Structural Reciprocity: Critical Overview and Promising Research/Design Issues

Reciprocity is a structural principle that has fascinated designers and builders throughout the world since ancient times. Despite the topic's having been studied by various academics, designers and researchers, a critical overview of the references is still missing, as is an outline and discussion of the current and future promising research/design issues. Further, no single text provides an exhaustive definition of the principle of structural reciprocity and it must be critically reconstructed from several different sources. This paper aims to fill in these gaps, providing a complete and annotated list of references, in which historical examples, as well as patents, research articles and terminological issues are discussed. A consistent definition of structural reciprocity is also proposed, and the promising developments of such a principle are outlined in order to guide designers and researchers in the futur

Mechanical versus humoral determinants of brain death-induced lung injury - Fig 7

<p><b>Relative lung mRNA expression of intercellular adhesion molecule (ICAM) and vascular cell adhesion molecule (VCAM)-1</b> at baseline, one (BD + 1 hour) and five (BD + 5 hours) hours after Cushing reflex in the placebo-pretreated brain death (BD group; n = 11; red bars) and in the methylprednisolone-pretreated brain death (BD + Corticosteroids group; n = 8; blue bars) groups. Values are expressed as mean ± SEM. * p<0.05 BD versus BD + Corticosteroids; || p<0.05 Base versus BD + 1 hour, ** p<0.05 Base versus BD + 5 hours in the BD + Corticosteroids group.</p

Enzymology of mammalian DNA methyltransferases

DNA methylation is currently one of the hottest topics in basic and biomedical research. Despite tremendous progress in understanding the structures and biochemical properties of the mammalian DNA nucleotide methyltransferases (DNMTs), principles of their regulation in cells have only begun to be uncovered. In mammals, DNA methylation is introduced by the DNMT1, DNMT3A, and DNMT3B enzymes, which are all large multi-domain proteins. These enzymes contain a catalytic C-terminal domain with a characteristic cytosine-C5 methyltransferase fold and an N-terminal part with different domains that interacts with other proteins and chromatin and is involved in targeting and regulation of the DNMTs. The subnuclear localization of the DNMT enzymes plays an important role in their biological function: DNMT1 is localized to replicating DNA via interaction with PCNA and UHRF1. DNMT3 enzymes bind to heterochromatin via protein multimerization and are targeted to chromatin by their ADD and PWWP domains. Recently, a novel regulatory mechanism has been discovered in DNMTs, as latest structural and functional data demonstrated that the catalytic activities of all three enzymes are under tight allosteric control of their N-terminal domains having autoinhibitory functions. This mechanism provides numerous possibilities for the precise regulation of the methyltransferases via controlling the binding and release of autoinhibitory domains by protein factors, noncoding RNAs, or by posttranslational modifications of the DNMTs. In this chapter, we summarize key enzymatic properties of DNMTs, including their specificity and processivity, and afterward we focus on the regulation of their activity and targeting via allosteric processes, protein interactors, and posttranslational modifications