Correct human cardiac nomenclature

Proper heart’s nomenclature is very important in daily clinical practice and research studies, andwhen it is consistent, it can facilitate better communication between different medical specialists. Thegeneral rule of the anatomy is to describe organs and their structures in attitudinally correct position.However, the use of the old-fashioned Valentine position (where the heart is described as if it werestanding on its apex) is still in use to describe important cardiac structures. Upon closer analysis, all main chambers of the heart and their associated subcomponents have mislabeled structures that should be renamed. In this article we aimed to emphasize the limitations of Valentinian nomenclature, presentproper anatomical names of the most important heart’s structures and advocate to change certain mis-labeled anatomical structures. Attitudinally correct designations presented in this study will benefit allmedical specialties, and they will reinforce the importance of consistent orientational naming. Correctnaming of heart’s structures will also help improve communication between different medical specialists

Parallel Charge-Transfer Mechanisms Allow for Diversifying the Choices for Photoredox Catalysts

Photochemistry provides access to reactive intermediates that are often inaccessible by any other means. Most organic molecules, however, are colorless ultraviolet absorbers. Therefore, photocatalysts absorbing in the visible spectral region are essential for transferring the required energy and charges to make challenging chemical transformations possible. A selection of a photocatalyst for driving oxidative or reductive reactions is crucial and is commonly based on their electrochemical potentials as well as the potentials of the starting materials. This selection, however, sometimes proves limiting and misleading, especially when the thermodynamic driving forces of the charge-transfer steps are relatively small. Here, we show that porphyrinoids with differences in their electrochemical potentials exceeding 0.5 V can photocatalyze the same model reaction of N-alkyl-2,4,6-triphenylpyridinium salt with alkynyl p-tolylsulfone to form the same alkylated alkynyl product in similar yields. Our studies reveal that switching between parallel reaction pathways makes the attainment of these conversion efficiencies possible. Electron-rich catalysts drive the formation of alkyl radicals principally via a photoinduced electron transfer to the pyridinium ion and a sequential hole transfer recovers their ground states, i.e., PET-HT mechanism. Conversely, a photoinduced hole transfer dominates the initial formation of the reduced forms of electron-deficient porphyrins that then transfer electrons to the pyridinium salt to release the same alkyl radicals, i.e., PHT-ET mechanism. This discovery demonstrates a paradigm where reaction mechanism adjust to the electronic properties of catalysts and opens doors for transformative diversification and broadening of the applicability of photochemical transformations.<br /

Mutual arrangements of coronary blood vessels within the right atrial appendage vestibule

Background: The aim of our study was to investigate the presence and mutual relationships of coronary vessels within the right atrial appendage (RAA) vestibule. Methods: We examined 200 autopsied hearts. The RAA vestibule was cross-sectioned along its isthmuses (superior, middle, and inferior). Results: The right coronary artery (RCA) was present in 100% of the superior RAA isthmuses but absent in 2.0% of hearts within the middle isthmus and in 6.5% of hearts within the inferior RAA isthmus. Its diameter was quite uniform along the superior (2.6 ± 0.8 mm), middle (2.9 ± 1.1 mm), and inferior (2.7 ± 0.9 mm) isthmuses (p = 0.12). The location of the RCA varied significantly, and it was sometimes accompanied by other accessory coronary vessels. In all the isthmuses, the RCA ran significantly closer to the endocardial surface than to the epicardial surface (p < 0.001). At the superior RAA isthmus, the artery was furthest from the right atrial endocardial surface and this distance gradually decreased between the middle RAA isthmus and the inferior RAA. Conclusions: This study was the most complex analysis of the mutual arrangements and morphometric characteristics of coronary blood vessels within the RAA vestibule. Awareness of additional blood vessels within the vestibule can help clinicians plan and perform safe and efficacious procedures in this region