Virtual dissection

Rapamycin (sirolimus), a macrolide antibiotic, has been used recently in organ transplantation for its potent immunosuppressive actions by inhibiting both cytokine mediated and growth factor mediated proliferation of smooth muscle cells and lymphocytes [55, 56]. In the RAVEL trial of non-acute single vessel lesions, the Sirolimus-eluting stent was compared to bare metal stent (BMS) in a 1 1 fashion [57]. One-year major adverse cardiovascular events and 6 month neointimal proliferation as assessed by late luminal loss (-0.01 0.33 mm in Sirolimus stent versus 0.80 0.53 mm in BMS) were improved. The Sirolimus-eluting stent thus virtually eliminated in-stent restenosis with no evidence of edge effect, dissection, or in-stent thrombosis. 

This philosophy has had a profound effect on the methods of inquiry in virtually every field of human endeavour. It has guided scientists to pursue the pattern of study dissect, identify, classify, and dissect further. The logical extension of this approach is to search for the ultimate, ahistoric particle as the fountainhead of creation the basic ingredient with which to model and understand the universe. This is the addition/unification sequel to reductionism, whereby parts are then reassembled into additive models. 

The transition state of a reaction is difficult to study because it is so short-lived. To understand enzymatic catalysis, however, we must dissect the interaction between the enzyme and this ephemeral moment in the course of a reaction. Complementarity between an enzyme and the transition state is virtually a requirement for catalysis, because the energy hill upon which the transition state sits is what the enzyme must lower if catalysis is to occur. How can we obtain evidence for enzyme-transition state complementarity Fortunately, we have a variety of approaches, old and new, to address this problem, each providing compelling evidence in support of this general principle of enzyme action. 

Virtually over its entire extension, the continental slope of the Black Sea is dissected by numerous faults and underwater canyons. These canyons, confined to tectonic dislocations (fracture zones or grabens), are later transformed by turbidity flows, which use them as channels for the transport of mineral particulate matter from the near-shore zone to the foot of the continental slope. At the places of discharge of turbidity flows, alluvial fans are formed, which may be cut by runoff channels [10]. 

Fragment-based programs employ molecular building-blocks from a fragment database that contains virtual synthons from commercially or synthetically available compounds or from virtual retrosynthetic decomposition of a compound database. The bonds cleaved during the retrosynthetic dissection process are not necessarily the ones that will be made during the actual synthesis. For example, the formation of a tertiary amine in the reaction shown in Figure 7.2 can be performed in different ways. Typically, retrosynthesis... 

Despite its apparent simplicity, on the basis of an extraordinarily large amount of experimental data, the reaction catalyzed by dihydrofolate reductase has been dissected into a complex series of reaction steps. A comparison between the E. coli enzyme and an R-plasmid-coded dihydrofolate reductase involved in trimethoprim resistance indicates that the chromosomal enzyme has evolved to a virtually perfect catalytic process. ... 

Fig. 7.8a,b. Dissected view tools of the colon generated with software from different vendors. Barco/Voxar Colonscreen (a) and GE Medical Systems Virtual dissection (b)... 

Bernardo A, Preul MC, Zabramski IM, Spetzler RF (2003) A three-dimensional interactive virtual dissection model to simulate transpetrous surgical avenues. Neurosurgery 52 499-505... 

Wiet GJ, Stredney D, Sessanna D, Bryan JA, Welling DB, Schmalbrock P (2002) Virtual temporal bone dissection an interactive surgical simulator. Otolaryngol Head Neck Surg 127 79-83... 

When using a primary 3D interpretation technique, navigation should be performed in both directions to maximise polyp detection unless the image is represented in such a way that the eye can observe behind obstacles (e.g. folds) as is the case with the virtual dissection or unfolded cube techniques that will be discussed in the next Chapters 19 and 20. The 3D method may be more accurate than 2D interpretation, especially for smaller lesions, but it is more time-consuming (Dachman et al. 1998 Macari et al. 2000 Rex et al. 1999). 

Techniques of Virtual Dissection of the Colon Based on Spiral CT Data... 

Different steps have to be undertaken to obtain a virtual dissection of the colon. After MRDCT scanning, the reconstructed, overlapping slices were... 

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