Direct peptide bioconjugation/PEGylation at tyrosine with linear and branched polymeric diazonium salts

Direct polymer conjugation at peptide tyrosine residues is described. In this study Tyr residues of both leucine enkephalin and salmon calcitonin (sCT) were targeted using appropriate diazonium salt-terminated linear monomethoxy poly(ethylene glycol)s (mPEGs) and poly(mPEG) methacrylate prepared by atom transfer radical polymerization. Judicious choice of the reaction conditions-pH, stoichiometry, and chemical structure of diazonium salt-led to a high degree of site-specificity in the conjugation reaction, even in the presence of competitive peptide amino acid targets such as histidine, lysines, and N-terminal amine. In vitro studies showed that conjugation of mPEG 2000 to sCT did not affect the peptide's ability to increase intracellular cAMP induced in T47D human breast cancer cells bearing sCT receptors. Preliminary in vivo investigation showed preserved ability to reduce [Ca 2+] plasma levels by mPEG 2000-sCT conjugate in rat animal models. © 2012 American Chemical Society

APPLIED ADAPTIVE DYNAMICAL IDENTIFICATION TO THE PREDICTION OF CHEMICAL PROCESS EVOLUTION: A Case Study

A Self Tuning/Adaptive Control Algorithm has been developed and tested. This control has proved to be efficient to maintain the pH effluent of the bench set-up at neutrality. It has been compared with other conventional controllers showing its greater ca-pacity to stand the high changing dynamic of the controlled plant. The minimal control equipment has been chosen in order to approach experimental conditions to industrial real cases. This selection increases the difficulty of the control. Adaptation has proved to be a reliable strategy even under additional constraints. The control goal has been achieved: The developed Self Tuning/ Adaptive Regulator guarantees, in a satisfactory way, pH neutralization without having to use holding stages and even standing in front of hard perturbations

Dynamic Surrogate Modeling for Multistep-ahead Prediction of Multivariate Nonlinear Chemical Processes

This work proposes a methodology for multivariate dynamic modeling and multistep-ahead prediction of nonlinear systems using surrogate models for the application to nonlinear chemical processes. The methodology provides a systematic and robust procedure for the development of data-driven dynamic models capable of predicting the process outputs over long time horizons. It is based on using surrogate models to construct several nonlinear autoregressive exogenous models (NARX) with each one approximating the future behavior of one process output as a function of the current and previous process inputs and outputs. The developed dynamic models are employed in a recursive schema to predict the process future outputs over several time steps (multistep-ahead prediction). The methodology is able to manage two different scenarios: (1) one in which a set of input-output signals collected from the process is only available for training and (2) another in which a mathematical model of the process is available and can be used to generate specific datasets for training. With respect to the latter, the proposed methodology includes a specific procedure for the selection of training data in dynamic modeling based on design of computer experiment (DOCE) techniques. The proposed methodology is applied to case studies from the process industry presented in the literature. The results show very high prediction accuracies over long time horizons. Also, owing to the flexibility, robustness, and computational efficiency of surrogate modeling, the methodology allows dealing with a wide range of situations, which would be difficult to address using first-principles models

Minimization Of Water Consumption And Wastewater Discharge In The Sugar Cane Industry

A comprehensive model has been developed for water minimization and wastewater discharge in the sugarcane industry. As starting point, it is considered that each production unit has a specified consumption of water that must be supplied from the fresh water sources or from one of the sources of regenerated water. In agreement with the concentration of contaminants either the water streams can be reused without treatment, or the best treatment alternative can be selected (taking into consideration its cost and contaminant removal efficiency). The streams are assigned to a treatment system and then the details of the quantities of water that will be reused are calculated. The application of the proposed methodology a case study based on a industrial situation is presented. © 2000 Elsevier B.V. All rights reserved.8C907912Almato, M., Sanmartí, E., Espuña, A., Puigjaner, L., (1998) AIChE Annual Meeting, , MiamiGalán, B., Grossman, I.E., (1999) Comp. Chem. Eng. Sup., pp. S161-S164Pastor, R., Espuña, A., Puigjaner, (1999) AIChE Annual Meeting, , DallasRossiter A. P., (1995) Edit. McGraw-Hill, New YorkWang, I., Smith, R., (1994) Chemical Engineering Science, 49, pp. 3127-314