Appendiceal neoplasms are uncommon tumors of the gastrointestinal tract that may manifest with symptoms of appendicitis, right lower quadrant pain, or palpable mass, leading to imaging or surgical intervention. The majority of appendiceal masses consist of primary epithelial neoplasms and neuroendocrine tumors (NETs). Epithelial neoplasms-mucinous and nonmucinous types-are more often detected at imaging than NETs due to their larger size and propensity for peritoneal spread and metastatic disease. Epithelial mucinous neoplasms are defined by the presence of mucin, detected at radiologic and pathologic examination. A mucocele or pseudomyxoma peritonei from epithelial mucinous tumors are the two most common cross-sectional imaging findings of appendiceal mucinous neoplasms. Nonmucinous epithelial tumors are less common and manifest as masses similar to colonic-type malignancies. NETs are often discovered incidentally at appendectomy due to their small size and nonaggressive behavior. Imaging findings of primary appendiceal tumors may overlap with those of acute appendicitis. Additionally, an appendiceal mass may cause acute appendicitis, obscuring the underlying mass. Other neoplasms including lymphoma, sarcoma, mesenchymal and nerve sheath tumors, or secondary malignant involvement of the appendix are rare. Treatment depends on the histologic subtype and extent of disease. Detailed description of organ, nodal, and peritoneal involvement informs surgical management with the goal of complete cytoreduction. Novel treatments such as hyperthermic intraperitoneal chemotherapy have increased survival for patients with mucinous tumors. RSNA, 2017.
4‘-(Ferrocenyl)-2,2‘:6‘,2‘ ‘-terpyridine (Fctpy) and 4‘-(4-pyridyl)-2,2‘:6‘,2‘ ‘-terpyridine (pytpy) were prepared from
the corresponding ferrocene- and pyridinecarboxaldehyle and 2-acetylpyridine using the Krohnke synthetic
methodology. Metal complexes, [M(Fctpy)2](PF6)2 (M = Ru, Fe, Zn), [Ru(tpy)(Fctpy)](PF6)2 (tpy = 2,2‘:6‘,6‘ ‘-terpyridine), and [Ru(pytpy)2](PF6)2 were prepared and characterized. Cyclic voltammetric analysis indicated RuIII/II
and ferrocenium/ferrocene redox couples near expected potentials (RuIII/II ∼1.3 V and ferrocenium/ferrocene ∼0.6
V vs Ag/AgCl). In addition to dominant πtpy → πtpy* UV absorptions near 240 and 280 nm and dπ
Ru → πtpy*
MLCT absorptions around 480 nm, the complexes [Ru(Fctpy)2](PF6)2 and [Ru(tpy)(Fctpy)](PF6)2 exhibit an unusual
absorption band around 530 nm. Resonance Raman measurements indicate that this band is due to a 1[(d(π)Fc)6]
→ 1[(d(π)Fc)5(π*tpy
Ru)1] transition. For [Ru(Fctpy)2](PF6)2 and [Ru(tpy)(Fctpy)](PF6)2, excited-state emission and
lifetime measurements indicated an upper-limit emission quantum yield of 0.003 and an upper-limit emission
lifetime of 0.025 μs. The influence of the ferrocenyl site on excited-state decay is discussed, and an excited-state
energy level diagram is proposed.
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