Some Introductory Remarks

The cells of all contemporary living organisms are surrounded by cell membranes, which normally consist of a phospholipid bilayer, consisting of two layers of lipid molecules, into which various amounts of proteins are incorporated. The basis for the formation of mono- or bilayers is the physicochemical character of the molecules involved these are amphipathic (bifunctional) molecules, i.e., molecules which have both a polar and also a non-polar group of atoms. Examples are the amino acid phenylalanine (a) or the phospholipid phosphatidylcholine (b), which is important in membrane formation. In each case, the polar group leads to hydrophilic, and the non-polar group to hydrophobic character. 

In amphiphilic molecules, the polar, hydrophilic part is known as the head and the non-polar, hydrophobic part the tail of the molecule. Hydrophilic molecules, or parts of molecules, try to interact with polar water molecules, while hydrophobic moieties try to avoid them. 

If amphipathic molecules are mixed with water, three different types of lipid structure are possible the type of aggregate formed depends on the physicochemical conditions and the lipid species involved. The thermodynamic parameter involved is the hydrophobic interaction. 

Micelles are the simplest possible structures. These are spherical entities in which the hydrophobic groups are directed towards the interior. Micelle formation occurs preferentially when the head groups are larger than the hydrophobic groups, as in fatty acids. 

A bilayer forms when two lipid layers come together the hydrophobic groups in the two single layers interact and exclude water. 

AU Please check this change from hydrophilic into hydrophobio. It has been carried out according to the German version. 

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Before discussing the correlation error, we will make some introductory remarks about the Hartree-Fock approximation based on the use of the Slater determinant (Eq. 11.38). We note that, if we... 

Palingenius, Marcellus. The zodiac of life being twelve books concerning human existence, the pursuit of knowledge, and the institutes of ethical law, now for the first time rendered into English prose, with some introductory remarks on Hermetic poetry. London Privately printed, 1896. 299p. 

An appropriate starting point for any discussion of drug transport in the gastrointestinal (GI) tract at the cellular level requires some introductory remarks on the structure and function of GI tissue. As a class of tissue, epithelia demarcate body entry points (skin, eye, respiratory, urinary, and GI organ systems), predisposing a general barrier function with respect to solute entry and translocation. In addi-... 

To describe how the required superposition state [Eq. (7.5)] can be constructed in the laboratory requires some introductory remarks. Note first that Eqs. (7.2) to (7.7) and the E, q, m 0) states are understood to be in the center-of-mass coordinate system and describe the relative translational motion as well as the internal state of A and B. In typical A-B scattering, separating out the center-of-mass motion comes about in a straightforward way. That is, let rA and rB denote the laboratory position of A and B and ikA, Mr denote their laboratory momenta. The relative momentum k, relative coordinate r, center-of-mass momentum K and position Rcm are defined as... 

The body of work that constitutes the metallosalen-catalyzed (Jacobsen-Katsuki) asymmetric epoxidation reaction is far too extensive to be detailed here however, it has been comprehensively reviewed <1996JM087, B-1999M1(11)649, B-2000MI287, 2001COR663, 2005CRV1563>. Rather, after some introductory remarks, we will highlight examples in which ring-fused oxiranes are produced. 

We start with some introductory remarks and the consideration of general framework that can be used for the description of both kinds of multi-component mixtures, i. e., mixtures of neutral particles and mixtures containing charged particles. Let us consider a multi-component fluid in the volume V, containing Na particles in the a-th species. Some of them can be associated with charged particles, and this point will be specified hereinafter. 

After some introductory remarks on the stereochemistry of oxygen and some of the differences between oxygen and sulphur we deal with simple molecules and ions containing oxygen and then with the following topics ... 

It is not the purpose of this monograph to give a detailed discussion into the basic principles of morphology of polymers. Nevertheless, making some introductory remarks here with representative references to the literature seems appropriate, in order to put the individual case studies to be discussed in proper context. 

Some introductory remarks are necessary concerning the thermodynamics of the formation of interfaces and the relation to heterophase polymerization techniques. If two components are completely compatible they do... 

To avoid tiring reiterations when discussing the various diseases some introductory remarks of more general nature may be permitted. 

G. Farrington opened the panel discussion with some introductory remarks on the relevance of the amorphous phase of pol3nneric electrolytes for assuring high conductivity and on the possible routes which may be followed to lower the temperature range of stabilization of this phase. 

I want to thank Mr. Ramon Khanna and Mr. Donatas AkmanaviCius from Springer for their excellent cooperation. The NASA ADS provides a wonderful tool for searching literature and some introductory remarks are based on information found in the WIKIPEDIA—I want to thank the many unknown authors who contribute to that encyclopedia. 

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