Characterization of monomeric and gemini cationic amphiphilic molecules by fluorescence intensity and anisotropy. Part 2

Four fluorophores of different nature, structure and properties were employed as probes for the characterization of a series of alkanediyl-α,ω-bis(alkyldimethyl ammonium bromide) surfactants. Pyrene and 3-(2-Benzothiazolyl)-7-(diethylamino)coumarin (coumarin 6) fluorescence intensity as well as coumarin 6 and fluorescein sodium salt fluorescence anisotropy were used to determine cmc whilst coumarin 6, fluorescein sodium salt and perylene fluorescence anisotropy was exploited to provide information on micellar structure; cmc values were confirmed using conductivity measurements. Conductivity data were analysed by means of a method which reveals the formation of ion pairs or premicellar aggregates; this approach was useful to justify and confirm results obtained using fluorescence.     

On the Road to Fight Cancer: The Potential of G-Quadruplex Ligands as Novel Therapeutic Agents

Nucleic acid sequences able to adopt a G-quadruplex conformation are overrepresented within the human genome. This evidence strongly suggests that these genomic regions have been evolutionary selected to play a pivotal role in several aspects of cell biology. In the present review article, we provide an overview on the biological impact of targeting G-quadruplexes in cancer. A variety of small molecules showing good G-quadruplex stabilizing properties has been reported to exert an antitumor activity in several preclinical models of human cancers. Moreover, promiscuous binders and multiple targeting G-quadruplex ligands, cancer cell defense responses and synthetic lethal interactions of G-quadruplex targeting have been also highlighted. Overall, evidence gathered thus far indicates that targeting G-quadruplex may represent an innovative and fascinating therapeutic approach for cancer. The continued methodological improvements, the development of specific tools and a careful consideration of the experimental settings in living systems will be useful to deepen our knowledge of G-quadruplex biology in cancer, to better define their role as therapeutic targets and to help design and develop novel and reliable G-quadruplex-based anticancer strategies.     

Suffix tree characterization of maximal motifs in biological sequences

Finding motifs in biological sequences is one of the most intriguing problems for string algorithm designers due to, on the one hand, the numerous applications of this problem in molecular biology and, on the other hand, the challenging aspects of the computational problem. Indeed, when dealing with biological sequences it is necessary to work with approximations (that is, to identify fragments that are not necessarily identical, but just similar, according to a given similarity notion), and this complicates the problem. Existing algorithms run in time linear with respect to the input size. Nevertheless, the output size can be very large due to the approximation (namely exponential in the approximation degree). This often makes the output unreadable, as well as slowing down the inference itself. A high degree of redundancy has been detected in the set of motifs that satisfy traditional requirements, even for exact motifs. Moreover, it has been observed many times that only a subset of these motifs, namely the maximal motifs, could be enough to provide the information of all of them. In this paper, we aim at removing such redundancy. We extend some notions of maximality already defined for exact motifs to the case of approximate motifs with Hamming distance, and we give a characterization of maximal motifs on the suffix tree. Given that this data structure is used by a whole class of motif extraction tools, we show how these tools can be modified to include the maximality requirement without changing the asymptotical complexity.     

First results on biostimulation of denitrifying activated sludge using low frequency ultrasound

Reduction of nitrate to nitrogen is critical for wastewater treatment process. The present work proposed a promising approach to improve the activity of denitrifying activated sludge by using low frequency ultrasonic treatment. Batch activity assays showed that when ultrasound was applied, denitrification performance was 2.64 higher than the control. Kinetic analysis of nitrate removal rate versus ultrasonic power and duty cycle was performed to investigate the effect of operational parameters on activated sludge activities. The best stimulating effect was observed at 40 W ultrasonic power and 40% duty cycle. The above results demonstrated that ultrasonic stimulation can be used as a technique for enhancing bacterial activities for water treatment. Studies of other parameters that also affect the denitrification under ultrasound are under way.     

Physicochemical Properties,Minerals, Trace Elements,and Heavy Metals in Honey of Different Origins: A Comprehensive Review

Honey is a popular natural food product with a very complex composition mainly consisting of both organic and inorganic constituents. The composition of honey is strongly influenced by both natural and anthropogenic factors, which vary based on its botanical and geographical origins. Although minerals and heavy metals are minor constituents of honey, they play vital role in determining its quality. There are several different analytical methods used to determine the chemical elements in honey. These methods are typically based on spectroscopy or spectrometry techniques (including atomic absorption spectrometry, atomic emission spectrometry, inductively coupled plasma mass spectrometry, and inductively coupled plasma optical emission spectrometry). This review compiles available scientific information on minerals and heavy metals in honey reported from all over the world. To date, 54 chemical elements in various types of honey have been identified and can be divided into 3 groups: major or macroelements (Na, K, Ca, Mg, P, S, Cl), minor or trace elements (Al, Cu, Pb, Zn, Mn, Cd, Tl, Co, Ni, Rb, Ba, Be, Bi, U, V, Fe, Pt, Pd, Te, Hf, Mo, Sn, Sb, La, I, Sm, Tb, Dy, Sd, Th, Pr, Nd, Tm, Yb, Lu, Gd, Ho, Er, Ce, Cr, As, B, Br, Cd, Hg, Se, Sr), and heavy metals (trace elements that have a specific gravity at least 5 times higher than that of water and inorganic sources). Chemical elements in honey samples throughout the world vary in terms of concentrations and are also influenced by environmental pollution.     

Indigenous food ingredients for complementary food formulations to combat infant malnutrition in Benin: a review

This paper reviews indigenous Beninese food resources as potential ingredients for complementary infant foods with the aim to develop affordable formulations for low‐income households in each agro‐ecological zone of the country. Potential ingredients were selected on their documented nutritional value. The selected foods encompass 347 food resources, namely 297 plant products from home gardens or collected from natural vegetation and 50 animals, either domesticated or from the wild. The compiled data reveal that the distribution of the available food resources was unbalanced between agro‐ecological zones. Only a few animal ingredients are obtainable in northern Benin. Most resources are seasonal, but their availability may be extended. A high variation was observed in energy and nutrient contents. Antinutritional factors were identified in some resources, but processing techniques were reported to reduce their presence in meals. In general, ingredients from local tree foods (Adansonia digitata, Parkia biglobosa) were adequate as sources of nutrients for complementary infant foods. Based on this review, local foods for the development of complementary food formulas for Beninese infants and children may be selected for each agro‐ecological zone. The approach used is exemplary for other sub‐Saharan African countries in need of complementary infant foods. © 2017 Society of Chemical Industry     

Design,processing, and characterization of an optical core-bioactive clad phosphate fiber for biomedical applications

The aim of this study was to fabricate a bioactive optical fiber able to monitor “in situ” its reaction with the body through changes in its optical properties. Core and cladding preforms were prepared with the composition (97.25*(0.50P₂O₅-0.40SrO-0.10Na₂O)-2.5ZnO-0.25Er₂O₃) and (98.25*(0.50P₂O₅-0.40SrO-0.10Na₂O)-1.75ZnO) (in mol%), respectively, and successfully drawn into a multimode core/clad optical fiber. Optical and near-Infrared images assessed the proper light guiding properties of the fiber. The fibers favor the precipitation of a Ca-P reactive layer at its surface concomitant with a reduction in the fiber diameter, when immersed in SBF, often assigned as a sign of bioactivity. It is clearly shown here that the bio-response of the fiber upon immersion in SBF can be tracked from the decrease in the intensity of the Er³⁺ ions emission at 1.5 µm. This confirms that the newly developed optical fiber, which combines good optical properties with a suitable bioactive behavior, is a promising platform for the development of novel biomedical devices for biophotonic and photomedical applications. Finally, the successful splicing of the newly developed fiber with commercial optical fibers was an evidence of the possibility to integrate the newly developed phosphate fiber within existing components used in the field of biomedicine.