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As cardiovascular computed tomography (CCT) practice evolves, the demand for specialists continues to increase. However, CCT training remains variable globally with limited contemporaneous data to understand this heterogeneity. We sought to understand the role of CCT globally and the training available to underpin its use. We performed two consecutive surveys of cardiology and radiology physicians, two years apart, utilizing the Society of Cardiovascular Computed Tomography (SCCT) website, weblinks, social media platforms, and meeting handouts to maximize our response rate. We compared United States (US)-based vs. international responses to understand global similarities and differences in practice and training in the surveys. 235 respondents (37% trainees and 63% educators/non-trainees) initiated the first survey with 174 (74%) completing the core survey, with 205 providing their work location (114 US and 91 international). Eighty-four percent (92/110) of educator respondents stated a need for increased training opportunities to meet growing demand. Dedicated training fellowships are heterogenous, with limited access to structural heart imaging training, despite structural scanning being performed within institutions. The lack of a standardized curriculum was identified as the main obstacle to effective CCT learning, particularly in the US, with web-based learning platforms being the most popular option for improving access to CCT training. 148 trainees initiated the second survey with 107 (72%) completing the core components (51% North America, 49% international). Only 68% said they would be able to meet their required CCT education needs via their training program. Obstacles in obtaining CCT training again included a lack of a developed curriculum (51%), a lack of dedicated training time (35%), and a lack of local faculty expertise (31%). There was regional variability in access to CCT training, and, in contrast to the first survey, most (89%) felt 1:1 live review of cases with trained/expert reader was most useful for improving CCT training alongside formal curriculum/live lectures (72%). There is a need to expand dedicated CCT training globally to meet the demand for complex CCT practice. Access to CCT education (didactic and 1:1 case-based teaching from expert faculty), implementation of recently published global training curricula, and increased teaching resources (web-based) as an adjunct to existing experiential learning opportunities, are all deemed necessary to address current educational shortfalls. Table of Contents Summary: Serial surveys were performed by the Society's FiRST Committee members and Future Leaders Program participants to understand the contemporary nature of CCT use and education available to trainees to underpin its utilization. Despite the validation and growth of CCT in recent years, ongoing obstacles to CCT training identified were lack of 1) developed CCT curriculum, 2) CCT scanner/training time, and 3) faculty expertise at local institutions. This article serves as a continued call to action to update and modernize the educational CCT curriculum around the world. [ABSTRACT FROM AUTHOR]

Trivalent chromium has been proposed to be transported in vivo from the bloodstream to the tissues via endocytosis by transferrin (Tf), the major iron transport protein in the blood. While Cr(III) loss from the Tf/Tf receptor complex after acidification to pH 5.5 has recently been shown to be sufficiently rapid to be physiologically relevant, the released Cr(III) still must exit the endosome during the time of the endocytosis cycle (circa 15 min). Cr(III) binds too slowly to small ligands such as citrate or ascorbate, or even EDTA, for such complexes to form and be transported from the endosome, while no trivalent ion transporters are known. However, the apo form of the peptide low-molecular-weight chromium-binding substance (LMWCr) can remove Cr(III) from Cr(III) 2 -Tf at neutral pH, albeit slowly, and LMWCr is known to be transported from cells after binding Cr(III), although the transporter is not known. LMWCr subsequently carries Cr(III) to the bloodstream ultimately for removal from the body in the urine. The rate of binding of Cr(III) to apoLMWCr was significantly enhanced in the presence of the Tf/Tf receptor complex. These results suggest that apoLMWCr may function to bind Cr(III) released in the endosomes for ultimate removal from the body as part of a Cr(III) detoxification process. The rate of binding of Cr(III) to low-molecular-weight chromium-binding substance (LMWCr) is greatly enhanced in the presence of the transferrin/transferrin receptor complex at pH 5.5. LMWCr may function to bind Cr(III) released in the endosomes for ultimate removal from the body in the urine. [Display omitted] • A function is identified for low-molecular-weight chromium-binding substance (LMWCr). • LMWCr accelerates the loss of Cr(III) from transferrin upon acidification. • Transferrin/transferrin receptor complex accelerates binding of Cr(III) to LMWCr. • LMWCr may function to bind Cr(III) released in endosomes. • ATP is not an ionophore for Cr(III) release from endosomes. [ABSTRACT FROM AUTHOR]

Abstract: Substituted vinylcyclopropanes are prepared through a ruthenium-catalyzed, tandem three-component coupling between an olefin, alkyne, and diazoester. Grubbs’ 2nd generation (NHC) ruthenium complexes in the presence of ethylene effect a stereoselective enyne-cross metathesis between alkynes and olefins to generate 1,3-substituted dienes. The slow introduction of diazoacetates to this reaction mixture then allows for the regioselective cyclopropanation of the resulting diene. When the olefin reaction partner is just ethylene (i.e., R′=H), the tandem process is less efficient. In this case, the byproducts provide unique insight into possible catalyst decomposition pathways. [Copyright &y& Elsevier]

Abstract: The DNA binding efficacy and preferred mode of binding of a series of rhodamine-related chalcogenoxanthylium dyes was investigated by isothermal titration calorimetry (ITC) using ctDNA, [poly(dCdG)]2 and [poly(dAdT)]2, and by a topoisomerase I DNA unwinding (Topo I) assay. The dyes of this study showed tight binding to ctDNA with binding constants, K b, on the order of 106–107 M−1. The ITC and Topo I assay studies suggested that the 9-substituent has a strong impact on binding modes ranging from an apparent preference for intercalation with a 9-2-thienyl substituent (similar binding to [poly(dCdG)]2 and [poly(dAdT)]2, re-supercoiling of DNA in the Topo I assay at <10−5 M dye), to mixed binding modes with 9-phenyl derivatives (2- to 3-fold preference for binding to [poly(dAdT)]2, re-supercoiling of DNA in the Topo I assay at ∼2×10−5 M dye), to minor groove binding in a 9-(2-thienyl-5-diethylcarboxamide) derivative (strong preference for binding to [poly(dAdT)]2, did not show complete re-supercoiling in the Topo I assay). No binding to ctDNA was observed in one derivative with a 9-(3-thienyl-2-diethylcarboxamide) substituent, which cannot be co-planar with the xanthylium core. In series of dyes where the chalcogen atom was varied, the selenoxanthylium derivatives had 2- to 3-fold higher values of K b than the corresponding xanthylium, thioxanthylium, or telluroxanthylium derivatives, which all showed comparable values of K b. The chalcogen atom appeared to have little influence on binding mode. [Copyright &y& Elsevier]