Polyaniline biosensor for choline determination

Choline oxidase has been immobilized inside nanostructured polyaniline layers of a controlled porosity and a micrometer or nanometer thickness to form a choline sensor: polyaniline-choline oxidase (PChO) biosensor. Electrochemical techniques were used either, to prepare polyaniline films of a controlled thickness and to immobilize the enzyme molecules. The electrical response of a PChO sensor depends on choline concentration and its sensitivity reaches a value of 5 μA/mM in the amperometric mode and of 10 mV/mM in the potentiometric mode of measurements. The current response measured at a constant potential of +0.4 V is linear vs. choline concentration. No interference with ascorbic acid has been found. The storage stability is very satisfied: the sensors examined did not change essentially their electrical response even after a month of storage.     

On Orthogonal Latin <Emphasis Type="Italic">p</Emphasis>-Dimensional Cubes

We give a construction of p orthogonal Latin p-dimensional cubes (or Latin hypercubes) of order n for every natural number n ≠ 2, 6 and p ≥ 2. Our result generalizes the well known result about orthogonal Latin squares published in 1960 by R. C. Bose, S. S. Shikhande and E. T. Parker.     

Structural Aspect of CuCN Catalytic Cyclodimerization of N‐Allylquinolinium Halides

By a reaction between the corresponding [N‐allylquinolinium]X (X = Cl, Br, I) and CuCN in a methanolic medium crystals of [C₂₄H₂₁N₂][CuCl_1.35Br_0.65] ( 1 ), [C₂₄H₂₁N₂][CuBr₂] ( 2 ) and [C₂₄H₂₁N₂]I ( 3 ) have been obtained and characterized structurally by X‐ray (at 100 K). Isostructural complexes 1 and 2 crystallize in monoclinic space group P2₁/n, Z = 4: 1 a = 13.193(4), b = 19.185(5), c = 8.429(3), β = 104.85(3)°, V = 2062(1) ų, R = 0.051 for 3359 reflections; 2 a = 13.373(4), b = 19.104(6), c = 8.544(3) Å, β = 104.58(3)°, V = 2112(1) ų, R = 0.057 for 3297 reflections. Compound 3 crystallizes in monoclinic system, space group P2₁/n, Z = 4, a = 8.889(2), b = 16.842(3), c = 13.294(3) Å, β = 104.71(3)° V = 1925(1) ų, R = 0.034 for 4042 reflections. The same cation [C₂₄H₂₁N₂]⁺ in the compound 1 – 3 appeared as a product of N‐allylquinolinium catalytic cyclodimerization. Neither N‐allyl nor C‐vinyl groups participate in Cu^I π‐coordination in the structures of 1 and 2 , therefore [CuX₂]^? anions can possess a linear form.     

Ground‐State Chemical Reactivity under Vibrational Coupling to the Vacuum Electromagnetic Field

The ground‐state deprotection of a simple alkynylsilane is studied under vibrational strong coupling to the zero‐point fluctuations, or vacuum electromagnetic field, of a resonant IR microfluidic cavity. The reaction rate decreased by a factor of up to 5.5 when the Si?C vibrational stretching modes of the reactant were strongly coupled. The relative change in the reaction rate under strong coupling depends on the Rabi splitting energy. Product analysis by GC‐MS confirmed the kinetic results. Temperature dependence shows that the activation enthalpy and entropy change significantly, suggesting that the transition state is modified from an associative to a dissociative type. These findings show that vibrational strong coupling provides a powerful approach for modifying and controlling chemical landscapes and for understanding reaction mechanisms.     

Phase Shift Adjustment for Harmonic Balance Method Applied to Vibro-impact Systems

This work addresses the phase shift adjustment between the external forcing and the responses for strongly non-linear dynamic systems calculated by Harmonic Balance Method (HBM). The HBM offers fast and robust solutions for strongly non-linear systems operating in periodic regimes, however, the phase information when applying the harmonic balance method is lost. In this paper, a practical scheme for calculating the phase difference for a piecewise oscillator mimicking a vibro-impact system is proposed.     

Effect of drying methods on the content of natural pigments and antioxidant capacity in extracts from medicinal plants: a spectroscopic study

Medicinal plants are a significant source of biological active and health protective compounds. Post-harvest treatments can affect, in different ways, the content and biological activity of such compounds. One of the most common post-harvesting methods is drying. In this study, we investigated the effect of drying method on the content of natural pigments (chlorophylls, carotenoids and anthocyanins) and on the antioxidant capacity of two traditionally used herbs, the Melissa officinalis (lemon balm) and the Urtica dioica (stinging nettle) both of them landraces collected from plants grown in Nitra region, West of Slovakia. The freeze-dried samples of both herbs exhibited the highest content of chlorophyll a (7.55 ± 0.13 mg/g dry mass for lemon balm and 9.41 ± 0.17 mg/g dry mass for stinging nettle), chlorophyll b (3.12 ± 0.28 mg/g dry mass for lemon balm and 3.34 ± 0.24 mg/g dry mass for stinging nettle) and carotenoids (2.11 ± 0.24 mg/g dry mass for lemon balm and 2.62 ± 0.06 mg/g dry mass for stinging nettle). The content of chlorophylls and carotenoids correlated with the DPPH antioxidant (radical scavenging) capacity. Higher antioxidant capacity of the lemon balm extracts compared to nettle samples was attributed to the higher content of polyphenol compounds anthocyanins. Despite the higher cost, the freeze drying (lyophilisation) was recommended as the most suitable drying method, mainly for reasons of preserving maximum pigment content and antioxidant capacity.     

Lipoic Acid Combined with Melatonin Mitigates Oxidative Stress and Promotes Root Formation and Growth in Salt-Stressed Canola Seedlings (Brassica napus L.)

Lipoic acid (LA) and melatonin (MT) are pleiotropic molecules participating in plant stress resistance by modulating cellular biochemical changes, ion homeostasis, and antioxidant enzyme activities. However, the combined role of these two molecules in counteracting the detrimental impacts of salinity stress is still unknown. In the present study, we determined the effects of exogenous LA (0.5 µM), MT (1 µM) and their combination (LA + MT) on growth performance and biomass accumulation, photosynthetic pigments, enzymatic and non-enzymatic antioxidant activities, and ions homeostatic in canola (Brassica napus L.) seedlings under salinity stress (0, 100 mM) for 40 days. The results indicate that exogenous application of LA + MT improved the phenotypic growth (by 25 to 45%), root thickness (by 68%), number of later lateral roots (by 52%), root viability (by 44%), and root length (by 50%) under salinity stress. Moreover, total soluble protein, chlorophyll pigments, the concentration of superoxide dismutase (SOD), catalase peroxidase (CAT), and ascorbic peroxidase (ASA) increased with the presence of salt concentration into the growth media and then decreased with the addition of LA + MT to saline solution. Leaf protein contents and the degradation of photosynthetic pigments were lower when LA + MT treatments were added into NaCl media. The proline and phenol contents decreased in the exogenous application of LA + MT treatments more than individual LA or MT treatments under the salinity stress. The incorporation of LA or MT or a combination of LA + MT to saline solution decreased salinity-induced malondialdehyde and electrolyte leakage. In conclusion, the alteration of metabolic pathways, redox modulation, and ions homeostasis in plant tissues by the combined LA and MT application are helpful towards the adaptation of Brassica napus L. seedlings in a saline environment. The results of this study provide, for the first time, conclusive evidence about the protective role of exogenous LA + MT in canola seedlings under salinity stress.     

Development of a new highly efficient 17 X‐STR multiplex for forensic purposes

Currently, two of the most widely used X‐chromosome STR (X‐STR) multiplexes are composed by ten (GHEP‐ISFG decaplex) and 12 markers (Investigator Argus X‐12 Kit). The number of markers included is a drawback for complex relative testing cases, likewise the large size of some amplicons difficult their application to degraded samples. Here, we present a new multiplex of 17 X‐STRs with the aim of increasing both the resolution power and forensic applicability. This newly proposed set includes the X‐STRs of the GHEP‐ISFG decaplex, four X‐STRs from the Investigator Argus X‐12 Kit, three of them also included in the decaplex, and six additional more. In order to ensure the allele designation, an allelic ladder was developed. The validation of the present multiplex was carried out according to the revised guidelines by the SWGDAM (Scientific Working Group on DNA Analysis Methods). A total of 488 unrelated individuals from four different continents were analyzed. The forensic efficiency evaluation showed high values of combined power of discrimination in males (≥0.999999996) and females (≥0.999999999999995) as well as combined paternity exclusion probabilities in trios (≥0.99999998) and duos (≥0.999996). The results presented herein have demonstrated that the new 17 X‐STR set constitutes a high‐resolution alternative to the current X‐STR multiplexes.     

Conley–Morse–Forman Theory for Combinatorial Multivector Fields on Lefschetz Complexes

We introduce combinatorial multivector fields, associate with them multivalued dynamics and study their topological features. Our combinatorial multivector fields generalize combinatorial vector fields of Forman. We define isolated invariant sets, Conley index, attractors, repellers and Morse decompositions. We provide a topological characterization of attractors and repellers and prove Morse inequalities. The generalization aims at algorithmic analysis of dynamical systems through combinatorialization of flows given by differential equations and through sampling dynamics in physical and numerical experiments. We provide a prototype algorithm for such applications.