Long-term potentiation definition

The question whether lutein and zeaxanthin can contribute to lowering the risk for AMD cannot be answered unequivocally by epidemiological studies. Only randomized controlled trials (RCTs) during the course of which xanthophylls are supplemented in a double-blind, placebo-controlled, and randomized manner, and in which results are evaluated according to clear predefined efficacy criteria (Seddon and Hennekens 1994) have the potential to provide definitive answers. The specific long-term time-course and intricate nature of AMD make the design of such studies difficult, however. 

Appendix B reviews some important animal studies of cholinesterase reactivator chemicals. The extensive literature reviewed offers little definitive information with which to project possible long-term effects or delayed sequelae in human subjects tested at Edgewood. These compounds have a short biologic half-life of 1 to 3 h. However, no chronic studies were found. Consequently, the carcinogenic potential of cholinesterase reactivators remains... 

Schematic representation of the hematopoietic cascade in mice and human (hum). All the cells of the hematopoietic system are positive for antigen CD45. Based on this, the dynamics of surface antigen expression along development of different mature cells derived from the hematopoietic stem cell system can be observed. Rounded arrows indicate self-renewal potential. Smooth thinner arrows indicate directions of cellular differentiation. The identification of CDs (clusters definition) and other antigen cell markers are listed in the glossary. (LT-HSC - long term hematopoietic stem cell ST-HSC - short term hematopoietic stem cell MPP - multipotent progenitor CLP - common lymphoid precursor CMP - common myeloid precursor GMP - granulocyte-monocyte precursor MEP - megacaryocyte-erythrocyte precursor T - T lymphocyte B - B lymphocyte NK - natural killer cell DC - dendritic cell).

The precatheterization (venous or arterial) skin preps are very similar to the preoperative skin preps in terms of efficacy requirements. And there is a definite thrust in the industry for long-term precatheterization insertion preps—those that remain effective for over 24 hours [22]. A substantial, yet underappreciated potential exists for bloodstream infections originating at the vascular access site [25]. More than one-half of all epidemics of nosocomial bacteremia or candide-mia are caused by vascular access of some type, and these are, for the most part, preventable. 

The solid/gas interface was traditionally studied with respect to adsorption and catalysis. Here the assertion that the Bronsted definition of acidity is a particular case of the Lewis definition is neither obvious nor even helpful. It suffices to say that many reactions in heterogeneous catalysis require specifically the presence of either Bronsted or Lewis acidic (or basic) sites, and the reaction mechanisms depend on the nature of the surface site. A long-term goal of surface studies for the characterization of solid catalysts was to distinguish and quantify the number of Bronsted or Lewis sites with potential catalytic activity for gas-phase reactants. For that reason, when discussing the acid-base behavior of solid surfaces, it is no longer possible, nor desirable, to adopt the viewpoint that subsumes Bronsted acid-base properties in the more general Lewis definition. 

---