2,2-Difluoro-4-phenyl-1,3,2-dioxaborolo[4,5-c]chromen-5-ium-2-ide

In the crystal, the inversely oriented mol­ecules of the title compound, C15H9BF2O3, form stacks along the a axis via π–π inter­actions between parallel phenyl­chromenium fragments. Linked by a network of C—H⋯F inter­actions, the stacks form layers in the ac plane that are dispersively stabilized in the crystal structure. Two F atoms bonded to the B atom are located in the plane perpendicular to the planar skeleton of the mol­ecule made rigid by two intra­molecular C—H⋯O inter­actions

Commerce of Massachusetts with the West Indies before the American Revolution ..

Typewritten sheets in cover. Thesis (M.A.)--Boston University Bibliography: p. 94-100

2-(4-Fluoro­phen­yl)-3-hy­droxy-4H-chromen-4-one

In the crystal structure of the title compound, C15H9FO3, inversely oriented mol­ecules form inversion dimers through pairs of O—H⋯O hydrogen bonds. The benzene ring is twisted at an angle of 12.0 (1)° relative to the 4H-chromene skeleton of the mol­ecule. Adjacent 4H-chromene units are parallel in a given column or oriented at an angle of 50.0 (1)° in neighboring, inversely oriented, columns, forming a herringbone pattern

Flow Cytometric Detection of the Classical Hodgkin Lymphoma: Clinical and Research Applications

Classical Hodgkin lymphoma (CHL) is a relatively uncommon B cell-derived neoplasm that presents with rare malignant cells in an abundant reactive background. The diagnosis of CHL currently relies on a combination of morphologic findings and immunohistochemical stains. With the exception of rare cases with dramatically increased malignant populations, isolation of pure viable tumor cells has not been historically possible. Recently, a reliable flow cytometric assay for direct detection and isolation of the malignant cells in this disease has been developed. This assay has proven useful diagnostically and has been clinically validated to have a very high sensitivity and nearly absolute specificity for the diagnosis of CHL in routine clinical samples. This paper describes the methodology for the flow cytometric detection of CHL in clinical samples as well as current state of evaluation of background lymphocytes as an adjunct diagnostic test. Also discussed are exciting research applications of the direct isolation of viable tumor cells in CHL. The current state of flow cytometric evaluation of nodular lymphocyte predominant Hodgkin lymphoma and T cell-rich large B cell lymphoma is also briefly discussed

Investigations of Bis-chromophore Systems: Relationship between Spectral Behaviour and Charge Transfer in 2-(3-coumaroyl)-benzopyrylium Perchlorates

The dependence of spectral properties and interfragmental charge transfer (ICT) on excitation, relaxation and excited state deactivation of 2-(3-cou­maroyl)-benzopyry­lium perchlorates has been analyzed. It was found that the positions of emission bands and rate constants of radiationless deactivation linearly correlate with ICT upon excited state deactivation, and Stokes’ shifts of fluorescence demonstrate linear dependence on ICT upon structural relaxation in the excited state

Spectral and Basic Properties of Flavones in the Ground and Excited States

Dependence between structures of R-oxyflavones and their spectral and basic properties has been investigated. It was found that pKa of flavones, depending on positions of hydroxy and methoxy groups, increase by 6-8 orders of magnitude upon excitation and reaches 3.7-6.6 units. Due to high pKa* value carbonyl group can serve as a proton acceptor in the excited-state intramolecular proton transfer as far as in the formation of phototautomers of 7- and 4'-hydroxyflavones in protic solvents

3-Hy­droxy-2-(4-meth­oxy­phen­yl)-4H-chromen-4-one

In the title compound, C16H12O4, the benzene ring is twisted at an angle of 12.3 (1)° relative to the 4H-chromene skeleton, and an intramolecular O—H⋯O hydrogen bond occurs. The meth­oxy group is almost coplanar with the benzene ring [1.5 (1)°]. In the crystal, inversely oriented mol­ecules are arranged in double (A, A′) columns, along the b axis, and are linked by a network of inter­molecular O—H⋯O hydrogen bonds (between A and A′) and C—H⋯π contacts (within A or A′). The 4H-chromene cores are parallel within A or A′, but make a dihedral angle of 88.6 (1)° between A and A′