Compositional studies: antioxidant and antidiabetic activities of Capparis decidua (Forsk.) Edgew

Capparis decidua is one of the traditional remedies used for various medicinal treatments in Pakistan. This study presents the determination of proximate composition, amino acids, fatty acids, tocopherols, sterols, glucosinolate and phenolic content in extracts obtained from different aerial parts of C. decidua, as well as their antidiabetic and antioxidant activity. All examined extracts were prominently rich in phenolics and glucosinates, and they showed potent antidiabetic and antihemolytic activity. The present study could be helpful in developing medicinal preparations for the treatment of diabetes and related symptoms.     

Teucrium plant species as natural sources of novel anticancer compounds: antiproliferative, proapoptotic and antioxidant properties

This study deals with total phenolic content, antiproliferative and proapoptotic activity of methanolic extracts from different Teucrium species and the effect on the prooxidant/antioxidant status in HCT-116 cells. The total phenolic content of the extracts was measured spectrophotometricaly and the obtained results ranged from 56.62 mg/g to 172.50 mg GA/g. The antiproliferative activity of methanolic extracts from different Teucrium species was determined using MTT cell viability assay, where IC(50) value was used as a parameter for cytotoxicity. The type of cell death was explored by fluorescence microscopy using the acridin orange/ethidium bromide method. MTT assay showed that all extracts significantly reduced cell viability in a dose-dependent manner, with very low IC(50) values. The highest content of phenolic compounds and the best cytotoxic activity on HCT-116 cells after 24 h of exposure was in T. chamaedrys extract, with IC(50) values of 5.48 × 10(-9) μg/mL. After 72 h, methanolic extract of T. arduini appeared to have the best cytotoxic activity on HCT-116, with IC(50) values of 0.37 μg/mL. Treatments caused typical apoptotic morphological changes in HCT-116 cells and showed a high percentage of apoptotic cells. The results of the presented research indicate that some Teucrium extracts are a very rich source of phenols, which may directly contribute to high antiproliferative and proapoptotic activity.     

Synthesis and characterization of novel urethane‐siloxane copolymers with a high content of PCL‐PDMS‐PCL segments

Novel polyurethane copolymers derived from 4,4′‐methylenediphenyl diisocyanate (MDI), 1,4‐butanediol (BD) and α,ω‐dihydroxy‐[poly(caprolactone)‐poly (dimethylsiloxane)‐poly(caprolactone)] (α,ω‐dihydroxy‐(PCL‐PDMS‐PCL); = 6100 g mol^?1) were synthesized by a two‐step polyaddition reaction in solution. In the synthesis of the polyurethanes, the PCL blocks served as a compatibilizer between the nonpolar PDMS blocks and the polar comonomers, MDI and BD. The synthesis of thermoplastic polyurethanes (TPU) with high soft segment contents was optimized in terms of the concentrations of the reactants, the molar ratio of the NCO/OH groups, and the time and temperature of the polyaddition reaction. The structure, composition, and hard MDI/BD segment length of the synthesized polyurethane copolymers were determined by ¹H, ¹³C‐NMR, and two‐dimensional correlation (COSY, HSQC, and HMBC) spectroscopy, while the hydrogen bonding interactions in the copolymers were analyzed by FT‐IR spectroscopy. The influence of the reaction conditions on the structure, molecular weight, thermal, and some physical properties was studied at constant composition of the reaction mixture. A change in the molar ratio of the NCO/OH groups and the reaction conditions modified not only the molecular weight of the synthesized polyurethanes, but also the microstructure and therefore the thermal and physical properties of the copolymers. It was demonstrated that only PCL segments with high soft segment contents crystallize, thereby showing spherulitic morphology. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Optimal FIR filter for suppression of power line frequency component

In this paper a design technique for multiband FIR filter for DC and power line frequency component suppression is described. The digital filter has a linear phase characteristic and equiripple amplitude characteristic in the passband. The amplitude characteristic of this filter satisfies the alternation theorem and consequently has the lowest complexity in obtaining a prescribed maximum deviation in the passband and the fastest possible rate of attenuation near the cutoff frequency. In this sense this filter is optimal. Closed-form expressions for direct calculation of filter coefficients, cutoff frequency and maximal passband attenuation are derived.     

Sensorless induction motor drive with a single DC-link currentsensor and instantaneous active and reactive power feedback

This paper proposes a novel torque and speed control structure for low-cost induction motor variable-speed drives with a single DC-link current sensor. The controller is based on reconstruction of the active and instantaneous reactive power from the DC-link current without the use of a shaft sensor. An effective way of achieving tracking of set values of motor torque and flux is to base the estimation on the instantaneous active (P) and reactive power (Q). The paper proposes a way for extracting instantaneous P and Q information from the DC-link current and the pulsewidth modulation pattern. Torque and flux controllers suitable for general purpose and traction applications are proposed. The paper presents analytical considerations, straightforward design guidelines, and experimental results obtained from a traction system with a battery-fed three-phase inverter and a 7.5 kW traction motor     

Application of GC–MSD and LC–MS/MS for the determination of priority pesticides in baby foods in Serbian market

Babies and small children are especially sensitive population to the exposure to environmental contaminants. Their small mass and developing systems, including brain development may show adverse health effects from even low levels of contamination on a chronic or single dose case. In this paper one extraction method and two chromatographic techniques for the determination of pesticide residues in baby food were evaluated. A liquid chromatography–tandem mass spectrometry technique combined with electrospray ionization (ESI), (LC–MS/MS) and gas chromatography–mass spectrometry detection (GC–MSD) technique were applied in the detection of 50 pesticides in baby food. So-called QuEChERS (quick, easy, cheap, effective, rugged and safe) method was used as a sample preparation procedure. The recoveries were investigated at three levels (5, 10 and 50 μg/kg) and the results obtained showed compliance with the contemporary EU requirements with a few exceptions. LOQs for most of the tested pesticides were below the EU MRLs (10 μg/kg), except deltamethrin, cypermethrin, fenvalerate, phosalone and beta-cyfluthrin (LOQs were 10 μg/kg). Both techniques were applied in the analysis of 50 samples of baby food manufactured in Serbia.     

A multi-agent architecture for dynamic scheduling of steel hot rolling

Steel production is a complex process and finding coherent and effective schedules for the wide variety of production steps, in a dynamic environment, is a challenging task. In this paper, we propose a multi-agent architecture for integrated dynamic scheduling of the hot strip mill (HSM) and the continuous caster. The scheduling systems of these processes have very different objectives and constraints, and operate in an environment where there is a substantial quantity of real-time information concerning production failures and customer requests. Each process is assigned to an agent which independently, seeks an optimal dynamic schedule at a local level taking into account local objectives, real-time information and information received from other agents. Each agent can react to real-time events in order to fix any problems that occur. We focus here, particularly, on the HSM agent which uses a tabu search heuristic to create good predictive–reactive schedules quickly. The other agents simulate the production of the coil orders and the real-time events, which occur during the scheduling process. When real-time events occur on the HSM, the HSM agent might decide whether to repair the current schedule or reschedule from scratch. To address this problem, a range of schedule repair and complete rescheduling strategies are investigated and their performance is assessed with respect to measures of utility, stability and robustness, using an experimental simulation framework.     

Influence of nitrogen content on the pit formation and pit propagation in the welded joints of X5CrNi18-10 stainless steel

The influence of welding current and nitrogen content in argon shielding gas on the resistance of the welded joint (weld metal and heat-affected zone [HAZ]) of the stainless steel X5CrNi18-10 to the formation and growth of pits was investigated. Also, the susceptibility of the welded joint to intergranular corrosion was examined. Pitting corrosion resistance indicators were determined based on anodic potentiodynamic polarization measurements in NaCl + Na₂SO₄ solution, while susceptibility to intergranular corrosion was determined by the potentiokinetic method with a double loop (DL EPR). SEM/EDS was used to analyze the microstructure. It has been shown that higher nitrogen content in shielding gas leads to an increase in the resistance of welded joints (weld metal and HAZ) to the pit formation. However, an improvement in the resistance to the pit formation leads to a decline in the resistance of the welded joint to pit growth. An explanation of this phenomenon is proposed. Also, it was shown that the increase of the welding current increases the susceptibility of the welded joint to intergranular corrosion, while the higher nitrogen content has no effect.     

离散随机系统的包含原理

提出线性时变离散随机系统的包含原理.根据系统包含的定义,给出系统状态观测与反馈控制闭环系统的约束条件和聚集条件,使具有重叠结构和模型降阶系统的反馈设计或LQG设计有充分的选择.     

Quinoline-Conjugated Ruthenacarboranes: Toward Hybrid Drugs with a Dual Mode of Action

The role of autophagy in cancer is often complex, ranging from tumor-promoting to -suppressing effects. In this study, two novel hybrid molecules were designed, containing a ruthenacarborane fragment conjugated with a known modulator of autophagy, namely a quinoline derivative. The complex closo-[3-(η⁶-p-cymene)-1-(quinolin-8-yl-acetate)-3,1,2-RuC₂B₉H₁₀] ( 4 ) showed a dual mode of action against the LN229 (human glioblastoma) cell line, where it inhibited tumor-promoting autophagy, and strongly inhibited cell proliferation, de facto blocking cellular division. These results, together with the tendency to spontaneously form nanoparticles in aqueous solution, make complex 4 a very promising drug candidate for further studies in vivo, for the treatment of autophagy-prone glioblastomas.