Supramolecular assembly in a Janus-type urea system

A pyrazolyl urea ligand adopts two possible conformations with the urea NH groups directed either outward or inward. Metal coordination enforces the outward conformation resulting in either anion complexation or self-association and hence extended supramolecular assemblies including a hexameric barrel that persists in solution

Hur viktigt är svarsformatet för testeffekten?

Det finns olika metoder som kan användas för att komma ihåg instuderat material. Det har visats att resultatet på ett minnestest förbättras avsevärt om man under inlärning har testats på instuderat material, jämfört med att enbart ha studerat materialet utan testning, detta kallas testeffekten. Syftet med föreliggande studie var att undersöka hur viktigt svarsformatet är för testeffekten där 38 försöksdeltagare fick studera 48 ordpar för att sedan bli testade vid två olika tillfällen (efter 5 minuter respektive 1 vecka). Svarsformatet manipulerades vid både inlärning (covert/overt) och slutlig testning, enligt teorin om transfer-appropriate processing (kongruent/inkongruent). Resultatet visade en signifikant huvudeffekt av svarsformat, sådan att overt framplockning ledde till bättre minnesprestation än covert framplockning. Kongruensen mellan svarsformaten vid inlärning respektive slutlig testning (TAP) gav inga signifikanta effekter. Möjliga förklaringar till resultatet, och de slutsatser som kan dras därav, diskuteras

re shaping the edges | the case of Bratislava

The initial reason of the sheltering of a community, which is developed in what we nowadays call a city, was the proximity to the natural resources such as the water and the quality of soil and the geomorphological relief and etc. The contemporary city seems to lack of a positive relation between the urban context and the natural landscape in which urban areas and natural landscape interact giving importance and meaning to each other. The quiet new field of landscape architecture stands to the border line between them. The transition moment between the urban and the natural environment creates different edges in the city which construct the image of the whole city. This thesis questions how these edges of the city could be transformed as to create an urban narrative of the spirit of the places and a dialogue of the city and the natural resources. It would be a dialogue within the reshaping of the urban context and specifically the reshaping of the city edges. The spirit of the place, the historical context and the existent natural characteristics are the elements that are involved to this thesis in order to answer with a design approach, the research question of this thesis. The result is a project through scales at two edges of the city: the motorway D2 and the riverfront to Danube. The large scale of the intervention focuses in a focal point of the city where Danube, Carpathians, Medieval city and a motorway coexist.FlowscapesLandscape ArchitectureArchitecture and The Built Environmen

Crystal engineering of Co(II), Ni(II), CU(II) and Zn(II) coordination complexes with imidazole derivatives as ligands

The main target of this thesis was the crystal engineering studies of transition metal complexes of CoII, NiII, CuII and ZnII with substituted imidazoles as ligands. Crystal engineering may be regarded as the solid-state branch of supramolecular chemistry. Supramolecular chemistry is one of the most popular and rapidly developing areas of experimental chemistry. It may be defined as the chemistry of weak intermolecular forces and focuses on the structure and function of chemical systems with higher complexity (supermolecules), that result from the association of two or more discrete chemical species (molecules, ions) held together by weak (and reversible) intermolecular forces (e.g. π-π interactions, hydrogen bonds, hydrophobic interactions, van der Waals forces, dipole-dipole interactions, metal-ligand coordination bonds etc). [...]Βασικός στόχος της παρούσης Διατριβής ήταν η μελέτη της κρυσταλλικής μηχανικής συμπλόκων ενώσεων των μεταβατικών μετάλλων CoII, NiII, CuII και ZnII με ιμιδαζολικά παράγωγα ως υποκαταστάτες. Η κρυσταλλική μηχανική μπορεί να θεωρηθεί ως ο κλάδος της υπερμοριακής χημείας στη στερεά κατάσταση. Η υπερμοριακή χημεία (supramolecular chemistry) είναι μια από τις πλέον δημοφιλείς και γρήγορα αναπτυσσόμενες περιοχές της πειραματικής χημείας. Χαρακτηρίζεται ως η χημεία των ασθενών διαμοριακών δυνάμεων και εστιάζει στη δομή και λειτουργία χημικών συστημάτων με υψηλότερη πολυπλοκότητα (υπερμόρια) που προκύπτουν από το συνδυασμό δύο ή περισσοτέρων διακριτών χημικών ειδών (μορίων, ιόντων) και συγκρατούνται με ασθενείς (και αντιστρεπτές) διαμοριακές δυνάμεις (π.χ. αλληλεπιδράσεις π-π, δεσμούς υδρογόνου, υδρόφοβες αλληλεπιδράσεις, δυνάμεις van der Waals, αλληλεπιδράσεις διπόλου-διπόλου, δεσμούς ένταξης μετάλλου-υποκαταστάτη κλπ). [...

Zinc(II) and Nickel(II) Benzoate Complexes from the Use of 1-methyl-4,5-diphenylimidazole

Two new complexes, [Zn(O2CPh)2(L)2]⋅2MeOH  (⋅2MeOH) and [Ni2(O2CPh))4(L)2]⋅2MeCN  (⋅2MeCN), have been synthesized and characterized by X-ray analysis in the course of an ongoing investigation of the MII/X−/L[MII=Co,Ni,Cu,Zn; X−=Cl−,Br−,I−,NCS−,NO−3,N−3,PhCO−2; L=1-methyl-4,5-diphenylimidazole] reaction system, aiming at understanding and assessing the relative strength and the way in which the intermolecular interactions control the supramolecular organization of these compounds. In the mononuclear complex ⋅2MeOH, the benzoate ion acts as a monodentate ligand resulting in a distorted tetrahedral N2O2 coordination environment. Complex ⋅2MeCN exhibits a dinuclear paddle-wheel structure; each NiII has a square pyramidal NiNO4 chromophore with four benzoate oxygens in the basal plane and the pyridine-type nitrogen atom of one ligand L at the apex. The structure of ⋅2MeOH is stabilized by intramolecular - interactions between aromatic rings of adjacent 4,5-diphenylimidazole moieties; it is a feature also evidenced in similar compounds of the type [MX2L2]

Development of a real-time PCR detection method for a FCGR2A polymorphism in the LightCycler and application in the heparin-induced thrombocytopenia syndrome

Objective: The FcγRIIa receptor is responsible for the activation of platelets by antibodies in heparin-induced thrombocytopenia (HIT). The c.497G > A polymorphism in the corresponding FCG2RA gene (H131R) has been implicated in the HIT syndrome and we aimed at its rapid and reliable determination. Design and methods: We designed a novel asymmetric real-time PCR method in the LightCycler that uses two hybridization probes and is followed by melting curve analysis. Seventy-one post-cardiac-surgery HIT Greek patients well ascertained by clinical data, immunological and functional tests (PAT, CD62P-selectin and microparticle flow cytometric detection) were studied, along with a clinically relevant group of 49 thrombocytopenic control patients and 119 healthy subjects. Results: The developed method has excellent analytical characteristics (linear and efficient amplification, precision), has wide ΔTm between the two alleles H and R (11.53 °C), and is in 100% concordance with validated controls and another commonly used screening method. The RR percentage increased from 10% in the control populations to 24% in the HIT patient group. Conclusion: The described method is technically simple, robust, fast, and accurate. A statistically significant difference was found in the comparison between the groups of HIT patients and healthy subjects [RR vs. RH+ HH, χ2 test, p = 0.01, OR (95% C.I.) 2.81 (1.21-4.68)]. The RR frequency in the Greek population was found to be the lowest among Caucasians. © 2009 The Canadian Society of Clinical Chemists

A Systematic Evaluation of the Interplay of Weak and Strong Supramolecular Interactions in a Series of Co(II) and Zn(II) Complexes Tuned by Ligand Modification

A systematic investigation on a designed series of 21 transition metal complexes has been carried out with the intention to explore and assess the relative strength and the way in which intermolecular interactions, namely, weak and strong hydrogen-bonding and π–π interactions, cooperate and direct molecular association during crystallization. The complexes were prepared using the general M^II/X^–/L or HL′ (M^II = Co^II, Zn^II; X^– = Cl^–, Br^–, I^–, NO₃^–, NO₂^–, ClO₄^–; L = 1-methyl-4,5-diphenylimidazole; and HL′ = 4,5-diphenylimidazole) reaction system and were characterized by single-crystal X-ray crystallography. Although the two ligands are structurally similar, the crystal packing organization of their complexes is markedly different. In structures with L, the 3D assembly is based only on weak C–H···X, C–H···π, and intramolecular π···π stacking interactions, whereas in those with HL′, it is the recurring N–H···X motifs that clearly dominate and guide the molecular self-assembly. The formation of such synthons has been activated by choosing appropriate anions X, acting as terminal ligands or counterions. In parallel, the conformational flexibility of the two ligands serves a dual purpose: (i) L contributes to the stabilization of complexes via intramolecular π···π stacking interactions, and (ii) HL′ facilitates the synthon formation by adopting appropriate conformations, even at the expenses of the stabilizing intramolecular π···π stacking