Hazardous impact of toxic metals on tobacco leaves grown in contaminated soil by ultrasonic assisted pseudo-digestion: multivariate study

Tobacco leaves (Nicotiana tabacum L.), agricultural soil and pollute irrigated lake water samples were collected during 2005–2006 and analyzed for Cd and Ni by electrothermal atomic absorption spectrometry (ETAAS). A simple and efficient procedure was investigated for the complete decomposition of tobacco leaves using ultrasonic assisted acid pseudo-digestion method (UPDM). A Plackett–Burman experimental design was used as a multivariate strategy for the evaluation of seven factors/variables at once, while central composite were used to found optimum values of significant variables. The accuracy of the proposed methods was assessed by analyzing certified reference (CRM); Virginia tobacco leaves (CTA-VTL-2). The results being compared with those obtained by conventional wet acid digestion method. The result obtained by optimized method showed good agreement with the certified values and sufficiently high recovery 97.8 and 98.7% for Cd and Ni, respectively. Under optimal conditions, the detection limits (3σ) were evaluated to be 0.019 μg g⁻¹ for Cd and 0.37 μg g⁻¹ for Ni. The proposed method was successfully applied to the determination of Cd and Ni in raw, processed tobacco and different branded cigarettes samples.     

A multivariate study: variation in uptake of trace and toxic elements by various varieties of Sorghum bicolor L

The aim of present study was to evaluate the variation in uptake of elements (As, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb and Zn) by different varieties of Sorghum bicolor L., plants grown in soil amended with untreated industrial waste water sewage sludge (SUIS), on same experimental plots. The power of chemometrics was also used in exploring the potential natural and/or anthropogenic sources responsible for elemental contents in different varieties of sorghum. Hierarchical cluster analysis was used to explore the different variety of sorghum grouping according to corresponding their SUIS samples as additional information to the output obtained by principal component analysis. Significant genotypic variation was detected in the fourteen elements concentrations in sorghum grains, indicating the possibility to reduce the concentration of toxic elements in grains through breeding approach. It was observed that high tolerance limit of toxic elements was observed in sorghum variety PARC-SV-1.     

Effect of toluene proportion on the yield and composition of oils obtained by supercritical extraction of Moroccan oil shale

Supercritical extraction of Tarfaya's oil shale by toluene revealed that the solvent proportion has a significant effect on the yield and the composition of the obtained oils. The analyses carried out on the recovered oils allowed to establish the optimal operating conditions giving the highest oil yields. In addition, it was observed that these oils contain a large proportion of aromatics compounds.     

Seismic friction base isolation performance using demolished waste in masonry housing

The conversion of large amount of demolished waste into alternate source of building material will contribute not only as a solution to growing waste problem of waste disposal, but also it will conserve the natural resources of other building material and thereby reduce the cost of construction. The present work makes an effort to safe and economic use of recycled mortar as a supplementary material. Conventional and recycled brick prisms were casted with varying percentage of demolished waste added (0%, 10%, 20%, 30%) replacing cement and tested under compression testing machine. As the replacement is increasing, the strength is decreasing. A 1:4 scale single storey brick model was fabricated on shake table for dynamic testing using pure friction isolation system (friction material for coarse dry sand, μ = 0.36). Pure friction isolation technique can be adopted economically in developing countries where low-rise building prevails due to their low cost. The superstructure was separated from the foundation at plinth level, so as to permit sliding of superstructure during severe earthquake. The observed values of acceleration and displacement responses compare fairly with the analytical values of the analytical model except in displacement beyond 2.4 kN. It also concluded that 20% replacement of cement by demolished waste could be safely adopted without endangering the safety of the masonry structures under seismic load.To have an idea that how much energy is dissipated through this isolation, the same model with fixed base was tested and results were compared with the isolated free sliding model and it has been observed that more than 70% energy is dissipated through this pure friction isolation technique. In case of base isolation, no visible cracks were observed up to a table force of 4.25 kN (1300 rpm), whereas for fixed base failure started at 800 rpm and complete bond failure was observed at 1300 rpm.     

Probing Red Blood Cell Membrane Microviscosity Using Fluorescence Anisotropy Decay Curves of the Lipophilic Dye PKH26

Red blood cell (RBC) aggregation and deformation are governed by the molecular processes occurring on the membrane. Since several social important diseases are accompanied by alterations in RBC aggregation and deformability, it is important to develop a diagnostic parameter of RBC membrane structural integrity and stability. In this work, we propose membrane microviscosity assessed by time-resolved fluorescence anisotropy of the lipophilic PKH26 fluorescent probe as a diagnostic parameter. We measured the fluorescence decay curves of the PKH26 probe in the RBC membrane to establish the optimal parameters of the developed fluorescence assay. We observed a complex biphasic profile of the fluorescence anisotropy decay characterized by two correlation times corresponding to the rotational diffusion of free PKH26, and membrane-bounded molecules of the probe. The developed assay allowed us to estimate membrane microviscosity ηm in the range of 100–500 cP depending on the temperature, which paves the way for assessing RBC membrane properties in clinical applications as predictors of blood microrheological abnormalities.     

Induction of apoptosis by a short-chain neuropeptide analog in small cell lung cancer

Small cell lung cancer (SCLC) cells express a variety of neuropeptides which act as autocrine growth factors. Although several neuropeptide analogs have been reported to antagonize SCLC proliferation, the development of these compounds has been limited by their low potency and the cytostatic nature of their effects. In the present study we evaluated the cytotoxic activity of four short-chain substance P analogs (NY3460, NY3238[-pHOPA], NY3238[Phe1], NY3238[Lys5]) against a panel of five SCLC cell lines. NY3460 was the most potent compound in all five SCLC cell lines (IC50 = 2.8-3.7 microM) as assessed by a MTT growth inhibitory assay. NY3238[Phe1] was also relatively active in all cell lines (IC50 = 3.5-11.2 microM), while NY3238[Lys5] and NY3238[-pHOPA] were substantially less active. NY3460 was the only agent to induce an increase in the percentage of cells with subdiploid DNA content suggestive of apoptosis by flow cytometric DNA content analysis. The induction of apoptosis was confirmed by fluorescent microscopy in NCI-H69, NCI-H82, NCI-H446, and NCI-H510 cells after exposure to 5.0 microM NY3460 for 48 h. These findings suggest that NY3460 is a relatively potent cytotoxic inhibitor of SCLC growth, and that short-chain neuropeptide analogs deserve further evaluation as anti-SCLC agents.     

A finite element analysis of temperature in accelerated cutting

Temperature attained during machining has significant effects on the properties of tool, chip and workpiece. It governs the parameters like shear angle, cutting force, tool wear, surface finish etc. Review of literature reveals that hardly any information is available about the analytical determination of the tool-chip interface temperature and the temperature distribution during the accelerated cutting.

This paper presents the temperature analysis of accelerated cutting (i.e. taper turning and facing) as well as longitudinal turning, using the finite element technique. It has been concluded that the temperature distribution within the tool-chip-work system and the average tool-chip interface temperature for the two classes of machining (viz longitudinal turning and accelerated cutting) are not the same, even though the conditions of machining are identical. Further, the average tool-chip interface temperature is lowest in case of facing and highest in case of longitudinal turning.     

Chemical composition, antioxidant and antibacterial properties of the essential oils of Etlingera elatior and Cinnamomum pubescens Kochummen

BACKGROUND: Plant essential oils are widely used as fragrances and flavours. Therefore, the essential oils from the leaves of Cinnamomum pubescens Kochummen (CP) and the whole plant of Etlingera elatior (EE) were investigated for their antioxidant, antibacterial and phytochemical properties. RESULTS: CP and EE were found to contain appreciable levels of total phenolic contents (50.6 and 33.41 g kg^?1 as gallic acid equivalent) and total flavonoid contents (205.6 and 244.8 g kg^?1 as rutin equivalent), respectively. DPPH free radical scavenging activity of CP is superior to EE (P < 0.05) showing IC₅₀ of 77.2 and 995.1 µg mL^?1, respectively. Methicillin‐resistant Staphylococcus aureus (MRSA), Bacillus subtilis, Pseudomonas aeruginosa and Salmonella choleraesuis were tested against CP and EE. Only MRSA was the most susceptible bacteria to CP. GC/MS studies resulted in the identification of 79 and 73 compounds in CP and EE, respectively. The most abundant components of EE included β‐pinene (24.92%) and 1‐dodecene (24.31%). While the major compound in CP were 1,6‐octadien‐3‐ol,3,7‐dimethyl (11.55%), cinnamaldehyde (56.15%) and 1‐phenyl‐propane‐2,2‐diol diethanoate (11.38%). CONCLUSION: This study suggests that the essential oils from Cinnamomum pubescens Kochummen and Etlingera elatior could be potentially used as a new source of natural antioxidant and antibacterial in the food and pharmaceutical industries. Copyright © 2010 Society of Chemical Industry     

Extraction and reliable determination of acrylamide from thermally processed foods using ionic liquid-based ultrasound-assisted selective microextraction combined with spectrophotometry

Acrylamide (AAm) is a carcinogenic chemical that can form in thermally processed foods by the Maillard reaction of glucose with asparagine. AAm can easily be formed especially in frequently consumed chips and cereal-based foods depending on processing conditions. Considering these properties of AAm, a new, simple and green method is proposed for the extraction of AAm from thermally processed food samples. In this study, an ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate, [Bmim][BF₄]) as extractant was used in the presence of a cationic phenazine group dye, 3,7-diamino-5-phenylphenazinium chloride (PSH⁺, phenosafranine) at pH 7.5 for the extraction of AAm as an ion-pair complex from selected samples. Under optimum conditions, the analytical features obtained for the proposed method were as follows; linear working range, the limits of detection (LOD, 3S_b/m) and quantification (LOQ, 10S_b/m), preconcentration factor, sensitivity enhancement factor, sample volume and recovery% were 2.2–350 µg kg^?1, 0.7 µg kg^?1, 2.3 µg kg^?1, 120, 95, 60 mL and 94.1–102.7%, respectively. The validity of the method was tested by analysis of two certified reference materials (CRMs) and intra-day and inter-day precision studies. Finally, the method was successfully applied to the determination of AAm levels in thermally processed foods using the standard addition method.