of complex images.Virtual SlidesThe virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1224798882787923.

Quantum-chemical study on adenine nitrosonium complexes

Adenine complexes with nitrosonium ion have been studied by the RI-MP2/L1 quantum-chemical method. Addition of nitrosonium ion to adenine tautomers produces a set of nitrosonium complexes of different types (1η–3η). n-Complexes involving NO+ coordination to nitrogen atoms are more energetically favorable than π-complexes. The global minimum on the potential energy surface is occupied by the complex of 7H-adenine tautomer with nitrosonium ion coordinated at the N3 atom.

The impact of complexity and managerial diseconomies on hierarchical governance

Based on data from Chilean construction projects, we evaluate how the boundary choice of a focal activity is affected by the number of activities integrated elsewhere in a project and by the level of “between complexity” and “within complexity” of those activities. Our results show that managerial diseconomies of scale, which arise when contractors integrate more activities, and the different types of complexity, affect the relative advantages of hierarchical governance. In a novel result, we also show that interactions between the number of integrated activities and the types of complexity affect the relative merits of hierarchical governance to handle an activity, meaning that complexity and the extent of a project's integration are systematically intertwined in the explanation of boundary choices. Our findings indicate a need for research on interdependencies between different boundary choices and suggest that the evaluation of these interdependencies should consider the complexity of activities.

Star Polymers: An Overview

This review article describes the synthesis, properties and some applications of star-shaped polymers. The arms constituted of homo- or co-polymers of different polymers are also reviewed. Methods of synthesis of various types of star-shaped polymers, including “arm first” and “core first” procedures, is given as an introduction along with some details. Then, the synthesis of star polymers (including miktoarm stars) with strictly defined as well as with varying number of arms and having cores formed from small and/or large molecules: branched, cross-linked, etc., is described. Interest in star-shaped and branched systems based on poly (ethylene oxide) (PEO) is mainly motivated by their potential applications in the biomedical and pharmaceutical areas. The properties and applications of PEO stars are also reported, such as drug carriers, surface modifiers, hydrogels, components of membranes, and also have some biomedical applications. Their potential applications as components of different types of complexes, hydrogels, networks, and ultrathin coatings are indicated.

The influence of particular chromosome regions of Triticum timopheevii on the formation of resistance to diseases and quantitative traits in common wheat

Evaluation of the influence of Triticum timopheevii Zhuk. introgression fragments (2n = 28, AtAtGG) and their combinations on resistance to leaf and stem rust, powdery mildew, and a number of quantitative traits in 15 introgressive lines of common wheat was conducted. Analysis of introgressive lines by molecular genetic and cytological methods showed the efficiency of using a complex of different types of markers for detailed characterization of hybrid forms and detection of different translocations and substitutions. Evaluation of lines according to their resistance to fungal diseases showed that lines that contain an introgressive fragment of the 5G chromosome in their genome are completely resistant to populations of leaf rust in Western Siberia and the stem rust that is typical for Omsk oblast. Lines 3862-5 and 3862-15, which contain a fragment of the long arm of the 2G chromosome in their genome, were resistant to the population of stem rust in Western Siberia. Introgressive lines were studied for a number of quantitative traits. No negative influence of alien material on the yield and other quantitative traits was observed in all studied lines, which allows one to use them in breeding as donors of resistance to fungal diseases. In addition, the positive influence of T. timopheevii 2G chromosome fragments on the number of grains in an ear was determined.

Metformin and Biguanide Complexes of Isothiocyanatosilane

The preparation of neutral and ionic silicon–nitrogen complexes has been achieved by a single-step room temperature reaction by using isothiocyanatosilanes and metformin/biguanide ligands. These bidentate ligands coordinate to the silicon atom in a neutral as well as a deprotonated form to yield two different types of complexes. The resulting complexes have been characterized by the physical and spectroscopic techniques.

Revisit of Unusual Ruthenium(III) Dichloro Complex

](bpy = 2,2'-bipyridine) with CAN as one-electron oxidizingreagent in saturated ammonium hexafluorophosphate solu-tion. It also deserves special emphasis that Ru complexescontaining bulky anions are quite useful as precursors inpreparing different types of complexes for their goodsolubility in organic solvents.In a typical reaction, cis-[Ru

ChemInform Abstract: Detection and Structural Characterization of Oxo‐chromium(V)—Sugar Complexes by Electron Paramagnetic Resonance

AbstractReview: 108 refs.

Interactions between Iron(III)-hydroxide Polymaltose Complex and Commonly Used Drugs

Under physiological conditions, ferric ions are essentially insoluble because of the formation of polynuclear hydroxo-bridged complexes. Ferrous ions are more soluble but may produce hydroxyl radicals on reaction with hydrogen peroxide. Chelation of ferric and ferrous ions with organic ligands may prevent these undesirable reactions. Alternatively, iron(III)-hydroxide/oxide can be stabilized and solubilized by tight interactions with carbohydrates. The data presented in this work show that, because of its physicochemical properties, the iron(III)-hydroxide polymaltose complex (IPC, Maltofer) does not interact with the active ingredients of commonly used drugs such as acetylsalicylic acid (CAS 50-78-2), tetracycline hydrochloride (CAS 64-75-5), calcium hydrogen-phosphate (CAS 7757-93-9), methyl-L-dopa sesquihydrate (CAS 41372-08-1), and magnesium-L-aspartate hydrochloride (CAS 28184-71-6). In contrast, as confirmed by calculations using thermodynamic parameters, FeCl3 x 6H2O (CAS 10025-77-1) can form different types of complexes with these substances. Moreover, the data show that under aerobic conditions high concentrations of ascorbic acid (CAS 50-81-7) can lead to mobilization of iron from IPC and, thus, support the observation that orange juice slightly increases the uptake of iron from IPC.