Effects of 3-Hydrogenkwadaphnin on intracellular purine nucleotide contents and their link to K562 cell death

Our previous studies have classified 3-Hydrogenkwadaphnin (3-HK), isolated from Dendrostellera lessertii (Thymelaeaceae), as a strong anti-proliferative agent that induces apoptosis among the treated leukemia cells mainly through IMP dehydrogenase inhibition. To disclose this point, we measured the intracellular ATP and GTP levels among K562 cells exposed to a single dose of 3-HK (7, 12 and 25 nM). The HPLC analyses of the 3-HK-treated cell lysates indicated a dose-dependent reduction in both GTP and ATP levels. The reduction of purine nucleotide levels was also associated with decreased activity of adenylosuccinate synthetase (AdSS) and enhanced level of cell death through apoptosis. However, the inhibitory effect of 3-HK was reversed by exogenous addition of guanosine with respect to GTP and partially with respect to ATP level. These data suggest that 3-HK targets a delicate regulatory system which governs the life/death fate of the cells partially through modulation of the GTP/ATP pool sizes.     

Factors Controlling Gully Advancement and Models Evaluation (Hableh Rood Basin,Iran)

Gully erosion is one of the most complicated and destructive forms of water erosion. In order to prevent this erosion, the important factors controlling gully heads must be understood. This paper examines gully head advancement in the Hableh Rood Basin, Iran by (1) observing gully head advance between 1957 and 2005 using field studies, aerial photography and GIS analysis and: (2) applying and evaluating widely used experimental models including the, Thompson (Trans ASAE 7(1):54–55, 1964), SCS (I) and SCS (II) models, for estimating migrating headcuts over the study period. The results showed that the highest mean gully advancement (0.26 m year^− 1) took place during the 1956–1967 period, with most gullies having lower and steady headcut retreat rates between 1967–2000 (0.21 m year^− 1) and 2000–2005 (0.15 m year^− 1). This suggests that the majority of gullies in the study area were still in the early stages of formation in the first study period and their formation may be linked to land use or climatic changes pre 1956. Analysis of the correlation between environmental characteristics of the study area and gully advancement indicated that the upslope area of head cuts and soluble mineral content of the soil were the two most important factors influencing the spatial and temporal variation of gully longitudinal development. Results of multiple regression revealed that the simple relation including upslope area and soluble minerals can explain 93% of total variance and relatively reflects the effects of runoff and waterfall process for headcut retreat. Application of statistical error analysis to evaluate the four gully advancement models showed that in comparison to other models, the second model of SCS has more reliable results for predicting longitudinal gully advancement in this study area and other similar regions. However, this study indicates that future modelling in the region should consider the role of soil soluble mineral content in predicting gully advancement.     

Synthesis and properties of new highly soluble poly(amide-ester-imide)s containing poly(ethylene glycol) as a soft segment

In this study, a new class of highly soluble poly(amide-ester-imide)s (PAEI)s contains poly(ethyleneglycol) (PEG) as hydrophilic and soft segment were prepared. Poly(ethylene glycol)-bis-(N-trimellitylimido-4-phenyl carboxylic acid) (3) as a novel diacid monomer was synthesized via two step. The reaction of poly(ethylene glycol) (PEG 6000) with trimellitic anhydride chloride yield poly(ethylene glycol)-bis-trimellitic anhydride (1). The reaction of dianhydride 1 with p-aminobenzoic acid (2) produces novel diacid monomer 3. The direct polycondensation technique of the diacid 1 with several aromatic diamines was carried out in pyridine/N-methyl-2-pyrrolidone/triphenylphosphite/CaCl₂ as condensing agent. The resulting novel PAEIs with inherent viscosities ranging between 0.21 and 0.42 dl g⁻¹, were obtained in good yield. This group of polymers exhibit excellent solubility in a variety of organic solvents and water. All of these polymers were characterized with FT-IR spectroscopy. Thermal properties, ¹H-NMR and XRD study of these PAEIs were also reported. The results demonstrate that this polymers show crystalline structure as well as high thermal stability. In addition the effect of PEG length on solubility and thermal properties of the polymers were also studied.     

Tuning Parameters of the QoS-Aware Routing Protocol for Smart Grids Using Genetic Algorithm

Smart Grid (SG) incorporates various data communication networks to cover the complicated power systems in an intelligent and efficient way. This network utilizes the mutual flows of the data and electricity to facilitate the relations among the network components. One of the most attractive areas in the SG is the routing optimization, by which the data transmission is accompanied by Quality of Service (QoS) assurance. In this article, we tune the suggested parameters of the genetic-algorithm-inspired QoS-aware routing protocol, namely Genetic Algorithm Stable Optimization Multiconstrained Routing (GASOMCR) protocol. The QoS requirements are extracted to monitor the degree of user satisfaction of the services as well as ensure the QoS existence in the routing approach. Different sets of parameters, i.e., packet loss, path loss, effective throughput, network criticality, network availability, packet transmission delay, and connection outage probability are used to assess the QoS of the SG. These parameters are analyzed and the behavior of the network cost function is determined for each of these parameters. Appropriate parameterization of the proposed GA is very effective in the performance convergence of the network. The results obtained by GASOMCR protocol show that the performance improvement, which is obtained from minimizing the network cost function as well as having the trade-off among the various proposed parameters, is obviously achieved.     

Revealing quantum correlation by negativity of the Wigner function

We analyze two two-mode continuous variable separable states with the same marginal states. We adopt the definition of classicality in the form of well-defined positive Wigner function describing the state and find that although the states possess positive local Wigner functions, they exhibit negative Wigner functions for the global states. Using the negativity of Wigner function as an indicator of nonclassicality, we show that despite these states possess different negativities of the Wigner function, they do not reveal this difference as phase space nonclassicalities such as negativity of the Mandel Q parameter or quadrature squeezing. We then concentrate on quantum correlation of these states and show that quantum discord and local quantum uncertainty, as two well-defined measures of quantum correlation, manifest the difference between negativity of the Wigner functions. The non-Gaussianity of these states is also examined and show that the difference in behavior of their non-Gaussianity is the same as the difference between negativity of their Wigner functions. We also investigate the influence of correlation rank criterion and find that when the states can be produced locally from classical states, the Wigner functions cannot reveal their quantum correlations.     

Cryptanalysis of a multiparty quantum key agreement protocol based on commutative encryption

Recently, Sun et al. (Quantum Inf Process 15(5):2101–2111, 2016) proposed an efficient multiparty quantum key agreement protocol based on commutative encryption. The aim of this protocol is to negotiate a secret shared key among multiple parties with high qubit efficiency as well as security against inside and outside attackers. The shared key is the exclusive-OR of all participants’ secret keys. This is achieved by applying the rotation operation on encrypted photons. For retrieving the final secret key, only measurement on single states is needed. Sun et al. claimed that assuming no mutual trust between participants, the scheme is secure against participant’s attack. In this paper, we show that this is not true. In particular, we demonstrate how a malicious participant in Sun et al.’s protocol can introduce “a” final fake key to target parties of his choice. We further propose an improvement to guard against this attack.     

Green synthesis of silver nanoparticles and their applications as colorimetric probe for determination of Fe3+ and Hg2+ ions

Silver nanoparticles (AgNPs) were prepared by a green method using Cordia myxa leaf extract. They were characterised by UV–vis spectroscopy, Fourier transform infrared spectroscopy and their X‐ray diffraction pattern. Their sizes were determined by scanning electron micrographs, transmission electron micrographs imaging and dynamic light scattering analysis. The shapes of nanoparticles were spherical or truncated triangular and their average size was determined to be 51.6 nm. Their solution was stable at least for one month. The prepared AgNPs were used as a selective chemical sensor for determination of iron(III) (only when Cl⁻ ions were present in the medium) and mercury(II) ions with detection limits of 0.084 and 0.037 nM, respectively. It was shown that the mechanism of these detections is through oxidation of Ag atoms by Fe³⁺ and Hg²⁺ ions.Inspec keywords: visible spectra, nanoparticles, transmission electron microscopy, nanofabrication, ultraviolet spectra, chemical sensors, scanning electron microscopy, silver, X‐ray diffraction, Fourier transform infrared spectra, oxidationOther keywords: Ag, Cordia myxa leaf extract, iron(III) ions, mercury(II) ions, oxidation, scanning electron micrographs, Fourier transform infrared spectroscopy, silver nanoparticles, chemical sensor, dynamic light scattering analysis, transmission electron micrographs, X‐ray diffraction pattern, UV–vis spectroscopy, colorimetric probe, green synthesis     

Antioxidant and free radical scavenging potential of Achillea santolina extracts

The antioxidative activities of hydroalcoholic extract of Achillea santolina were investigated employing various established in vitro systems including total antioxidant activity in linoleic acid emulsion system, 1,1-diphenyl-2-picrylhydrazyl (DPPH), superoxide and hydroxyl radicals scavenging, reducing power, and inhibitory effect on protein oxidation as well as the inhibition of Fe²⁺/ascorbate induced lipid peroxidation in rat liver homogenate. Total phenolic and flavonoid content of A. santolina extract (ASE) was also determined by a colorimetric method. The results revealed that ASE has notable inhibitory activity on peroxides formation in linoleic acid emulsion system along with concentration-dependent quenching of DPPH and superoxide radicals. Furthermore, the extract showed both nonsite-specific (Fe²⁺ + H₂O₂ + EDTA) and site-specific (Fe²⁺ + H₂O₂) hydroxyl radical scavenging suggesting potent hydroxyl radical scavenging and chelating ability for iron ions in deoxyribose degradation model. A linear correlation between ASE and the reducing power was also observed (r² = 0.9981). ASE prevents thiobarbituric acid reactive substances formation in Fe²⁺/ascorbate induced lipid peroxidation in rat liver tissue in a dose-dependent manner. Moreover, free radical induced protein oxidation was suppressed significantly by the addition of ASE over a range of concentration. These results clearly demonstrated that A. santolina extract possess a marked antioxidant activity.