No abstract

Cobalt complexes that undergo charge-transfer induced spin-transitions (CTIST) or valence tautomerism (VT) from low spin (LS) Co(III) to high spin (HS) Co(II) are potential candidates for magneto-optical switches. We use M-edge XANES spectroscopy with 40 fs time resolution to measure the excited-state dynamics of Co(III)(Cat-N-SQ)(Cat-N-BQ), where Cat-N-BQ and Cat-N-SQ are the singly and doubly reduced forms of the 2-(2-hydroxy-3,5-di-tert-butylphenyl-imino)-4,6-di-tert-butylcyclohexa-3,5-dienone ligand. The extreme ultraviolet probe pulses, produced using a tabletop high-harmonic generation light source, measure 3p3d transitions and are sensitive to the spin and oxidation state of the Co center. Photoexcitation at 525 nm produces a low-spin Co(II) ligand-to-metal charge transfer state which undergoes intersystem crossing to high-spin Co(II) in 67 fs. Vibrational cooling from this hot HS Co(II) state competes on the hundreds-of-fs timescale with back-intersystem crossing to the ground state, with 60% of the population trapped in a cold HS Co(II) state for 24 ps. Ligand field multiplet simulations accurately reproduce the ground-state spectra and support the excited-state assignments. This work demonstrates the ability of M-edge XANES to measure ultrafast photophysics of molecular Co complexes.<br><br><br>

There are multiple variants of normal anatomy involving multiple organ systems, many of which are well documented throughout the medical community. Specifically, the pancreas can demonstrate a wide range of variants that include divisum, ectopic tissue, annular pancreas, ductal variation, and pancreatic rests. However, upon literature review, a complete duplication of the pancreas resulting in two separate pancreases is rarely documented. This case provides an interesting diagnosis of two individual pancreases in a patient whom initially presented clinically with recurrent bouts of acute pancreatitis and weight loss status post prior cholecystectomy. Dedicated CT, MRI, MRCP, and endoscopic ultrasound were able to delineate pertinent anatomy and acute findings. The resultant patient course is difficult to predict secondary to limited documentation of duplicated pancreases in the medical literature. Additionally, the case helps provide insight into complications that may arise from this embryologic anomaly, the best imaging techniques for evaluation, and future management of this patient. Keywords: Duplicated pancreas; Anomaly; Variant; Pancreatitis CaseThroughout the history of medicine, and specifically radiology, there is documentation of extensive anatomical variations involving multiple organ systems, which range from person to person. In regard to the pancreas, there are numerous descriptions of variant anatomy that include divisum, ectopic tissue, annular pancreas, ductal variations, and pancreatic rests [1][2][3]. These anatomical variants are largely related to embryologic development and associated congenital anomalies [3,4]. Additionally, certain malformations such as a circumportal pancreas can result in vascular manifestations including encasement of the portal vein or superior mesenteric vein [5]. Postsurgical, post-traumatic, and post-inflammatory conditions are additional etiologies that can result in varying anatomy of the pancreas [6,7]. Many of these anomalies have been described, though current literature briefly expands upon a complete duplication of the pancreatic system, resulting in two fully developed, adjacent pancreases.This case presents a 26 year old female initially presented with upper abdominal pain during her first pregnancy and was diagnosed with acute pancreatitis by laboratory evaluation. Two months following delivery of this first pregnancy, the patient again presented with upper abdominal pain and was again diagnosed with acute pancreatitis by laboratory evaluation. Lipases at these times were greater than 10,000 U/L on one occasion and 2,117 U/L on another. It wasn't until two years later that the patient presented with her third episode of acute pancreatitis that imaging was performed.The initial imaging evaluation during this third acute episode was by CT and then subsequent MRI/MRCP. The studies demonstrated two separate pancreases, as well as edema within and adjacent to the more anterior pancreas, consistent with acute pancreatitis. The second, more anterior panc...