Magnetooptics in Gold and Silver NanoSizes Low-Dimensional Objects

The spectra of optical absorption and of magnetic circular dichroism (MCD) have been measured in the 350–1150 nm wavelength range for a set of colloidal solutions containing Au and Ag nanoparticles. The average size of Au nanoparticles was 6 nm and having thiolate coatings with different degrees of chirality. (The average size of Ag nanoparticles was 14 nm and having citrate coatings) The form of absorption and MCD spectra suggests the dipole character of interband transitions involving the 5d–6(sp) for Au orbitals and 4d–5(sp) for Ag orbitals. The absence (within the experimental error) of the MCD spectra dependence on the coating type rules out the hypothesis on the orbital nature of the observed magnetism. We argue that the spin polarization plays the dominant role in the magnetism both for Au and Ag nanoparticles. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3534

On the Interaction of Clostridium perfringens Enterotoxin with Claudins

Clostridium perfringens causes one of the most common foodborne illnesses, which is largely mediated by the Clostridium perfringens enterotoxin (CPE). The toxin consists of two functional domains. The N-terminal region mediates the cytotoxic effect through pore formation in the plasma membrane of the mammalian host cell. The C-terminal region (cCPE) binds to the second extracellular loop of a subset of claudins. Claudin-3 and claudin-4 have been shown to be receptors for CPE with very high affinity. The toxin binds with weak affinity to claudin-1 and -2 but contribution of these weak binding claudins to CPE-mediated disease is questionable. cCPE is not cytotoxic, however, it is a potent modulator of tight junctions. This review describes recent progress in the molecular characterization of the cCPE-claudin interaction using mutagenesis, in vitro binding assays and permeation studies. The results promote the development of recombinant cCPE-proteins and CPE-based peptidomimetics to modulate tight junctions for improved drug delivery or to treat tumors overexpressing claudins

Vanninfiltrasjonsbrønner, Follobanen. Arkeologiske undersøkelser i forbindelse med etablering av vanninfiltrasjonsbrønner - Follobanen

I forbindelse med etablering av infiltrasjonsbrønner som ledd i Follobane-utbyggingen, ble det foretatt en arkeologisk overvåking og utgravning på tre forskjellige steder i og ved middelalderparken i Gamlebyen i Oslo. Feltarbeidet foregikk i perioden november 2015 til januar 2016, samt enkelte dager sommeren 2016. Brønn 2+3 (som bestod av to kummer etablert på samme sted) lå i enden av Clemens gate. Her ble det avdekket 11 nivåer med en trebrolagt vei orientert tilnærmet N-S, som ble tolket som Vestre Strete, en av hovedgatene i middelalderens Oslo. Det ble funnet en del keramikk samt andre gjenstander fra middelalderen. Det ble også avdekket noen bosetningsrester i kanten av veien, som grovt kunne avgrenses mot vest. Brønn 4 lå ved Lokomotivverkestedet like ved vannspeilet i middelalderparken, mens Brønn 5 lå ved Saxegården. Alle tiltakene i forbindelse med etablering av brønn 4 og 5 ble overvåket av arkeolog, og det ble ikke avdekket kulturlag fra middelalder ved noen av gravearbeidene eller boreundersøkelsene

On the Interaction of Clostridium perfringens Enterotoxin with Claudins

Clostridium perfringens causes one of the most common foodborne illnesses, which is largely mediated by the Clostridium perfringens enterotoxin (CPE). The toxin consists of two functional domains. The N-terminal region mediates the cytotoxic effect through pore formation in the plasma membrane of the mammalian host cell. The C-terminal region (cCPE) binds to the second extracellular loop of a subset of claudins. Claudin-3 and claudin-4 have been shown to be receptors for CPE with very high affinity. The toxin binds with weak affinity to claudin-1 and -2 but contribution of these weak binding claudins to CPE-mediated disease is questionable. cCPE is not cytotoxic, however, it is a potent modulator of tight junctions. This review describes recent progress in the molecular characterization of the cCPE-claudin interaction using mutagenesis, in vitro binding assays and permeation studies. The results promote the development of recombinant cCPE-proteins and CPE-based peptidomimetics to modulate tight junctions for improved drug delivery or to treat tumors overexpressing claudins

Mechanism of Clostridium perfringens Enterotoxin Interaction with Claudin-3/-4 Protein Suggests Structural Modifications of the Toxin to Target Specific Claudins

Claudins (Cld) are essential constituents of tight junctions. Domain I of Clostridium perfringens enterotoxin (cCPE) binds to the second extracellular loop (ECL2) of a subset of claudins, e.g. Cld3/4 and influences tight junction formation. We aimed to identify interacting interfaces and to alter claudin specificity of cCPE. Mutagenesis, binding assays, and molecular modeling were performed. Mutation-guided ECL2 docking of Cld3/4 onto the crystal structure of cCPE revealed a common orientation of the proposed ECL2 helix-turn-helix motif in the binding cavity of cCPE: residues Leu150/Leu151 of Cld3/4 bind similarly to a hydrophobic pit formed by Tyr306, Tyr310, and Tyr312 of cCPE, and Pro152/Ala153 of Cld3/4 is proposed to bind to a second pit close to Leu223, Leu254, and Leu315. However, sequence variation in ECL2 of these claudins is likely responsible for slightly different conformation in the turn region, which is in line with different cCPE interaction modes of Cld3 and Cld4. Substitutions of other so far not characterized cCPE residues lining the pocket revealed two spatially separated groups of residues (Leu223, Asp225, and Arg227 and Leu254, lle258, and Asp284), which are involved in binding to Cld3 and Cld4, albeit differently. Involvement of Asn148 of Cld3 in cCPE binding was confirmed, whereas no evidence for involvement of Lys156 or Arg157 was found. We show structure-based alteration of cCPE generating claudin binders, which interact subtype-specific preferentially either with Cld3 or with Cld4. The obtained mutants and mechanistic insights will advance the design of cCPE-based modulators to target specific claudin subtypes related either to paracellular barriers that impede drug delivery or to tumors

THE ENERGY OF HIGHLY DISPERSED ROCK COMPOSITES

The effect of the composition of silica-rock and basalt composite in a highly dispersed state on its energy characteristics has been investigat­ed. The dependences for the surface energy, the Gibbs energy and the Ha­maker constant on the system composition have been obtained

OPTIMIZATION OF BUILDING MORTAR COMPOSITION CONTAINING HIGHLY DISPERSED COMPOSITES

The influence of the highly dispersed rock components on the properties of building mortars was investigated. It was proved that it is possible to produce building mortars with the use of raw mate­rials resources from Arkhangelsk region through introducing highly dispersed composite based on basalt and silica-containing rocks. Us­ing highly dispersed composites, the efficient building mortar was de­signed