Gated Mesoporous Silica Nanoparticles Using a Double‐Role Circular Peptide for the Controlled and Target‐Preferential Release of Doxorubicin in CXCR4‐Expresing Lymphoma Cells

B‐cell non‐Hodgkin's lymphoma (B‐NHL) is the most frequent malignant lymphoid neoplasm, which has a high degree of relapse and chemoresistance. Thus, strategies to improve currently used therapies are needed. In this context, a new CXCR4‐targeted delivery system is described using mesoporous silica nanoparticles (MSNs) that are loaded with doxorubicin and capped with a derivative of the T22 peptide (P). This design makes full use of the great affinity of the T22 peptide to CXCR4 receptor, which is overexpressed in lymphoma cells. The peptide is able to guide the gated nanoparticle to B‐NHL cells to facilitate MSNs uptake via the CXCR4 receptor. The endocyted P‐capped MSNs are also opened by endosomal proteolytic enzymes to allow intracellular doxorubicin delivery.     

Micropower high current‐drive class AB CMOS current‐feedback operational amplifier

A novel CMOS current‐feedback operational amplifier (CFOA) aimed to low‐power applications is proposed. The use of a compact class AB implementation allows high current‐drive capability and simultaneously very low quiescent power consumption. Measurement results of a fabricated prototype show for an inverting configuration a closed‐loop bandwidth of 1 MHz independent of gain setting, and a slew rate of 2V/µs for a load capacitance of 30 pF and a quiescent power consumption of 264µW. Copyright © 2010 John Wiley & Sons, Ltd.     

Impurity profiling to match a nerve agent to its precursor source for chemical forensics applications

Chemical forensics is a developing field that aims to attribute a chemical (or mixture) of interest to its source by the analysis of the chemical itself or associated material constituents. Herein, for the first time, trace impurities detected by gas chromatography/mass spectrometry and originating from a chemical precursor were used to match a synthesized nerve agent to its precursor source. Specifically, six batches of sarin (GB, isopropyl methylphosphonofluoridate) and its intermediate methylphosphonic difluoride (DF) were synthesized from two commercial stocks of 97% pure methylphosphonic dichloride (DC); the GB and DF were then matched by impurity profiling to their DC stocks from a collection of five possible stocks. Source matching was objectively demonstrated through the grouping by hierarchal cluster analysis of the GB and DF synthetic batches with their respective DC precursor stocks based solely upon the impurities previously detected in five DC stocks. This was possible because each tested DC stock had a unique impurity profile that had 57% to 88% of its impurities persisting through product synthesis, decontamination, and sample preparation. This work forms a basis for the use of impurity profiling to help find and prosecute perpetrators of chemical attacks.     

Effect of the inoculation of the comestible fungus Pleurotus ostreatus on the chemical composition and digestibility of barley straw

The purpose of the present study was to determine whether incubation of the edible mushroom Pleurotus ostreatus in barley straw for 45 or 60 days, proved to be a means of increasing the nutritive value and digestibility of the straw for ruminant animals. In this respect, the following determinations were performed in untreated barley straw (control), and in incubated barley straw with the mushroom strain mentioned previously, for 45 or 60 days: pH, moisture, crude protein, ash, hemicellulose, cellulose, lignin, gross energy and in vitro digestibility of the dry matter. Results showed that crude protein percentage remained constant (p less than or equal to 0.05) in all treatments (means 2.67%), increasing the ash content of the straw incubated for 60 days. The hemicellulose and cellulose percentages diminished significantly (p less than or equal to 0.05) in the straw incubated for 45 or 60 days (16.74, 32.24, 17.43, 32.41% respectively) than in the control straw (24.54, 40.15%). The lignin percentages increased, although not significantly in the straw incubated for 45 or 60 days with respect to the control straw (8.36; 9.10, 9.06%, respectively). Energy values were lower for the straw incubated 45 or 60 days (2.70; 2.74 Kcal/g) than for the control straw (2.80 Kcal/g), without difference in the in vitro dry matter digestibility by incubating the straw for 45 or 60 days with Pleurotus ostreatus and the control (56.04; 52.65; 53.06% respectively). It is concluded that the Pleurotus ostreatus strain used in this study was unable to delignify the straw, because of its lack of fenoloxidases, enzymes which are necessary for lignin biodegradation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Thermal expansion of slag and fly ash from coal gasification in IGCC power plant

Integrated gasification in combined cycle (IGCC) is an electrical power generation system which is characterized to be a clean coal technology different than conventional process in combustible treatment. IGCC process gives rise to inorganic solid wastes in the form of vitreous slag and fly ashes with singular thermal properties. The gasification of the fuel takes place at high temperature and pressure in reducing atmosphere. Under that conditions, gases such as H₂, N₂ or CO, which are the main components of the gas mixture in the gasifier, show a high solubility in the melt and during the cooling remain enclosed in the vitreous slag. When these wastes are afterward thermal treated in oxidizing conditions, two phenomena occur. The development of a crystalline phase by devitrification of the glassy matrix and the releasing of the enclosed gas, which starts at temperatures nearly to the softening point. At higher temperatures the bubbles with increasing kinetic energy tend to ascent with difficult through the viscous liquid phase and promotes an expansive reaction, giving rise to a foam glass-ceramic product. This paper has been focused on the study of thermal expansion in slag and fly ash samples from the ELCOGAS IGCC power plant located in Puertollano (Spain).     

Analysis of thin-slab casting by the compact-strip process: Part I. Heat extraction and solidification

This article reports on an extensive experimental and modeling study undertaken to elucidate the thermal evolution of thin slabs during their passage through the mold and secondary cooling system of a compact-strip process (CSP) caster. In industrial trials covering a wide range of casting conditions, temperature measurements were carried out at (1) the copper plates of an operating mold and (2) the stainless steel frame of an operating grid. Separately, water-flux and heat-flux distributions generated by the several water and air-mist sprays produced by the different nozzles used in the process were determined in the laboratory. The analysis of these pieces of information, together with a detailed consideration of the geometry of the mold and the arrangement of the rolls and spray nozzles, were used to establish appropriate boundary conditions for a two-dimensional, curvilinear-coordinate, unsteady-state heat-conduction model for predicting the solidification rate of thin slabs. The predicted slab surface temperatures show very good agreement with corresponding measured values taken in plant tests at several locations along and across the secondary cooling system. The validation trials involved a wide range of low- and medium-carbon steel grades, casting speeds, slab widths, and secondary cooling strategies. The second part of this article combines the solidification model with a creep model of the shell to yield useful information about design parameters and casting conditions associated with undesirable bulging behavior of the slab after the last support roll, which causes stoppage of the process by slab clogging at the pinch rolls.     

Global manufacturing in the Mexican culture perspective: a case study

The objective of this work is to analyse and provide solutions to the problems encountered during the engineering processes undertaken by global companies established in Mexico. The considerations for this study are not only centred on the engineering work but also on its relation to the culture and the people within which this process takes place. One automobile consortium with a huge assembly plant in Mexico is researched, and a case study is developed for its engineering change process. The time delays in carrying out an engineering change are analysed. Important findings are reported in the areas of software operation, design process, engineers training, teamwork, adaptation to different cultures, technology transfer and language barriers. Concurrent engineering is proposed as a means to gain the time reduction sought by the plant in Mexico. Special attention is recommended for the education of personnel and their preparation for an important organisational change.     

Influence of sepiolite on spherulite growth rate in polyvinylidene fluoride-based polyblends

This work reports on the effects exerted by polymethylmethacrylate, polystyrene and sepiolite on several factors which affect spherulite growth of polyvinylidene fluoride, such as growth rate, nucleation factor and nucleation density. Interpretation of the data obtained will support the discussion on miscibility of binary polyvinylidene fluoride/polymethylmethacrylate and poly-vinylidene fluoride/polystyrene, as well as the miscibilizing effect of sepiolite on both systems.