Anti-Candida activity of ethanolic extracts of Iranian endemic medicinal herbs against Candida albicans

It has long been known that herbs and their extracts have antimicrobial activities. Heracleum lasiopetalum Boiss., Satureja bachtiarica Bunge., Thymus daenensis Celak., Echiophora platyloba L., Dracocephalum multicaule Benth., Kelussia odoratissima Mozaff. and Achillea kellalensis Boiss. are Iranian endemic plant species that have been traditionally used as medicinal herbs and spices in different regions of Iran especially Central Zagross. Seven ethanolic extracts of endemic medicinal herbs and one extract of native medicinal herb (Stachys lavandulifolia Vahl.) collected from Chaharmahal va Bakhtiari province of Iran were assayed for the in vitro antifungal activity against Candida albicans (ATCC1023), using agar dilution methods. Most of the extracts showed relatively high anti-Candida activity against the tested fungi with the diameter of inhibition zone ranging between 8 and 17 mm. The extracts of S. bachtiarica and T. daenensis exhibited high inhibitory effect against C. albicans. The extracts of S. bachtiarica and T. daenensis were characterized using HPLC, the major components of S. bachtiarica and T. daenensis were carvacrol and thymol, respectively. The minimum inhibitory concentration (MIC) values for active extract range between 25 and 50 µg/ml. In conclusion, it can be said that the extract of some of the Iranian endemic medicinal plants (S. bachtiarica and T. daenensis) could be used as natural anti-Candida

Martini 3 : a general purpose force field for coarse-grained molecular dynamics

The coarse-grained Martini force field is widely used in biomolecular simulations. Here we present the refined model, Martini 3 (http://cgmartini.nl), with an improved interaction balance, new bead types and expanded ability to include specific interactions representing, for example, hydrogen bonding and electronic polarizability. The updated model allows more accurate predictions of molecular packing and interactions in general, which is exemplified with a vast and diverse set of applications, ranging from oil/water partitioning and miscibility data to complex molecular systems, involving protein-protein and protein-lipid interactions and material science applications as ionic liquids and aedamers.Peer reviewe

Mechanisms by which salt concentration moderates the dynamics of human serum transferrin

The dynamical and thermodynamic behavior of human transferrin (hTf) protein in saline aqueous solution of various concentrations is studied. hTf is an essential transport protein circulating iron in the blood and delivering it to tissues. It displays highly pH dependent cooperativity between the two lobes, each carrying an iron, and forms a tight complex with the receptor during endocytosis, eventually recycled to the serum after iron release. Molecular dynamics simulations are used to investigate the effects of the amount of salt on protein conformation and dynamics to analyze the structure-function relationship in free hTf at serum pH. To monitor the ionic strength dependence, four different ionic concentrations, 0, 50, 130, and 210 mM NaCl for two protonation states of the iron coordination site is considered. Two mechanisms by which salt affects hTf are disclosed. In the totally closed state where iron coordinating tyrosines are deprotonated, the addition of even 50 mM of salt alters the electrostatic potential distribution around the protein; opening energetic pathways for tyrosine protonation from nearby charged residues as a required first step for iron release. Once domain opening is observed, conformational plasticity renders the iron binding site more accessible by the solvent. At this second stage of iron release, R124 in the N-lobe is identified as kinetically significant anion binding site that accommodates chloride ions and: allosterically communicates with the iron binding residues. Opening motions are maximized at 150 mM IS in the N-lobe, and at 210 mM in the C-lobe. The extra mobility in the latter is thought to preclude binding of hTf to its receptor. Thus, the physiological IS is Optimal for exposing iron for release from hTf. However, the calculated binding affinities of iron show that even in the most open conforinations, iron dissociation needs to be accompanied by chelators

INVESTIGATING SELECTIVE REMOVAL OF Cr(VI) AND Zinc IONS FROM AQUEOUS MEDIA BY MECHANICAL-CHEMICAL ACTIVATED RED MUD

In this study, the adsorption of hexavalent chromium and zinc ions from the solution is investigated by raw red mud and mechanical-chemical activated red mud along with the possibility of selective reclamation of these ions from the solution. The mechanical-chemical activation of red mud was done by employing high-energy milling and subsequent acid treatment with HNO3. Raw red mud (RRM) and mechanical-chemical activated red mud (MCARM) adsorbents were characterized with Fourier transform infrared spectroscopy (FTIR), X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscope (SEM), and Brunauer–Emmett–Teller (BET) methods. In order to determine the suitable adsorption conditions, effects of pH of the solution, amount of adsorption, temperature, and time of adsorption were investigated. It was found that the optimum pH for the adsorption of hexavalent chromium and zinc ions by MCARM adsorbent was 2 and 6, respectively. According to these pH values, MCARM had the ability to separately adsorb more than 95 and 79% of hexavalent chromium and zinc ions from the solution, respectively. Experimental results were in good agreement with Langmuir and Freundlich isotherms. By considering the kinetic models of adsorption, the kinetics of the adsorption of both ions followed the pseudo-second-order reaction model. It was also determined that almost 25.8 and 61.8% of the hexavalent chromium and zinc ions adsorbed in MCARM could be recovere

Mathematical Analysis of Optimal Tracking Interval Management for Power Efficient Target Tracking Wireless Sensor Networks

In this paper, we study the problem of power efficient tracking interval management for distributed target tracking wireless sensor networks (WSNs). We first analyze the performance of a distributed target tracking network with one moving object, using a quantitative mathematical analysis. We show that previously proposed algorithms are efficient only for constant average velocity objects however, they do not ensure an optimal performance for moving objects with acceleration. Towards an optimal performance, first, we derive a mathematical equation for the estimation of the minimal achievable power consumption by an optimal adaptive tracking interval management algorithm. This can be used as a benchmark for energy efficiency of these adaptive algorithms. Second, we describe our recently proposed energy efficient blind adaptive time interval management algorithm called Adaptive Hill Climbing (AHC) in more detail and explain how it tries to get closer to the derived optimal performance. Finally, we provide a comprehensive performance evaluation for the recent similar adaptive time interval management algorithms using computer simulations. The simulation results show that using the AHC algorithm, the network has a very good performance with the added advantage of getting 9 % closer to the calculated minimal achievable power consumption compared with that of the best previously proposed energy efficient adaptive time interval management algorithm