Brick-and-mortar

Absorption and Drying Towers. Towers are typically carbon steel vessels lined with acid proof brick and mortar and packed with ceramic saddles (see Absorption). More recently, all metal towers having no brick lining have been built from high siHcon stainless steel alloys such as Sandvik SX or Saramet. 

Location is a strategic issue, and the decision where to locate cannot be taken lightly. It is the first decision in the implementation of a project. Upon the decision to proceed, an investment is made which is irreversible. That investment in bricks and mortar cannot physically be transferred to another location if the decision turns out to be wrong. In time, the assets may be realized but probably at much lower values than paid. 

Move over human genome, your day in the spotlight is coming to a close. The genome... contains only the recipes for making proteins... it s the proteins that constitute the bricks and mortar of cells and that do most of the work. 

Stmctural components of cells and tissues are made of proteins that form fibers. These fibrous proteins are the cables, girders, bricks, and mortar of organisms. 

The stratum corneum consists of separated, nonviable, cornified, almost nonpermeable corneocytes embedded into a continuous lipid bilayer made of various classes of lipids, for example, ceramides, cholesterol, cholesterol esters, free fatty acids, and triglycerides [6], Structurally, this epidermis layer is best described by the so-called brick-and-mortar model [7], The stratum corneum is crucial for the barrier function of the skin, controlling percutaneous absorption of dermally applied substances and regulating fluid homeostasis. The thickness of the stratum corneum is usually 10-25 /an, with exceptions at the soles of the feet and the palms, and swells several-fold when hydrated. All components of the stratum corneum originate from the basal layer of the epidermis, the stratum germinativum. 

In an early, quite elaborate model for the diffusion through the stratum corneum, Michaels et al. derived an equation for diffusion through a two-dimensional brick-and-mortar structure [50], In this model, stratum corneum permeability for a given compound depended only on two parameters one was the product of the partition coefficient between the protein and the donor phase /fprot/donor and the diffusion coefficient in the protein phase >Prot the other was the product of the partition coefficient between the lipid and protein phases Aip/prot and the ratio of the diffusion coefficients in the two phases... 

Heisig M, Lieckfeldt R, Wittum G, Mazurkevich G, Lee G (1996) Non steady-state descriptions of drug permeation through stratum comeum. I. The biphasic brick-and-mortar model. Pharm Res 13 421 —426. 

Arumugam P, Xu H, Srivastava S, Rotello VM. Bricks and mortar nanoparticle self-assembly using polymers. Polym Int 2007 56 461-466. 

Highly structured, 3-D nanoparticle-polymer nanocomposites possess unique magnetic, electronic, and optical properties that differ from individual entities, providing new systems for the creation of nanodevices and biosensors (Murray et al. 2000 Shipway et al. 2000). The choice of assembly interactions is a key issue in order to obtain complete control over the thermodynamics of the assembled system. The introduction of reversible hydrogen bonding and flexible linear polymers into the bricks and mortar concept gave rise to system formation in near-equilibrium conditions, providing well-defined stmctures. 

Boal AK, Gray M, llhan F, Clavier GM, Kapitzky L, Rotello VM. Bricks and mortar self-assembly of nanoparticles. Tetrahedron 2002 58 765-770. 

Fig. 2. Nacre of red abalone shell Halitotis refescens), imaged here by transmission electron microscopy (left), has a bricks-and-mortar structure. The bricks are CaCOs (aragonite) platelets, and the mortar is a composite of macromolecules, including structural proteins and polysaccharides, that form a thin film around the platelets. The three-dimensional structure is depicted on the right [23]...

The terms proteomics and proteome were coined by Wilkins et al. in 1994 to describe the entire collection of proteins encoded by genomes in the human organism. Proteomics differs from protein chemistry at this point since it focuses on multiprotein systems rather than individual proteins and uses partial sequence analysis with the aid of databases. Proteins are the bricks and mortar of the cells, carrying out most of the cellular functions essential for survival of the organism. In the cell, proteins... 

Those who stress the in situ methods (Neugebirr. Elcischmann, and Pons) and focus less on the ex situ ones, point to the destruction of the system before observations are made. The solvent in the reactant layer on the electrode, which is held in a certain orientation by the electric field, is similar to that of the bricks and mortar of a house. Removing the potential and destroying the solvent layer is like knocking down the walls of the building. Certainly, some of the contents of the house may be found in the mins, but would it not be better to observe them in their proper setting ... 

The previous chapter described the types of secondary and tertiary structures that are the bricks-and-mortar of protein architecture. By arranging these fundamental structural elements in different combinations, widely diverse proteins can be constructed that are capable of various specialized functions. This chapter examines the relationship between structure and function for the clinically important globular hemeproteins. Fibrous structural proteins are discussed in Chapter 4. 

As aptly put by Doolittle (1985)— If DNA is the blueprint of life, then proteins are the bricks and mortar, ... 

Important changes in the book s content have also been driven by developments in the chemical industry s operating environment. The first edition went to press in early 2001, just as the Internet bubble was about to burst. The chemical industry had just seen itself dismissed as one of those bricks and mortar dinosaurs that would have no place in the new era. This perspective has now changed considerably. The industry s image - in the stock markets, but also in general - has improved significantly in the last five years. 

Association of Chain Drug Stores, 2006). The new millennium also saw the implementation of Internet pharmacy sites, many of which are owned and operated by traditional brick and mortar chain pharmacy corporations. 

The barrier properties of human skin have long been an area of multidisciplinary research. Skin is one of the most difficult biological barriers to penetrate and traverse, primarily due to the presence of the stratum corneum. The stratum cor-neum is composed of comeocytes laid in a brick-and-mortar arrangement with layers of lipid. The corneocytes are partially dehydrated, anuclear, metabolically active cells completely filled with bundles of keratin with a thick and insoluble envelope replacing the cell membrane [29]. The primary lipids in the stratum corneum are ceramides, free sterols, free fatty acids and triglycerides [30], which form lamellar lipid sheets between the corneocytes. These unique structural features of the stratum comeum provide an excellent barrier to the penetration of most molecules, particularly large, hydrophilic molecules such as ASOs. 

On the other hand (and allowing for personal bias), conventional negatives usually do not have this quality. Printing these negatives just seems to be straight ahead bricks-and-mortar work. 

In 1975, Michaels et al.33 presented a conceptual model of the arrangement of corneocytes and lipids in stratum corneum. They envisaged stratum corneum as a brick and mortar structure with the keratin filled corneocytes as bricks and the intercellular lipids as mortar. This model was further explored by Elias and co-worker.34-37 This model does not per se include a structure-function perspective on the barrier but has had a tremendous impact on the research on stratum corneum and its composition, function, and the regulation of homeostasis. 

Recognizing the step-by-step process involved in even the smallest pharmaceutical project can help focus attention in a manner that will result in a successful project. The formal schedule of a well-conceived project will include needs assessment, front-end planning, and preliminary design. It is important that project progress is measured against such a schedule and not just by the visual impact caused by bricks and mortar being installed. 

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