An analysis of Taguchi's on‐line quality monitoring procedure for attributes with diagnosis errors

The on‐line quality monitoring procedure for attributes proposed by Taguchi, Elsayed and Hsiang for processes in which the fraction defective shifts from 0 at some point are examined under the assumption of diagnosis errors. The renewal reward (economic) approach of Nayebpour and Woodall is used to develop a mathematical expression for the long‐run expected cost per item produced and assessment of the optimum inspection interval is discussed. Copyright © 2001 John Wiley & Sons, Ltd.     

Water-soluble derivatives of chitosan as a target delivery system of <Superscript>99m</Superscript>Tc to some organs in vivo for nuclear imaging and biodistribution

Carboxymethyl chitosan, (CMC), and N-lauryl-carboxymethyl chitosan (LCMC), have been prepared as water soluble derivatives of chitosan. These biodegradable chitosan derivatives were characterized and investigated for nuclear imaging and body distribution. They were labeled with ^99mTc to use them as targeted delivery to some organs in vivo for nuclear imaging and to follow their biodistribution within the body. The factors controlling the labeling efficiency have been investigated. The percent labeling yield was determined by using ascending paper chromatographic technique. In vivo biodistribution studies of radiolabeled chitosan derivatives were carried out in groups of female Wistar rats, the body distribution profile in rat was recorded by gamma scintigraphy and the biodistribution of ^99mTc-labeled compounds in each organ was calculated as a percentage of the injected dose per gram of tissue (%ID/g). It has been found that the biodistribution of the two compounds and the pattern of their liver uptake were markedly different. The present study demonstrates a high potential approach for liver imaging using ^99mTc-LCMC. An intriguing finding of this study was that the three samples were excreted rapidly via the kidneys because of the water-soluble nature of chitosan derivatives. This suggests that water-soluble chitosan derivatives are good polymeric carriers for radioactive element that overcomes accumulation in the body. Moreover, the easy and inexpensive availability of chitosan could be beneficial for applications in scintigraphic imaging.     

Prospecting fungal ligninases using corncob lignocellulosic fractions

Microorganisms play an important role in the bioconversion of organic residues and have therefore become promising for obtaining value-added enzymes. In an attempt to take advantage of the by-products and residues of bioconversion, this work sought to use lignocellulosic fractions extracted from corncob as fermentation substrate for ligninase induction by Pleurotus sajor-caju. To obtain the corncob lignocellulosic fractions, biomass was submitted to treatment by alkaline extraction (NaOH 0.75 mol L^?1, 55 °C for 2 h) and organosolv (40% ethanol/water, 185 °C for 20 min). The in natura biomass and lignocellulosic fractions were used as substrates in the subsequent fermentation processes: 2% in natura corncob; 2% cellulose–lignin complex fraction; 2% lignin-enriched fraction; 1% lignin-enriched fraction; and synthetic medium fungal (SMF) as standard. Chemical and physical–chemical analyses indicated the effectiveness of the lignocellulosic extraction process. According to the results, the developed system promoted the induction of ligninases by P. sajor-caju. The enzymatic analysis showed laccase production (768 U L^?1) using the 1% lignin-enriched fraction as substrate. Manganese peroxidase production was 1050 U L^?1 with the use of the 2% lignin-enriched fraction. The presence of lignocellulosic fractions extracted from corncob’s lignin-enriched fraction in the culture medium favored the induction of ligninases in comparison to the use of residue alone.     

Comparative fingerprint analyses of extracts from the root bark of wild Hippocratea excelsa and “Cancerina” by high‐performance liquid chromatography

A simple high‐performance liquid chromatography method was developed for the identification and comparison of quinone‐methide triterpenes in wild Hippocratea excelsa and “cancerina” to establish the chromatographic profile of these compounds in root bark. The essential chromatographic conditions for this method are based on a gradient system with a reversed‐phase column (C₁₈) using proportions of water, methanol, and tetrahydrofuran as mobile phases to correctly separate the signals at 254 and 420 nm and compare the signals to those reported in the literature. The chromatograms exhibit good resolution and precision. Statistical analysis showed that the chromatographic profiles of wild H. excelsa and cancerina do not exhibit significant differences (p0.05) in their area proportions or relative retention times. The method developed in this study is suitable for the identification of the major chemotaxonomic markers of the Celastraceae family and can be used for quality control of this herbal root bark, which has uses today in Mexican folk medicine.     

An HLA-B27 Homodimer Specific Antibody Recognizes a Discontinuous Mixed-Disulfide Epitope as Identified by Affinity-Mass Spectrometry

HLA-B27 homodimer formation is believed to be a hallmark of HLA-B27 associated spondyloarthritides. Recently, we have generated a homodimer-specific monoclonal antibody (HD6) and have demonstrated that HLA-B27 homodimer complexes are present on monocytes of healthy HLA-B27 gene carriers at low levels, with significantly increased levels at active disease. The capability of the HD6 antibody to discriminate between correctly formed HLA-B27 heterotrimers and pathology-associated homodimers is striking and cannot be explained by the primary structure of HLA-B27. We hypothesized that HD6 accesses a unique epitope and used affinity-mass spectrometry for its identification. The HD6 antibody was immobilized on an activated sepharose affinity column, and HLA-B27 homodimer characterized for affinity. The epitope was identified by proteolytic epitope excision and MALDI mass spectrometry, and shown to comprise a discontinuous Cys-203- 257-Cys mixed-disulfide peptide structure that is not accessible in HLA-B27 heterotrimers due to protection by noncovalently linked β2-microglobulin. The epitope peptides were synthesized by solid phase peptide synthesis, and the two monomeric peptide components, HLA-B27(203-219) and HLA-B27(257-273), as well as the homo- and hetero-dimeric disulfide linked combinations prepared. The affinity binding constants K_D towards the antibodies were determined using a surface acoustic wave (SAW) biosensor, and showed the highest affinity with a K_D of approximately 40 nM to the HD6 antibody for the (203-219)-SS-(257-273) mixed disulfide epitope.

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Predictive modeling in a steelmaking process using optimized relevance vector regression and support vector regression

Annals of Operations Research - The existence of contaminants in metal alloys products is the main problem affecting the product quality, which is an important requirement for competitiveness in...     

Morphological and macrostructural studies of dog cranial bone demineralized with different acids

Strong and weak acids were chosen for the bone decalcification process. Demineralization of dog cranial bone was carried out using 0.6 M concentration of either of hydrochloric, lactic or citric acid. Consequent morphologic changes were correlated with the developed chemistry, porosity and structure through XRD and FT-IR of the matrices. The dielectric permittivity, loss angle, relaxation dielectric loss as well as a.c. electrical conductivity as functions of frequency and temperature were measured. Zeta potential was evaluated at physiologic pH and temperature and correlated with the developed structures.The results prove lower dielectric properties of demineralized matrices compared to control and exhibited high dissipation of electric energy with more than one relaxation mechanism. This variation proves that the spectral behavior depended on the nature of the bone matrix which resulted from the phase compositions of bone and its crystallite size. The behavior of the obtained results is attributed to the differences of the demineralizing acids and their consequent actions on the matrices, i.e., the differences in the materials.