Easy to use and rapid isolation and detection of a viral nucleic acid by using paramagnetic microparticles and carbon nanotubes-based screen-printed electrodes

A method that is easy to use, rapid, with a low cost of detecting viral nucleic acid in a biological sample represents the essential tool in targeted therapy. In this study, we report the use of paramagnetic microparticles covered by streptavidin and modified by an oligonucleotide probe with a specific viral sequence labeled by biotin to detect human immunodeficiency virus (HIV) and influenza virus subtype H5N1. The viral nucleic acids were primarily detected by adsorptive transfer stripping technique coupled with square wave voltammetry using carbon paste, hanging mercury drop or carbon nanotubes-based screen-printed working electrodes. Detection limits were estimated for both sequences down to picograms per 3 μl. To isolate the viral sequences, paramagnetic microparticles covered with biotin-labeled oligonucleotides were used. We calculated the yield of isolation for H5N1 and/or HIV sequences, which was defined as “isolated concentration of viral nucleic acid sequence”/“given viral nucleic acid sequence” × 100. We estimated the yield for both sequences as 59%. Moreover, we studied the influence of human serum, dsDNA and non-complementary sequence of nucleic acids on isolation of viral nucleic acids. We also used carbon nanotubes-based screen-printed electrodes coupled with micro-flow instrument to detect viral nucleic acids. We were able to isolate and detect nanogram amounts of nucleic acids.     

Contribution of agro‐waste material main components (hemicelluloses,cellulose, and lignin) to the removal of chromium (III) from aqueous solution

BACKGROUND: Agro‐waste materials can be used as biosorbents of heavy metals in aqueous solution. However, it is necessary to further study the contribution of agro‐waste materials components (i.e. hemicelluloses, cellulose, and lignin) to the heavy metal ions removal from aqueous solution to better understand the biosorption mechanism, and also based on the biosorbents main components, to predict their potential to remove heavy metals. RESULTS: Cellulose is contained in major proportion (greater than 46%) in the agro‐waste materials reported herein compared with hemicelluloses (from 12% to 26%), lignin (varying from 3% to 10%), and other compounds (22% to 30%) that were removed after the neutral detergent fiber procedure. The identified functional groups in agro‐waste materials and their fractions included hydroxyl, carboxyl, and nitrogen‐containing compounds. Lignin contributed in higher proportion than hemicelluloses to Cr (III) adsorption capacity in both sorghum straw and oats straw. On the other hand lignin was the main fraction responsible for Cr (III) adsorption in agave bagasse. CONCLUSION: Hemicelluloses and lignin were the main contributors to Cr (III) removal from aqueous solution, and cellulose contained in the agro‐waste adsorbents studied did not seem to participate. Copyright © 2009 Society of Chemical Industry     

Effect of blend ratio and elongation flow on the morphology and properties of epoxy resin‐poly(trimethylene terephthalate) blends

The effect of processing conditions on the morphology of polymer blends is a topic of tremendous practical interest especially for thermoset–thermoplastic blends. The effect of blend ratio and the nature of the flow field (shear flow vs. elongation flow) on the morphology is followed here using blends of diglycidyl ether of bisphenol A (DGEBA)‐poly(trimethylene terephthalate) (PTT). Morphology of the blends prepared by the conventional melt mixing technique is compared with that prepared by using an elongation mixer (RMX device invented by Muller et al.). The blends prepared by the elongation mixer showed excellent transparency and higher storage modulus at room temperature than the conventional mixer. In the case of samples prepared by the RMX device T_g of the epoxy phase has been shifted to lower temperatures indicating a molecular level mixing between PTT and DGEBA. However the conventional melt mixed samples showed only a marginal shift in T_g to low temperatures indicating that the system is not as miscible as that prepared by the RMX device. The use of RMX device for thermoset–thermoplastic blends is novel and no work has been reported in this relation. The properties of the blends were strongly affected by the composition and the crystallization of the semicrystalline PTT phase. POLYM. ENG. SCI., 55:1679–1688, 2015. © 2014 Society of Plastics Engineers     

An adsorptive transfer technique coupled with brdicka reaction to reveal the importance of metallothionein in chemotherapy with platinum based cytostatics

The drugs based on platinum metals represent one of the oldest, but also one of the most effective groups of chemotherapeutic agents. Thanks to many clinical studies it is known that resistance of tumor cells to drugs is a frequent cause of chemotherapy failure. With regard to platinum based drugs, multidrug resistance can also be connected with increased expression of low-molecular weight protein metallothionein (MT). This study aimed at investigating the interactions of MT with cisplatin or carboplatin, using the adsorptive transfer technique coupled with differential pulse voltammetry Brdicka reaction (AdTS DPV Brdicka reaction), and a comparison of in vitro results with results obtained in vivo. The results obtained from the in vitro study show a strong affinity between platinum based drugs and MT. Further, we analyzed extracts of neuroblastoma cell lines treated with cisplatin or carboplatin. It is clear that neuroblastoma UKF-NB-4 cisplatin-resistant and cisplatin-sensitive cell lines unlikely respond to the presence of the platinum-based cytostatics cisplatin and carboplatin. Finally, we determined the level of MT in samples from rabbits treated with carboplatin and patients with retinoblastoma treated with the same drug.