Ultrasensitive magnetic particle-based immunosupported liquid membrane assay

A magnetic particle-based immuno-supported liquid membrane assay (m-ISLMA) based on chemiluminescence detection of a horseradish peroxidase-labeled hapten tracer that allows sample cleanup, analyte enrichment, and detection in a single analysis unit has been developed. Antibodies were immobilized on magnetic beads, and their position in the acceptor was controlled by two alternating opposing electromagnetic fields generated by a voltage applied to either of two electromagnets placed below and above the acceptor channel of the supported liquid membrane unit. The influence of antibody bead dilution in the acceptor was investigated and found to follow the ISLM theory, that is improved enrichment and sensitivity with increasing antibody concentration. Two different extraction procedures were investigated: procedure 1 (m-ISLMA-P1), which keeps the antibody beads trapped at the bottom of the acceptor during the entire analysis process; and procedure 2 (m-ISLMA-P2), which keeps the antibody beads dispersed and in motion in the acceptor phase during the extraction process. m-ISLMA-P2 resulted in 2000 times improved enrichment of simazine and a more than 3 orders of magnitude better limit of detection (LOD(10%)) (1.29 x 10(-5) microg L(-1)) than for m-ISLMA-P1 (2.00 x 10(-2) microg L(-1)) and corresponding microtiter plate magnetic particle-based ELISA (m-ELISA, LOD(10%) 1.30 x 10(-1) microg L(-1)). m-ISLMA-P2 and m-ELISA were further applied for the extraction and analysis of simazine-spiked surface water and fruit juice, finding no evidence for matrix influence for the former method; however, indications that trace amounts (nanograms per liter) of simazine or specific cross-reactants were present in both samples.     

NUMERICAL SIMULATION OF TITANIUM ALLOY DRY MACHINING WITH A STRAIN SOFTENING CONSTITUTIVE LAW

In this study, the commercial finite element software FORGE2005®, able to solve complex thermo-mechanical problems is used to model titanium alloy dry machining. One of the main machining characteristics of titanium alloys is to produce a special chip morphology named “saw-tooth chip” or serrated chip for a wide range of cutting speeds and feeds. The mechanism of saw-tooth chip formation is still not completely understood. Among the two theories about its formation, this study assumes that chip segmentation is only induced by adiabatic shear band formation and thus no material failure occurs in the primary shear zone. Based on the assumption of material strain softening, a new material law was developed. The aim of this study is to analyze the newly developed model's capacity to correctly simulate the machining process. The model validation is based on the comparison of experimental and simulated results, such as chip formation, global chip morphology, cutting forces and geometrical chip characteristics. A good correlation was found between the experimental and numerical results, especially for cutting speeds generating low tool wear.     

Grafted 2‐chloroethylphosphonic acid on inorganic supports used as flame retardant for unsaturated polyester resins

Flame retardants (FRs) are used for in protection against fire. Organic–inorganic hybrids could become one of the most promising FR solution in the future. In this paper, the synthesis, the characterization and the use as FRs and filler of grafted titania and alumina with 2‐chloroethylphosphonic acid are presented. These hybrids contain 3.8–3.24% P and have good flame retardance when they are incorporated into unsaturated polyester resins. Alumina treated with 2‐chloroethylphosphonic acid performed better than titania. The advantage of this approach is the use of these hybrid materials as filler and FR, in the same time, and the increase in flame retardancy by synergistic effect between alumina phosphorus and chlorine, for unsaturated polyester resins. Copyright © 2010 John Wiley & Sons, Ltd.     

Molybdenum and Chromium Depletion at Grain Boundary Precipitates Alloy 926

Alloy 926 is a molybdenum-bearing stainless steel and is used in various industrial fields. This material is used as a cladding material for high diameter pipes in oil and gas industry. One opportunity of production of this material is a thermo-mechanical rolling process. Recent studies have shown that an end rolling temperature of 950 °C with subsequent water cooling has comparable corrosion properties with a solution annealed material. The impact of two different quenching and tempering processes on corrosion properties is presented. The microstructure was evaluated with high resolution SEM, and grain boundary precipitates as well as depletion zones were characterized with TEM-EDX line-scans. Isothermal annealing at 760 °C results in formation of Molybdenum rich, Chromium depleted phases. Their microstructure was not clearly detected by electron diffraction, presumably Laves phase is formed. At 900 °C and long term annealing, two s phases are present. One has a similar composition to the above mentioned Laves phase, the other is Molybdenum enriched and Chromium enriched. Thermo mechanically processed materials contains c phases with similar composition. Depletion zones of these phases are quantitatively characterized with respect to width and chemical composition and their impact on corrosion properties is discussed by use of PREN concept.     

Editorial

Neural Computing and Applications -     

K2 Transfection System Boosts the Adenoviral Transduction of Murine Mesenchymal Stromal Cells

Adenoviral vectors are important vehicles for delivering therapeutic genes into mammalian cells. However, the yield of the adenoviral transduction of murine mesenchymal stromal cells (MSC) is low. Here, we aimed to improve the adenoviral transduction efficiency of bone marrow-derived MSC. Our data showed that among all the potential transduction boosters that we tested, the K2 Transfection System (K2TS) greatly increased the transduction efficiency. After optimization of both K2TS components, the yield of the adenoviral transduction increased from 18% to 96% for non-obese diabetic (NOD)-derived MSC, from 30% to 86% for C57BL/6-derived MSC, and from 0.6% to 63% for BALB/c-derived MSC, when 250 transduction units/cell were used. We found that MSC derived from these mouse strains expressed different levels of the coxsackievirus and adenovirus receptors (MSC from C57BL/6≥NOD>>>BALB/c). K2TS did not increase the level of the receptor expression, but desensitized the cells to foreign DNA and facilitated the virus entry into the cell. The expression of Stem cells antigen-1 (Sca-1) and 5′-nucleotidase (CD73) MSC markers, the adipogenic and osteogenic differentiation potential, and the immunosuppressive capacity were preserved after the adenoviral transduction of MSC in the presence of the K2TS. In conclusion, K2TS significantly enhanced the adenoviral transduction of MSC, without interfering with their main characteristics and properties.     

Self-organized TiO2 Nanotube Arrays: Critical Effects on Morphology and Growth

TiO₂ nanotube layers possess a wide range of applications for energy conversion, environmental clean-up, and biomedical implant materials. The formation process of these tube layers is based on a simple but highly optimized anodization process of Ti in a suitable solution. The present work gives a coherent overview on the effect of the key parameters to grow these tube layers. The influence of fluoride content, anodization voltage, water content, and temperature on tube morphology is shown and discussed. The results thus provide the reader with “recipes” and understanding to grow desired TiO₂ nanotube structures, as well as show current limits and open room for improvement for the tailored growth of these structures.