This review focuses on MR contrast agents that are responsive to a change in physiological environment. The "response" mechanisms are dependent on 6 physicochemical phenomena, including the accessibility of water to the agent, rotational tumbling time, proton exchange rate, electron spin state, MR frequency, or local field inhomogenieties caused by the agent. These phenomena can be affected by ...

Abstract This paper presents the nonlinear dynamic analysis of an ideal two-reactant-two product reactive distillation. The impact of disturbance magnitudes and directions on openloop stability of the system is studied. An analysis of the physicochemical phenomena present in reactive distillation processes that, under certain operational conditions, causes special types of nonlinear behavior is...

Ion pairs (also known as salt bridges) of electrostatically interacting cationic and anionic moieties are important for proteins and nucleic acids to perform their function. Although numerous three-dimensional structures show ion pairs at functionally important sites of biological macromolecules and their complexes, the physicochemical properties of the ion pairs are not well understood. Crysta...

Problem statement: Since the earliest publication on the technique, Reversed-Flow Gas Chromatography (RF-GC) has been used to determine physicochemical properties by measuring the value of one in the presence of another. The method is precise, accurate and simple compared to other conventional techniques. Approach: The experimental setup consists of a small modification of a commercial gas chro...

We have developed a modular pair of laboratory experiments for use both in undergraduate physical chemistry and biochemistry. Both laboratories examine the thermodynamics of the binding of a small molecule, eosin, to the protein lysozyme. The assay for binding is the quenching of lysozyme fluorescence by eosin through resonant energy transfer. In both experiments students measure fluorescence q...

Physical chemistry describes systems in terms of their energy and their boundary conditions. Quantitative knowledge of the future state of a system can be derived from a set of differential equations, relating to the functions defining that system, that provide reasonable estimates of its behavior. This approach, howe v e r, implies first the need to leave aside the individual characteristics o...

There is a widespread agreement that more effective drug delivery vehicles with more alternatives, as well as better active pharmaceutical ingredients (APIs), must be developed to improve the efficacy of microbicide products. For instance, in tropical regions, films are more appropriate than gels due to better stability of drugs at extremes of moisture and temperature. Here, we apply fundamenta...

Protein remote homology detection is one of the most important problems in bioinformatics. Discriminative methods such as support vector machines (SVM) have shown superior performance. However, the performance of SVM-based methods depends on the vector representations of the protein sequences. Prior works have demonstrated that sequence-order effects are relevant for discrimination, but little ...

The shrinking water supply together with our continuously increasing demand for this resource has stimulated a renewed interest in reverse osmosis (RO) as a water treatment unit process. A wider use of RO membranes, however, is impeded by a group of phenomena that lead to permeate flux decline, deterioration of permeate water quality, shortening of membrane life, and thus to a substantial incre...

As indicated by its title, the book ‘Chemistry for Environmental Scientists’ aims at covering a very broad field of knowledge. After a short and general introduction, it is divided in four chapters, namely ‘Chemistry under environmental conditions’, ‘Fundamentals of physical chemistry’, ‘Chemistry of the elements and its [sic] compounds in the environment’ and ‘Chemical processes in the environ...