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Genesis of chirality and its link to the origin of life continue to intrigue scientists. Chirality also plays an important role in medicine with the advent of chiral drugs and the consequent importance of asymmetric synthesis. The configuration of a chiral molecule gets inverted in its mirror image, as is manifested by (i) sign of specific rotation and (ii) normally, through the absolute configurational notation (R/S). While the first parameter is always true, the second one, that is the mirror image relationship of R and S configurations, called the reflection variance, may not always hold good. In this manuscript, we have highlighted examples of molecules with combinations of central and axial or planar chirality where the mirror image relationship between R and S configurations does not hold. This reflection invariance originates from the CIP rule of R precedes S. Similar reflection invariance can be observed in P or M forms of conformations of some particular molecules with chiral ligands. Proposal to avoid such reflection invariances, has been put forward. An ignorance about the possibility of reflection invariance in enantiomeric molecules can lead to common mistakes about stereoisomeric relationship or reactivity profile.

Humans navigate diverse social relationships and concurrently interact across multiple social contexts. An individual's behavior in one context can influence behavior in other contexts. Different payoffs associated with interactions in the different domains have motivated recent studies of the evolution of cooperation through the analysis of multichannel games where each individual is simultaneously engaged in multiple repeated games. However, previous investigations have ignored the potential role of network structure in each domain and the effect of playing against distinct interacting partners in different domains. Multiplex networks provide a useful framework to represent social interactions between the same set of agents across different social contexts. We investigate the role of multiplex network structure and strategy linking in multichannel games on the spread of cooperative behavior in all layers of the multiplex. We find that multiplex structure along with strategy linking enhances the cooperation rate in all layers of the multiplex compared to a well-mixed population in Prisoners' Dilemma games, provided the network structure is identical across layers. The effectiveness of strategy linking in enhancing cooperation depends on the degree of similarity of the network structure across the layers and perception errors due to imperfect memory. Higher cooperation rates are achieved when the degree of structural overlap of the different layers is sufficiently large, and the probability of perception error is relatively low. Our work reveals how the social network structure in different layers of a multiplex can affect the spread of cooperation by limiting the ability of individuals to link strategies across different social domains. Author summary: People hold simultaneous membership in different social networks where they are engaged in interactions with neighbors, some of whom may be common across all networks while others may be unique to a specific social network. The distinct nature of interactions in different social networks can be modeled as games with distinct benefits. How does the nature of the interactions in different social networks as well as the underlying structure of each network affect cooperation levels in the population? Can linking behaviors across different social networks aid in enhancing cooperation levels across all such networks? We use the framework of repeated games on multiplex network-structured populations to address these questions. We find that linking behaviors can be favorable for increasing cooperation levels in all social networks if there is significant structural overlap between the different networks and perception errors in recalling past actions of interacting neighbors, are low. [ABSTRACT FROM AUTHOR]

The synthesis and chemical reactivity of pyridazinedione-based enediynes are presented. The single-crystal X-ray structures showed similar c,d distances (distance between the acetylenic carbons undergoing covalent connection in Bergman cyclization).

Human RNA‐binding motif 3 protein (RBM3) is a cold‐shock protein which functions in various aspects of global protein synthesis, cell proliferation and apoptosis by interacting with the components of basal translational machinery. RBM3 plays important roles in tumour progression and cancer metastasis, and also has been shown to be involved in neuroprotection and endoplasmic reticulum stress response. Here, we have solved the solution NMR structure of the N‐terminal 84 residue RNA recognition motif (RRM) of RBM3. The remaining residues are rich in RGG and YGG motifs and are disordered. The RRM domain adopts a βαββαβ topology, which is found in many RNA‐binding proteins. NMR‐monitored titration experiments and molecular dynamic simulations show that the beta‐sheet and two loops form the RNA‐binding interface. Hydrogen bond, pi–pi and pi–cation are the key interactions between the RNA and the RRM domain. NMR, size exclusion chromatography and chemical cross‐linking experiments show that RBM3 forms oligomers in solution, which is favoured by decrease in temperature, thus, potentially linking it to its function as a cold‐shock protein. Temperature‐dependent NMR studies revealed that oligomerization of the RRM domain occurs via nonspecific interactions. Overall, this study provides the detailed structural analysis of RRM domain of RBM3, its interaction with RNA and the molecular basis of its temperature‐dependent oligomerization. [ABSTRACT FROM AUTHOR]