Generalized quaternionic involute-evolute curves in the Euclidean four-space E4

In this paper, a new type of quaternionic partner curves is defined as generalized quaternionic involute-evolute curves or $(0,2)$-quaternionic involute– $(1,3)$-quaternionic evolute curves in the four-dimensional Euclidean space. The relations between the Frenet frames and curvatures of the quaternionic involute-evolute curve couple are introduced. Moreover, the necessary and sufficient conditions for a quaternionic curve to have a generalized involute are obtained.     

Nanoerythrocyte Membrane–Enveloped ROS-Responsive 5-Aminolevulinic Acid Prodrug Nanostructures with Robust Atheroprotection

The development of smart nanoagents that can respond to a specific stimulus has gained remarkable interest for treating various kinds of diseases, including atherosclerosis. On the other hand, a cell camouflaging strategy has been considered as a pivotal factor to improve the delivery stealthiness, biocompatibility, and biodegradability of nanocarriers, resolving the shortcomings of PEGylation. In this study, reactive oxygen species (ROS)-responsive 5-aminolevulinic acid (ALA) prodrug nanostructures (ROSELLA) encapsulating rapamycin (RAP) are blended with nanoerythrocyte membranes to construct red blood cell membrane (RBCM)/RAP@ROSELLA. These nanoagents are designed to be able to escape the biological barriers, accumulate in atherosclerosis lesions, and enhance the release of drugs in the intracellular milieu due to the magnification of hydrogen peroxide (H₂O₂). In vitro study proves its superior ability to inhibit the proliferation of macrophages and vascular smooth muscle cells. In vivo developmental toxicity further confirms that no significant systematic toxicity is induced by RBCM/RAP@ROSELLA, implying its favorable biocompatibility, which has potential for precise nanomedicine to combat atherosclerosis.     

Review on asymmetric synthetic methodologies for chiral isoquinuclidines; 2008 to date

Isoquinuclidines constitute the central structural nucleus of numerous biologically active natural products, for example, iboga alkaloids such as ibogamine and catharanthine as well as non-indole-containing alkaloids such as the dioscorine and the cannivonines. Furthermore, in medicinal and pharmaceutical chemistry, the isoquinuclidine core is commonly employed as a rigid azabicyclic scaffold, thus providing significant precursors in the synthesis of numerous valuable alkaloids. Summarizing well-organized approaches to access the chiral isoquinuclidine structural centerpiece signifies a significant endeavor not only for developing biologically active natural products but also enhancing biological researches that can lead to possible drug discovery. Over time, the values and methodologies for the asymmetric synthesis of chiral isoquinuclidines are increasing; hence to advance asymmetric synthesis, this review combines and discusses the pros and cons of each synthesis techniques from 2008. This review should be helpful for promoting further developments of asymmetric synthetic methodologies and for medicinal chemistry.     

Ring-opening reactions of oxetanes: A review of methodology development and synthetic applications

Ring-opening reactions of oxetanes yield important functionalized products depending upon the nature of nucleophiles as well as substitution pattern on the oxetane ring. Ring opening of oxetanes can be carried out under a variety of reaction conditions. In this review article, an up-to-date overview of major synthetic methodologies involved in the ring opening of oxetanes as well as their synthetic applications has been presented.