Robust preparation and manipulation of protected qubits using time-varying Hamiltonians

We show that it is possible to initialize and manipulate in a deterministic manner protected qubits using time-varying Hamiltonians. Taking advantage of the symmetries of the system, we predict the effect of the noise during the initialization and manipulation. These predictions are in good agreement with numerical simulations. Our study shows that the topological protection remains efficient under realistic experimental conditions.     

Structure of the Particle Population for a Branching Random Walk with a Critical Reproduction Law

We consider a continuous-time symmetric branching random walk on the d-dimensional lattice, d ≥?1, and assume that at the initial moment there is one particle at every lattice point. Moreover, we assume that the underlying random walk has a finite variance of jumps and the reproduction law is described by a continuous-time Markov branching process (a continuous-time analog of a Bienamye-Galton-Watson process) at every lattice point. We study the structure of the particle subpopulation generated by the initial particle situated at a lattice point x. We replay why vanishing of the majority of subpopulations does not affect the convergence to the steady state and leads to clusterization for lattice dimensions d =?1 and d =?2.

     

‘Clickable’ cyclopentadienyl iron carbonyl complexes for bioorthogonal conjugation of mid‐infrared labels to a model protein and PAMAM dendrimer

Owing to the intrinsic limitations of the conventional bioconjugation methods involving native nucleophilic functions of proteins, we sought to develop alternative approaches to introduce metallocarbonyl infrared labels onto proteins on the basis of the [3 + 2] dipolar azide‐alkyne cycloaddition (AAC). To this end, two cyclopentadienyl iron dicarbonyl (Fp) complexes carrying a terminal or a strained alkyne handle were synthesized. Their reactivity was examined towards a model protein and poly (amidoamine) (PAMAM) dendrimer, both carrying azido groups. While the copper (I)‐catalysed azide‐alkyne cycloaddition (CuAAC) proceeded smoothly with the terminal alkyne metallocarbonyl derivative, labelling by strain‐promoted azide‐alkyne cycloaddition (SPAAC) was less successful in terms of final coupling ratios. Infrared spectral characterization of the bioconjugates showed the presence of two bands in the 2000 cm^?1 region, owing to the stretching vibration modes of the carbonyl ligands of the Fp entities.     

Bioinspired benzoxanthene lignans as a new class of antimycotic agents: synthesis and Candida spp. growth inhibition

Abstract

In this work we synthetized the bioinspired benzoxanthene lignans (BXLs) 3, 14–22, and the phenazine derivative 23 as potential antimycotic agents. MICs and MFCs against Candida strains were determined. In a preliminary screening, compounds 3, 15, 20, 21, 22 were substantially inactive. Compounds 14 and 17 showed antifungal activity, being able to inhibit the growth of the majority of Candida strains with MIC values in the range 4.6–19.2?µM (14) and 26.0–104.3?µM (17); for three strains, the MICs were lower than those obtained using the antimycotic drug fluconazole. The three BXLs 18, 19 and 23 showed some MIC values lower than that of fluconazole; 18 was also active against two non-albicans Candida strains resistant to fluconazole. Phenazine 23, although active only against one strain (MIC?=?1.3?µM), was one order of magnitude more potent than fluconazole. All the BXLs were fungicidal.     

Efficient BOP-mediated synthesis of fulgimides

A mild and efficient method for the synthesis of fulgimides is presented in which the peptide coupling reagent BOP is employed for dehydratation of fulgenic acid monoamides (succinamic acids). The disclosed method proved to be superior to those described in the literature.     

Immunopharmacological Properties of Methacrylic Acid Polymers as Potential Polymeric Carrier Constituents of Anticancer Drugs

Cytostatic chemotherapeutics provide a classical means to treat cancer, but conventional treatments have not increased in efficacy in the past years, warranting a search for new approaches to therapy. The aim of the study was, therefore, to obtain methacrylic acid (MAA) (co)polymers and to study their immunopharmacological properties. 4-Cyano-4-[(dodecylsulfanylthiocarbonyl)sulfanyl] pentanoic acid (CDSPA) and 2-cyano-2-propyl dodecyl trithiocarbonate (CPDT) were used as reversible chain transfer agents. Experiments were carried out in Wistar rats. The MTT assay was used to evaluate the cytotoxic effect of the polymeric systems on peritoneal macrophages. An experimental tumor model was obtained by grafting RMK-1 breast cancer cells. Serum cytokine levels of tumor-bearing rats were analyzed. The chain transfer agents employed in classical radical polymerization substantially reduced the molecular weight of the resulting polymers, but a narrow molecular weight distribution was achieved only with CDSPA and high CPDT concentrations. Toxicity was not observed when incubating peritoneal macrophages with polymeric systems. In tumor-bearing rats, the IL-10 concentration was 1.7 times higher and the IL-17 concentration was less than half that of intact rats. Polymeric systems decreased the IL-10 concentration and normalized the IL-17 concentration in tumor-bearing rats. The maximum effect was observed for a MAA homopolymer with a high molecular weight. The anion-active polymers proposed as carrier constituents are promising for further studies and designs of carrier constituents of drug derivatives.