Search results for "Metals"
showing 10 items of 2013 documents
Streptavidin-coated TiO2 surfaces are biologically inert: Protein adsorption and osteoblast adhesion studies
2011
Non-fouling TiO2 surfaces are attractive for a wide range of applications such as biosensors and medical devices, where biologically inert surfaces are needed. Typically, this is achieved by controlled surface modifications which prevent protein adsorption. For example, polyethylene glycol (PEG) or PEG-derived polymers have been widely applied to render TiO2 surfaces biologically inert. These surfaces have been further modified in order to achieve specific bio-activation. Therefore, there have been efforts to specifically functionalize TiO2 surfaces with polymers with embedded biotin motives, which can be used to couple streptavidin for further functionalization. As an alternative, here a s…
Molecular recognition in biotin-streptavidin systems and analogues at the air-water interface
1992
Abstract Specific interaction between biotin and the protein streptavidin in monolayers of synthetic lipids with biotin headgroups has been shown to lead to formation of highly ordered two-dimensional streptavidin crystals. The same behaviour is observed when using desthiobiotin as lipid headgroup which exhibits a significantly lower binding constant compared with biotin (5 × 10 13 M -1 compared with 10 15 M -1 ). This offers the possibility of detaching competetively the 2D crystalline streptavidin layer by addition of free biotin to the aqueous phase. Use of lipoic acid as lipid headgroup ( K a = 7 × 10 7 M −1 ) leads to formation of small snisotropic protein domains indicating a crystall…
Stress transfer mechanism investigation in hybrid steel trussed-concrete beams by push-out tests
2014
Abstract Results of push-out tests carried out on Hybrid Steel Trussed–Concrete Beams (HSTCBs) before and after the concrete casting are presented and interpreted. Firstly, in order to check the ability of weldings before casting, tensile tests were performed on specimens reproducing different types of welded joints. Simplified design formulae were used to predict their ultimate strength. Secondly, results obtained by push-out tests on specimen representative of the beam before and after the concrete casting are presented and discussed. Finally, simplified analytical models proposed by the current European building code were adapted to the specific typology to roughly predict the ultimate s…
FEM analysis of push-out test response of Hybrid Steel Trussed Concrete Beams (HSTCBs)
2015
Abstract Aiming to investigate the steel truss–concrete stress transfer mechanism in Hybrid Steel Trussed–Concrete Beams (HSTCBs), a three-dimensional (3D) nonlinear Finite Element (FE) model is developed. The constitutive relationship of the steel composing the plates and the rebars is modeled by means of a quadri-linear law, while the concrete behavior is defined by means of a Concrete Damaged Plasticity (CDP) model, suitable for modeling concrete and brittle materials. Two main failure mechanisms are considered, namely the tensile cracking and the compressive crushing. In order to accurately grasp the complicate dowel and bond phenomena arising at the steel–concrete interface, a 3D solid…
Biomaterials coated by dental pulp cells as substrate for neural stem cell differentiation
2011
[EN] This study is focused on the development of an in vitro hybrid system, consisting in a polymeric biomaterial covered by a dental pulp cellular stroma that acts as a scaffold offering a neurotrophic support for the subsequent survival and differentiation of neural stem Cells. In the first place, the behavior of dental pulp stroma on the polymeric biomaterial based on ethyl acrylate and hydroxy ethyl acrylate copolymer was studied. For this purpose, cells from normal human third molars were grown onto 0.5-mm-diameter biomaterial discs. After cell culture, quantification of neurotrophic factors generated by the stromal cells was performed by means of an ELISA assay. In the second place, s…
Automated electron diffraction tomography – development and applications
2019
Electron diffraction tomography, a potential method for structure analysis of nanocrystals, and, in more detail, the strategies to use automated diffraction tomography (ADT) technique are described. Examples of ADT application are discussed according to the material class.
Site Preference in Multimetallic Nanoclusters: Incorporation of Alkali Metal Ions or Copper Atoms into the Alkynyl-Protected Body-Centered Cubic Clus…
2016
The synthesis, structure, substitution chemistry, and optical properties of the gold-centered cubic monocationic cluster [Au@Ag8@Au6(C≡CtBu)12]+ are reported. The metal framework of this cluster can be described as a fragment of a body-centered cubic (bcc) lattice with the silver and gold atoms occupying the vertices and the body center of the cube, respectively. The incorporation of alkali metal atoms gave rise to [MnAg8−nAu7(C≡CtBu)12]+ clusters (n=1 for M=Na, K, Rb, Cs and n=2 for M=K, Rb), with the alkali metal ion(s) presumably occupying the vertex site(s), whereas the incorporation of copper atoms produced [CunAg8Au7−n(C≡CtBu)12]+ clusters (n=1–6), with the Cu atom(s) presumably occup…
Inhibitoren der Korrosion (9) Nachweis der Sekundärinhibitoren bei einigen Sulfoxiden, Triphenylarsinoxid und einigen Sulfoniumsalzen
1971
Die Schutzwerte von Dibenzylsulf-oxyd und strukturell verwandten Ver-bindungen sowie von Triphenylarsin-oxyd werden bestimmt. Sulfoxyde und Arsinoxyde werden (a) nach Protonierung in die kathodischen Bereiche gefuhrt und (b) nach Elektronenaufnahme in die ko-ordinationsfahigen Sekundarinhibitoren (Thioather und tert. Arsine) umgewan-delt. Die Sekundarinhibitoren ziehen entweder auf das Metall auf und unter-drucken dann die Auflosung des Eisens oder werden nicht am Metall fixiert (z. B. Diphenylsulfid) und entfalten dann keinen Schutz. Im Falle des Dibenzyl-sulfoxyds konnen ca. 90% des einge-setzten Dibenzylsulfoxyds als Dibenzyl-sulfid vom Eisen abgelost werden; 16% an unverandertem Dibenzy…
Isolation, dynamic NMR study and X-ray characterisation of a bis sulfonium zirconocene-ate dimer.
2004
The novel dimer [Cp(2)Zr[upper bond start]([minus sign in circle])S([plus sign in circle])CH(Ph)CH[double bond]C[upper bond end]PPh(2)](2), the first example of a structurally characterised sulfur-bridged binuclear zirconathiolane complex, was prepared, characterised by NMR spectroscopy and X-ray crystallography, and some aspects of its solution behaviour were studied.
Giant negative magnetoresistance in GdI2
2000
Abstract GdI 2 is a layered d 1 compound which is isostructural with and nominally isoelectronic to the superconductors 2H–TaS 2 and 2H–NbSe 2 . GdI 2 orders ferromagnetically at 276(2) K and displays large negative magnetoresistance ∼70% at 7 T close to room temperature. At 10 K the saturation magnetization is 7.33(5) μ B in good agreement with the value predicted from spin polarized band structure calculations.