Dynamic adsorption of trinitrotoluene on granular activated carbon

The effects of trinitrotoluene (TNT) dynamic adsorption on granular activated carbon produced by 'Miloje Zakic', Serbia, are presented. The main task was to determine the conditions for TNT dynamic adsorption in order to remove the dissolved TNT from wastewater. The effects of temperature, concentration and flow rate in the chromatographic system were examined. Flow rates between 1 and 4 dm(3)/h were used. The heights of activated carbon in the columns were 70 and 135 mm while the diameter was 12 mm. The experiments were conducted at different temperatures (10-60 degrees C) and TNT influent concentrations ranging from 32.76 to 171 mg/dm(3) were used. The adsorption capacity of the activated carbon increased with increasing temperature, but it decreased with increasing input concentration and flow rate. The results obtained indicate that the influence of temperature is greater than was expected and the bed height and the amount of GAC used could be significantly lowered by increasing the temperature. The possibility of desorbing TNT from saturated activated carbon was also investigated. The amount of TNT adsorbed per mass unit of adsorbent was calculated using a model that optimally agreed with the experimental data.     

Functional Specialization within the EXO70 Gene Family in Arabidopsis

Localized delivery of plasma-membrane and cell-wall components is a crucial process for plant cell growth. One of the regulators of secretory-vesicle targeting is the exocyst tethering complex. The exocyst mediates first interaction between transport vesicles and the target membrane before their fusion is performed by SNARE proteins. In land plants, genes encoding the EXO70 exocyst subunit underwent an extreme proliferation with 23 paralogs present in the Arabidopsis (Arabidopsis thaliana) genome. These paralogs often acquired specialized functions during evolution. Here, we analyzed functional divergence of selected EXO70 paralogs in Arabidopsis. Performing a systematic cross-complementation analysis of exo70a1 and exo70b1 mutants, we found that EXO70A1 was functionally substituted only by its closest paralog, EXO70A2. In contrast, none of the EXO70 isoforms tested were able to substitute EXO70B1, including its closest relative, EXO70B2, pointing to a unique function of this isoform. The presented results document a high degree of functional specialization within the EXO70 gene family in land plants.     

IMPACT OF HIGH-LEVEL KNOWLEDGE ON ECONOMIC WELFARE THROUGH INTERACTIVE DATA MINING

This paper describes a novel algorithm for finding the most important relations with the use of data mining. As an example application, the impact of high-level knowledge on economic welfare was analyzed. Our approach, based on interactive data mining, not only helps to discover the most relevant models, but also enables an evaluation of their relevance. The approach is specialized for the analysis of macroeconomic data that often contains incomplete and noisy attributes and, initially, complex relations, where several relations are statistically seemingly important, but only a few are indeed the most relevant. Although data mining algorithms are designed to detect the relevant attributes, irrelevant attributes often appear in the models due to chance-choice, reducing their quality and understandability, and consequently even leading to incorrect conclusions. We present our method and show its application at finding the most relevant relations between high-level knowledge and the state of development of a country.     

Chemically Functionalized Carbon Nanotubes as Substrates for Neuronal Growth

We report the use of chemically modified carbon nanotubes as a substrate for cultured neurons. The morphological features of neurons that directly reflect their potential capability in synaptic transmission are characterized. The chemical properties of carbon nanotubes are systematically varied by attaching different functional groups that confer known characteristics to the substrate. By manipulating the charge carried by functionalized carbon nanotubes we are able to control the outgrowth and branching pattern of neuronal processes.     

An approach for reduction of the volume loss in the rigid-plastic FEM using two-step updating procedure

The volume loss, as a direct consequence of the geometry updating procedure used in the conventional penalty rigid-plastic finite element method (RPFEM), is primarily caused by the application of the widely used forward Euler time integration method. In order to decrease this undesired consequence, the combination of the two-step Adams-Bashforth time integration method and the volumetrically elastic and deviatorically RPFEM is proposed as a new approach. The cylinder upsetting process was simulated using in-house finite element code. The results of simulations, obtained for the various levels of friction factors and height reductions, show that the proposed method gives a significantly lower volume loss. Also, the results of the friction factor determination procedure utilising the ring compression test for three lubrication conditions demonstrate the capabilities of the proposed method.     

Chemically functionalized water soluble single-walled carbon nanotubes modulate neurite outgrowth

We report the use of chemically-functionalized water soluble single-walled carbon nanotube (SWNT) graft copolymers for modulation of outgrowth of neuronal processes. The graft copolymers were prepared by the functionalization of SWNTs with poly-m-aminobenzene sulphonic acid and polyethylene glycol. When added to the culturing medium, these functionalized water soluble SWNTs were able to increase the length of various neuronal processes.     

The influence of the dispersed phase on the morphology,mechanical and thermal properties of PLA/PE‐LD and PLA/PE‐HD polymer blends and their nanocomposites with TiO2 and CaCO3

This research investigated the impact of different processing temperature (extrusion at 160°C and 180°C) and the influence of the TiO₂ and CaCO₃ fillers on morphology, mechanical, and thermal properties of polylactide (PLA) blended with low‐density polyethylene (PE‐LD) and high‐density polyethylene (PE‐HD) in 90/10 weight ratio. The impact of the particle size of the filler was also examined with the three types of TiO₂ filler. It has been shown that the different processing temperature has no significant impact on the morphology, mechanical, and thermal properties of PLA/PE‐LD 90/10 and PLA/PE‐HD 90/10 polymer blends. It has also been shown that better phase interaction is not the crucial factor for the improvement of the mechanical properties but the domain size distribution of the dispersed phase within the matrix and the dispersion of the filler are. Samples with a narrow size distribution of the dispersed phase domain (5 to 10 μm) with the higher portion of larger domains that are uniformly distributed within the polymer matrix showed best mechanical properties. POLYM. ENG. SCI., 59:1395–1408 2019. © 2019 Society of Plastics Engineers     

Halogenated boroxine dipotassium trioxohydroxytetrafluorotriborate K2[B3O3F4OH] inhibits emerging multidrug-resistant and β-lactamase-producing opportunistic pathogens

Abstract

Halogenated boroxine dipotassium trioxohydroxytetrafluorotriborate, K₂[B₃O₃F₄OH] (boroxine) was previously shown to be very effective in inhibition of several carcinoma cell lines, including the skin cancer. Here, we investigated its antimicrobial potential by targeting the multidrug-resistant opportunistic pathogens associated with skin and wound infections. The antimicrobial testing against eleven bacterial and four fungal species revealed good activity of boroxine against pathogenic filamentous fungi Penicillium funiculosum and Aspergillus niger (MIC₅₀ 64 and 128?µg/ml), and a moderate bioactivity against the yeast Candida albicans (MIC₅₀ 512?µg/ml). Among the tested multidrug-resistant bacteria, the best antibacterial effect, stable over a 24-h period, was observed against the methicillin-resistant Staphylococcus aureus strain (MRSA) at MIC of 1024?µg/ml. The atomic force microscopy (AFM) used to investigate the morphology of S. aureus cells revealed indentations on its cell envelope after the boroxine exposure. These results show that in addition to the antitumor effect, boroxine exerts wide spectrum antimicrobial activity, thus may help preventing the development of skin and wound-related opportunistic infections.