Embedding techniques

The simple catalyst embedding technique has been applied to ethylene polymcaization in slurry In this technique, active catalytic components are embedded into styrene polymer matrix. The resulting polyethylene shows better morphology and higher bulk density than those produced by homogeneous catalyst. No activity loss was also observed with the... 

Shi S-R, Liu C, Perez J, et al. Protein-embedding technique a potential approach to standardization of immunohistochemistry for formalin-fixed, paraffin-embedded tissue sections. J. Histochem. Cytochem. 2005 53 1167-1170. 

STANDARD REFERENCE MATERIAL PROTEIN-EMBEDDING TECHNIQUE AND DESIGN OF BAR CODE... 

This electrostatic embedding strategy has been successfully applied in a variety of QMCF MD simulations of hydrated systems (38 3). The embedding technique in connection with improvements of the QM/MM coupling leads to a significantly increased accuracy of the description of the systems compared to conventional QM/MM MD procedures. The QMCF framework is compatible with any affordable quantum chemical level and will enable the application of correlated ab initio methods (e.g., MP/2) in the near future. 

To prepare tissue, 2-3 mm slices are removed as quickly as possible into ice-cold acetone and left on ice for 4-6 h. (Less than 4 h can result in incomplete penetration of fixative and subsequent formation of ice crystals.) Samples are then stored m a -20°C freezer until they can be processed using routine paraffin embedding techniques. 

At Kraft Foods, we have had occasion to use this rapid sandwich technique on unembedded cream cheese, viscous dressing and ice cream mix, looking for xanthan or guar/LBG. We have also probed sections of embedded materials for xanthan. In other words, the rapid and embedded techniques are fully complementary. 

We report a simple and direct pre-embedding technique for processing scarce biological specimens for LM and EM. It is based on pre-embedding the samples in BSA and BA, cross-linked and polymerized. The technique is compatible with a broad range of LM and EM protocols and procedures. 

We report a simple and direct pre-embedding technique for processing scarce biological specimens for LM and EM the samples are pre-embedded in BSA and BA, cross-linked and polymerized. The technique is compatible with a broad range of LM and EM protocols and procedures. It is applicable to tissues and cells, prepared as pellet or suspension. The technique represents an improvement over others, like the ability to visualize the samples once pre-embedded and a better resistance to histological processing. It allows a more efficient and reproducible analysis of the samples by LM and EM. The technique is... 

Embedding techniques at various levels have been suggested to close the gap between the cluster and the periodic treatment. A physical approach to the electronic structure problems of solids and surfaces contrasts sharply with the intuition of chemists that local interactions dominate the properties of surfaces and adsorption complexes. Hence, it is very desirable to replace the infinite solid, which is very difficult to treat quantum-chemically, by finite models of the sites of interest. In this way it is easy to describe a local site as cluster having a relatively small number of atoms which interact with a potentially infinite number of surrounding atoms through, for example, the Madelung potential which is treated as perturbation.26,44 These lead to terms such as... 

Thus, all force components resulting from the embedding technique can be obtained conveniently from the quantum mechanical calculation. 

An alternative solution to this problem is to apply the force obtained by Coulomb s law to both the QM and the MM counterparts, but then the embedding of MM charges has to be discarded as otherwise the Coulombic contributions for the QM atoms would be treated twice. On the other hand the improved description of the electron density makes the embedding technique a desirable feature. Therefore, an embedding scheme has to be sought which on the one hand allows the inclusion of the point charges to improve the quantum mechanical description, but on the other hand does not show any inconsistencies in the derivation of forces or with respect to momentum conservation. 

To derive an embedding scheme compatible with an application in a periodic environment the properties of the embedding technique and the QM calculations have to be recalled. Partial charges are included in the Hamiltonian as outlined in the... 

Potting involves casting a plastic in a shell that is a container representing a mold cavity. Within the plastic a product could be embedded. Potting is similar to encapsulation except that the shell is not separated from the finished product. It is an embedding technique in which the shell and plastic remains consolidated. 

Use of embedding techniques. With these, we attempt to remedy some of the deficiencies of the cluster method by including an approximate representation of the surrounding lattice using interatomic potential methods. There are several variants of the approach, but if implemented properly, such methods can overcome some of the difficulties of PBC methods, for example, catalytic reactions. A recent example of the use of this method is given in Section 3.3. 

With this embedding technique, one selects a representative cluster representing a solid, and embeds the cluster in a surrounding portion of the crystalline lattice, usually consisting of several coordination shells. The corresponding Hamiltonian reads... 

---