Multifractal Behaviour of n-Simplex Lattice

We study the asymptotic behaviour of resistance scaling and fluctuation of resistance that give rise to flicker noise in an {\em n}-simplex lattice. We propose a simple method to calculate the resistance scaling and give a closed-form formula to calculate the exponent, $\beta_L$, associated with resistance scaling, for any n. Using current cumulant method we calculate the exact noise exponent for n-simplex lattices.Comment: Latex, 9 pages including one figur

Risk Factors for Anaplastic Thyroid Cancer

Background. Anaplastic thyroid cancer (ATC) is a form of thyroid cancer with very poor prognosis, but is fortunately quite rare. Its aetiology is unknown and not well researched. Aim. The aim of this study was to identify potential risk factors for ATC. Material and Method. Case-control study of 126 ATC patients (77 females and 49 males) and 252 controls individually matched by gender, age, and place of abode. In statistical analysis we used a Cox regression model. Results. Univariate logistic regression showed that the risk factors for ATC are low education level, type B blood group, goitre, other nonthyroid malignancies, diabetes, late menarche, and an early first pregnancy. Multivariate logistic regression analysis showed that independent risk factors for ATC are low education level (OR = 1.42, 95% CI = 1.09-1.86), type B blood group (OR = 2.41, 95% CI = 1.03-5.66), and goitre (OR = 25-33, 95% CI = 5.66-126.65). Conclusion. Independent risk factors for ATC are: low education level, type B blood group, and goitre

Synthesis and Biological Screening of New 4-Hydroxycoumarin Derivatives and Their Palladium(II) Complexes

Two newly synthesized 4-hydroxycoumarin bidentate ligands (L1 and L2) and their palladium(II) complexes (C1 and C2) were screened for their biological activities, in vitro and in vivo. Structures of new compounds were established based on elemental analysis, 1H NMR, 13C NMR, and IR spectroscopic techniques. The obtained compounds were tested for their antioxidative and cytotoxic activities and results pointed to selective antiradical activity of palladium(II) complexes towards •OH and -•OOH radicals and anti-ABTS (2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) cation radical) activity comparable to that of ascorbate. Results indicated the effect of C1 and C2 on the enzymatic activity of the antioxidative defense system. In vitro cytotoxicity assay performed on different carcinoma cell lines (HCT166, A375, and MIA PaCa-2), and one healthy fibroblast cell line (MRC-5) showed a cytotoxic effect of both C1 and C2, expressed as a decrease in carcinoma cells' viability, mostly by induction of apoptosis. In vivo toxicity tests performed on zebrafish embryos indicated different effects of C1 and C2, ranging from adverse developmental effect to no toxicity, depending on tested concentration. According to docking studies, both complexes (C1 and C2) showed better inhibitory activity in comparison to other palladium(II) complexes

Antimicrobial peptide gramicidin S is accumulated in granules of producer cells for storage of bacterial phosphagens

Many antimicrobial peptides are synthesized non-ribosomally in bacteria, but little is known about their subcellular route of biosynthesis, their mode of intracellular accumulation, or their role in the physiology of the producer cells. Here, we present a comprehensive view on the biosynthesis of gramicidin S (GS) in Aneurinibacillus migulanus, having observed a peripheral membrane localization of its synthetases. The peptide gets accumulated in nano-globules, which mature by fusion into larger granules and end up within vacuolar structures. These granules serve as energy storage devices, as they contain GS molecules that are non-covalently attached to alkyl phosphates and protect them from dephosphorylation and premature release of energy. This finding of a fundamentally new type of high-energy phosphate storage mechanism can explain the curious role of GS biosynthesis in the physiology of the bacterial producer cells. The unknown role of the GrsT protein, which is part of the non-ribosomal GS synthetase operon, can thus be assumed to be responsible for the biosynthesis of alkyl phosphates. GS binding to alkyl phosphates may suggest its general affinity to phosphagens such as ATP and GTP, which can represent the important intracellular targets in pathogenic bacteria

Development of new composites made of waste materials for wood pallet element

The recycling of waste products and its further use for new products is of the utmost importance nowadays. The quantities of waste product originating from industries involving plastics, paper, wood, textile and metal foils, such as the related automotive, paper, wood and food industries, represent extremely large numbers, strongly indicating the need for efficient waste management. On the other side of things, companies are always looking for ways to lower material costs. The combination of different waste materials can be used for production of new composite materials. This paper will present a brief overview of existing possibilities in the development of new composites completely made of waste materials, as well as further research directions. A preliminary study of material combinations that can provide a composite aimed at load bearing applications is given, for the purpose of replacing elements such as wood blocks in transport pallets. Several combinations of waste material from different industries were studied in a composite structure: paper, cardboard boxes, tetra-pak containers, expanded polystyrene (styrofoam), polyurethane (PU) foam, artificial leather, textile, wood chips and dust. Preliminary compressive tests were performed. The results indicated unsuitable combinations, but also some that provided a stable compact composite which endured high compressive loads. An important result is that such a composite can be made without adding any adhesives. Waste materials from different industries can be efficiently used for new composites, and further study of this is clearly needed