Conditional Entropy and the Rokhlin Metric on an Orthomodular Lattice with Bayessian State

The present paper deals with the study of conditional entropy and its properties in a quantum space (L,s), where L is an orthomodular lattice and s is a Bayessian state on L. First, we obtained a pseudo-metric on the family of all partitions of the couple (B,s), where B is a Boolean algebra and s is a state on B. This pseudo-metric turns out to be a metric (called the Rokhlin metric) by using a new notion of s-refinement and by identifying those partitions of (B,s) which are s-equivalent. The present theory has then been extended to the quantum space (L,s), where L is an orthomodular lattice and s is a Bayessian state on L. Applying the theory of commutators and Bell inequalities, it is shown that the couple (L,s) can be equivalently replaced by a couple (B,s ₀), where B is a Boolean algebra and s ₀ is a state on B.     

Comparison of the iterated equation of motion approach and the density matrix formalism for the quantum Rabi model

The density matrix formalism and the equation of motion approach are two semi-analytical methods that can be used to compute the non-equilibrium dynamics of correlated systems. While for a bilinear Hamiltonian both formalisms yield the exact result, for any non-bilinear Hamiltonian a truncation is necessary. Due to the fact that the commonly used truncation schemes differ for these two methods, the accuracy of the obtained results depends significantly on the chosen approach. In this paper, both formalisms are applied to the quantum Rabi model. This allows us to compare the approximate results and the exact dynamics of the system and enables us to discuss the accuracy of the approximations as well as the advantages and the disadvantages of both methods. It is shown to which extent the results fulfill physical requirements for the observables and which properties of the methods lead to unphysical results.     

Surface and transport studies on La0.7Ba0.3MnO3:SnO2 bilayer

We report on study of morphology, optical contrast and transport characteristics of La_0.7Ba_0.3MnO₃ (LBMO) manganite thin films bilayered with SnO₂ on Si (0 0 1) substrate, synthesized using pulsed laser deposition system. X-ray diffraction study reveals that both LBMO and SnO₂ show polycrystalline growth over the substrate. Atomic force microscopy shows interesting pyramidal structures of LBMO of size ∼2 μm × 1 μm × 0.1 μm. On the other hand, SnO₂ grows in the form of close packed cylindrical clusters of ∼200 nm radius. Near-field optical microscopy (NSOM) study using 532 nm laser reveal that optical NSOM output intensity in LBMO is four times less than SnO₂ signal. Transport characterizations show that this bilayer configuration exhibit non-linear current-voltage characteristics from 300 upto 50 K. The nature becomes linear below this temperature. The results project the system as a promising candidate in non-conventional device category in the area of spintronics.     

Green synthesis of silver nanoparticles using Thymus kotschyanus extract and evaluation of their antioxidant,antibacterial and cytotoxic effects

Present study used ecofriendly, cost efficient and easy method for synthesis of silver nanoparticles (Ag NPs) at the room temperature by Thymus Kotschyanus extract as reducing and capping agent. Various analytical technique including UV–Vis absorption spectroscopy determined presence of Ag NPs in the solution, the functional groups of Thymus Kotschyanus extract in the reduction and capping process of Ag NPs are approved by FT‐IR, crystallinity with the fcc plane approved from the X‐ray diffraction (XRD) pattern, energy dispersive spectroscopy (EDS) determined existence of elements in the sample, surface morphology, diverse shapes and size of present Ag NPs were showed by using scanning electron microscopy (SEM), atomic force microscopy (AFM) and high resolution transmission electron microscopy (HRTEM). Beginning and end destroy temperature of present silver nanoparticles were determined by thermal gravimetric spectroscopy (TGA). In addition, antibacterial, antioxidant and cytotoxicity properties of Ag NPs were studied. Agar disk and agar well diffusion are the methods to determined antibacterial properties of synthesized Ag NPs. Also MIC (Minimum Inhibitory Concentration) and MBC (Minimum Bactericidal Concentration) were recognized by macro broth dilution assay. DPPH free radical scavenging assay was used for antioxidant property and compare to butylated hydroxytoluene (BHT) as standard antioxidant that showed high antioxidant activity more than BHT. Synthesized Ag NPs have great cell viability in a dose depended manner and demonstrate that this method for synthesis silver nanoparticles provided nontoxic. The average diameter of synthesized Ag NPs was about 50–60 nm.     

Chemistry of bicyclic [1,3,4]thiadiazole 5-5 systems containing ring-junction nitrogen

This review provides a survey of the advances in the methods of formation and chemical reactivity of bicyclic [1,3,4]thiadiazole 5-5 systems containing ring-junction nitrogen over the period from 1989 to the beginning of 2017.     

Effect of calcination temperature on the properties of industrial V2O5-TiO2 (anatase) catalysts in methanol oxidation

The properties of the catalysts for partial oxidation of o-xylene depend on the structure of the supported vanadium sites. The structure itself is strongly dependent on the calcination temperature of the catalyst at which thermal deposition of the metal oxide on the oxide support takes place. We have investigated the effect of calcination temperature on the activity and selectivity of industrial V₂O₅-TiO₂ (anatase) supported catalysts designed for partial oxidation of o-xylene in their application to methanol oxidation.This revised version was published online in December 2005 with corrections to the Cover Date.     

Precise molecular shape control of linear and branched strips with chirality-assisted synthesis

ABSTRACT

This account describes the latest developments in the field of chirality-assisted synthesis (CAS). CAS has emerged as a versatile method to control the shapes of π-conjugated macromolecules and supramolecular assemblies. With CAS, the sequence and chirality of the monomeric building blocks dictates the shape and functions of the resulting macromolecules in a programmable fashion. Supramolecular materials with special functions, e.g. the ability to encapsulate macrocycles, can be created with CAS. CAS has been utilized to synthesize a variety of shape-defined nanoscale structures, including polyaromatic strips, helices, molecular claws, and very large hydrogen-bonded closed-shell capsules. Applications, challenges, and future directions of the growing CAS field are discussed in light of the unique shape-control abilities CAS has to offer.     

A new disposable biosensor platform: carbon nanotube/poly(o-toluidine) nanocomposite for direct biosensing of urea

The development of new techniques for rapid and continuous monitoring of urea in biomedical and clinical analysis is very important. Thus, conductive polymer-supported carbon nanotube as an effective electrochemical biosensing platform for direct detection of urea in blood samples was designed. For the assay optimization, several conductive polymers were synthesized and tested as electrode modifiers; among the tested polymers, poly-o-toluidine (PoT) showed the highest electrochemical signals. However, after the enzyme immobilization, direct bioelectrochemical signals were not obtained when the PoT was used alone. Due to the lower electrocatalytic feature of PoT, integration of carbon nanotube, to form a composite with the PoT, was exploited to enable the direct electron transfer. Successfully, using the hybrid, the catalytic activity of the immobilized urease enzyme was retained. Consequently, a sensitive and specific chronoamperometric signals were achieved after the bioassay optimization. Eventually, a standard calibration curve for urea determination was obtained. A linear range was found from 0.1 to 11 mM with the limit of detection of 0.03 mM. Successfully, several blood samples were analyzed and urea level was correlated with the reference analytical method.

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Graphical abstract Scheme 1: Schematic representation of screen-printed electrode-modified urease biosensors. Three-layer functionalized surface (multi-walled carbon nanotube/poly(o-toluidine) nanocomposite, with glutaraldehyde (cross-linker and urease-immobilized enzyme), was designed for urea biosensors.

     

Glycosidases in plant tissues of some brassicaceae screening of different cruciferous plants for glycosidases production

Glycosidases namely myrosinase and β-amylase, have been isolated fromBrassicaceae. These enzymes were identified and estimated by the rate of glucose and maltose formation from sinigrin (thioglucosinolate) and amylose (polysaccharides) hydrolysis, respectively. Their activities (U/g dry tissues) varied with the different species of the plant and with the different parts of their tissues. Generally, they were higher in the germinated seeds (3.3-8.0 times) than in powdered or defatted powdered dry seeds. The best amylase and myrosinase extracting solution for radish and white mustard germinated seeds was distilled water, and for turnip germinated seeds, it was 0.1M phosphate buffer, pH 6.0. In the light, the optimum germination temperature for amylase production or activation by radish and white mustard seeds was 25°C, and for turnip seeds, it was 30°C, whereas for myrosinase production or activation by radish and turnip, 25–27°C was the optimum temperature. The highest myrosinase activities in black mustard and radish defatted dry seeds were obtained by extraction with 1% NaCl at 272/30°C and distilled water at 25–27°C, after an incubation period of 4–6 h. Comparative studies indicated that fresh radish roots were the most potent amylase and myrosinase producers compared with radish leaves or roots, stems, and leaves of turnip and cabbage. Amylase and myrosinase were partially purified from water extracts of fresh radish roots by optimum precipitation with ammonium sulfate (100%). Some physicochemical properties were studied.     

Biodiesel Production by Single and Mixed Immobilized Lipases Using Waste Cooking Oil

Biodiesel is one of the important biofuels as an alternative to petroleum-based diesel fuels. In the current study, enzymatic transesterification reaction was carried out for the production of biodiesel from waste cooking oil (WCO) and experimental conditions were optimized, in order to reach maximum biodiesel yield. Bacillus stearothermophilus and Staphylococcus aureus lipase enzymes were individually immobilized on CaCO₃ to be used as environmentally friendly catalysts for biodiesel production. The immobilized lipases exhibited better stability than free ones and were almost fully active after 60 days of storage at 4 °C. A significant biodiesel yield of 97.66 ± 0.57% was achieved without any pre-treatment and at 1:6 oil/methanol molar ratio, 1% of the enzyme mixture (a 1:1 ratio mixture of both lipase), 1% water content, after 24 h at 55 °C reaction temperature. The biocatalysts retained 93% of their initial activities after six cycles. The fuel and chemical properties such as the cloud point, viscosity at 40 °C and density at 15 °C of the produced biodiesel complied with international specifications (EN 14214) and, therefore, were comparable to those of other diesels/biodiesels. Interestingly, the resulting biodiesel revealed a linolenic methyl ester content of 0.55 ± 0.02% and an ester content of 97.7 ± 0.21% which is in good agreement with EN14214 requirements. Overall, using mixed CaCO₃-immobilized lipases to obtain an environmentally friendly biodiesel from WCO is a promising and effective alternative for biodiesel production catalysis.