Differential Pulse Voltammetric Detection of Hepatitis C Virus 1a Oligonucleotide Chain by a Label‐Free Electrochemical DNA Hybridization Biosensor Using Consensus Sequence of Hepatitis C Virus 1a Probe on the Pencil Graphite Electrode

The short sequence related to hepatitis C virus (HCV1) is detected by a label‐free DNA hybridization biosensor. The sensor relies on the immobilization of a 20‐mer oligonucleotide containing 2 guanine and 11 cytosine bases denoted PHCV1 as probe on the pencil graphite electrode (PGE). The hybridization event was monitored by differential pulse voltammetry (DPV) using the guanine signal. The selectivity of the biosensor was studied using some noncomplementary oligonucleotides. Diagnostic performance of the biosensor is described and the detection limit was found to be 6.5 nM.     

Relating the CMSSM and SUGRA models with GUT-scale and super-GUT-scale supersymmetry breaking

While the constrained minimal supersymmetric standard model (CMSSM) with universal gaugino masses, m _1/2, scalar masses, m ₀, and A-terms, A ₀, defined at some high energy scale (usually taken to be the GUT scale) is motivated by general features of supergravity models, it does not carry all of the constraints imposed by minimal supergravity (mSUGRA). In particular, the CMSSM does not impose a relation between the trilinear and bilinear soft supersymmetry breaking terms, B ₀=A ₀?m ₀, nor does it impose the relation between the soft scalar masses and the gravitino mass, m ₀=m _3/2. As a consequence, tanβ is computed given values of the other CMSSM input parameters. By considering a Giudice–Masiero (GM) extension to mSUGRA, one can introduce new parameters to the Kähler potential which are associated with the Higgs sector and recover many of the standard CMSSM predictions. However, depending on the value of A ₀, one may have a gravitino or a neutralino dark matter candidate. We also consider the consequences of imposing the universality conditions above the GUT scale. This GM extension provides a natural UV completion for the CMSSM.     

Some notes on amenability and weak amenability of Lau product of Banach algebras defined by a Banach algebra morphism

Let A and B be Banach algebras and T : B → A be a continuous homomorphism. nweak amenability of the Banach algebra A ×T B(defined in Bade, W. G., Curtis, P. C., Dales, H. G.:Amenability and weak amenability for Beurling and Lipschitz algebras. Proc. London Math. Soc.,55(2), 359–377(1987)) is studied. The new version of a Banach algebra defined with a continuous homomorphism is introduced and Arens regularity and various notions of amenability of this algebra are studied.     

Hollow Zn/Co Zeolitic Imidazolate Framework (ZIF) and Yolk–Shell Metal@Zn/Co ZIF Nanostructures

Metal–organic frameworks (MOFs) feature a great possibility for a broad spectrum of applications. Hollow MOF structures with tunable porosity and multifunctionality at the nanoscale with beneficial properties are desired as hosts for catalytically active species. Herein, we demonstrate the formation of well‐defined hollow Zn/Co‐based zeolitic imidazolate frameworks (ZIFs) by use of epitaxial growth of Zn‐MOF (ZIF‐8) on preformed Co‐MOF (ZIF‐67) nanocrystals that involve in situ self‐sacrifice/excavation of the Co‐MOF. Moreover, any type of metal nanoparticles can be accommodated in Zn/Co‐ZIF shells to generate yolk–shell metal@ZIF structures. Transmission electron microscopy and tomography studies revealed the inclusion of these nanoparticles within hollow Zn/Co‐ZIF with dominance of the Zn‐MOF as shell. Our findings lead to a generalization of such hollow systems that are working effectively to other types of ZIFs.     

Detection of Human Interleukine‐2 Gene Using a Label‐Free Electrochemical DNA Hybridization Biosensor on the Basis of a Non‐Inosine Substituted Probe

The human interleukine‐2 gene (hIL‐2) is detected with a label‐free DNA hybridization biosensor using a non‐inosine substituted probe. The sensor relies on the immobilization of a 20‐mer antisense single strand oligonucleotide (chIL‐2) related to the human interleukine‐2 gene on the pencil graphite electrode (PGE) as a probe. The guanine oxidation signal was monitored using anodic differential pulse voltammetry (ADPV). The electrochemical pretreatment of the polished PGE at 1.80 V for 5 min is suggested. Then, 5 min immobilization at 0.50 V was found as the optimum condition for immobilization of the probe. The electrochemical detection of hybridization between chIL‐2 and hIL‐2 as a target was accomplished. The selectivity of the biosensor was studied using noncomplementary oligonucleotides. Diagnostic performance of the biosensor is described and the detection limit is found 36 pg/μL.     

Phthalocyanoiron complex with bridged ligands. Electronic structure of monomers and polymers

Electronic structure aspects related to the semiconducting properties of monomers and polymers of phthalocyanoiron with bidentate bridging ligands, PcFe–L₂ and ? [PcFe(L)]_n, have been investigated from density functional calculations [L = pyrazine, triazine, tetrazine, pyridine, 4,4′‐bipyridine, bipyridyacetylene, and bis(4‐pyridyl)bencene]. The following relevant results have been obtained: (a) an energy analysis in terms of electrostatic interaction, Pauli repulsion, and occupied/virtual orbital interactions show that the Pauli repulsion is the origin that the axial ligands (L) prefer be located toward the aza positions of the macrocycle, and (b) the intrinsic semiconducting properties depend of the frontier band. The valence band is composed largely by the transition metal d_xy orbital. The conduction band is composed of a mixture between the metallomacrocycle and bridged ligand orbitals for systems formed by pyrazine, bipyridine, and bipyridyacetylene. However, this composition is different when the ligands are triazine and tetrazine, which show a band composed of π* orbitals. These systems are predicted to show the higher conductivity within the series, in agreement with experimental results. © 2001 John Wiley & Sons, Inc. Int J Quant Chem 82: 170–181, 2001     

Excited-State Dynamics of [Ru(bpy)3]2+ Thin Films on Sensitized TiO2 and ZrO2

The excited state dynamics of Tris(2,2′-bipyridine)ruthenium(II) hexafluorophosphate, [Ru(bpy)₃(PF₆)₂], was investigated on the surface of bare and sensitized TiO₂ and ZrO₂ films. The organic dyes LEG4 and MKA253 were selected as sensitizers. A Stern–Volmer plot of LEG4-sensitized TiO₂ substrates with a spin-coated [Ru(bpy)₃(PF₆)₂] layer on top shows considerable quenching of the emission of the latter. Interestingly, time-resolved emission spectroscopy reveals the presence of a fast-decay time component (25±5 ns), which is absent when the anatase TiO₂ semiconductor is replaced by ZrO₂. It should be specified that the positive redox potential of the ruthenium complex prevents electron transfer from the [Ru(bpy)₃(PF₆)₂] ground state into the oxidized sensitizer. Therefore, we speculate that the fast-decay time component observed stems from excited-state electron transfer from [Ru(bpy)₃(PF₆)₂] to the oxidized sensitizer. Solid-state dye sensitized solar cells (ssDSSCs) employing MKA253 and LEG4 dyes, with [Ru(bpy)₃(PF₆)₂] as a hole-transporting material (HTM), exhibit 1.2 % and 1.1 % power conversion efficiency, respectively. This result illustrates the possibility of the hypothesized excited-state electron transfer.