Nanodiamond landmarks for subcellular multimodal optical and electron imaging.

There is a growing need for biolabels that can be used in both optical and electron microscopies, are non-cytotoxic, and do not photobleach. Such biolabels could enable targeted nanoscale imaging of sub-cellular structures, and help to establish correlations between conjugation-delivered biomolecules and function. Here we demonstrate a sub-cellular multi-modal imaging methodology that enables localization of inert particulate probes, consisting of nanodiamonds having fluorescent nitrogen-vacancy centers. These are functionalized to target specific structures, and are observable by both optical and electron microscopies. Nanodiamonds targeted to the nuclear pore complex are rapidly localized in electron-microscopy diffraction mode to enable "zooming-in" to regions of interest for detailed structural investigations. Optical microscopies reveal nanodiamonds for in-vitro tracking or uptake-confirmation. The approach is general, works down to the single nanodiamond level, and can leverage the unique capabilities of nanodiamonds, such as biocompatibility, sensitive magnetometry, and gene and drug delivery.

Langerhans cell histiocytosis associated with lichen sclerosus of the vulva: case report and review of the literature.

Langerhans cell histiocytosis (LCH) is characterized by a clonal proliferation of bone marrow-derived Langerhans cells. While cutaneous involvement is relatively common, LCH restricted to the vulvar area is a rare phenomenon and can occur in different clinical settings. Occasionally, vulvar LCH heralds subsequent multi-organ involvement with an aggressive clinical course. Even cases of LCH isolated to the vulvar area can present with local recurrences despite excision and radiation. We present a case of a 68-year-old female with a 1-month history of pruritic lesions on her vulva. Physical examination showed whitish plaques with scattered nodular areas on the labia majora. A vulvar biopsy showed a background of lichen sclerosus (LS) with foci of oval to polygonal cells with moderately abundant eosinophilic cytoplasm and folded nuclei showing frequent nuclear grooves. Immunohistochemical staining showed that the cells were positive for CD1a and S-100, confirming the diagnosis of LCH. On further workup, there was no evidence of disseminated disease involving other organs. While vulvar LCH is uncommonly seen, and with only one previous case report in the literature associated in the setting of lichen sclerosus, this case illustrates the importance of recognizing this condition and ensuring proper clinical follow-up to rule out a systemic involvement.

A combined experimental-computational investigation of carbon dioxide capture in a series of isoreticular zeolitic imidazolate frameworks.

A series of five zeolitic imidazolate frameworks (ZIFs) have been synthesized using zinc(II) acetate and five different 4,5-functionalized imidazole units, namely ZIF-25, -71, -93, -96, and -97. These 3-D porous frameworks have the same underlying topology (RHO) with Brunauer-Emmet-Teller surface areas ranging from 564 to 1110 m(2)/g. The only variation in structure arises from the functional groups that are directed into the pores of these materials, which include -CH(3), -OH, -Cl, -CN, -CHO, and -NH(2); therefore these 3-D frameworks are ideal for the study of the effect of functionality on CO(2) uptake. Experimental results show CO(2) uptake at approximately 800 Torr and 298 K ranging from 0.65 mmol g(-1) in ZIF-71 to 2.18 mmol g(-1) in ZIF-96. Molecular modeling calculations reproduce the pronounced dependence of the equilibrium adsorption on functionalization and suggest that polarizability and symmetry of the functionalization on the imidazolate are key factors leading to high CO(2) uptake.

Noninnocent dithiolene ligands: a new oxomolybdenum complex possessing a donor-acceptor dithiolene ligand.

A new monoanionic dithiolene ligand is found in Tp*MoO(S(2)BMOQO). A combination of X-ray crystallography, electronic absorption spectroscopy, resonance Raman spectroscopy, and bonding calculations reveal that the monoanionic dithiolene ligand possesses considerable thiolate-thione character resulting from an admixture of an intraligand charge transfer excited state into the ground state wave function. The unusual dithiolene exhibits a highly versatile donor-acceptor character that dramatically affects the Mo(IV/V) redox couple and points to a potentially noninnocent role of the pterin fragment in pyranopterin Mo enzymes.

DNA binding by Ru(II)-bis(bipyridine)-pteridinyl complexes.

The interactions of five bis(bipyridyl) Ru(II) complexes of pteridinyl-phenanthroline ligands with calf thymus DNA have been studied. The pteridinyl extensions were selected to provide hydrogen-bonding patterns complementary to the purine and pyrimidine bases of DNA and RNA. The study includes three new complexes [Ru(bpy)(2)(L-pterin)](2+), [Ru(bpy)(2)(L-amino)](2+), and [Ru(bpy)(2)(L-diamino)](2+) (bpy is 2,2'-bipyridine and L-pterin, L-amino, and L-diamino are phenanthroline fused to pterin, 4-aminopteridine, and 2,4-diaminopteridine), two previously reported complexes [Ru(bpy)(2)(L-allox)](2+) and [Ru(bpy)(2)(L-Me(2)allox)](2+) (L-allox and L-Me(2)allox are phenanthroline fused to alloxazine and 1,3-dimethyalloxazine), the well-known DNA intercalator [Ru(bpy)(2)(dppz)](2+) (dppz is dipyridophenazine), and the negative control [Ru(bpy)(3)](2+). Reported are the syntheses of the three new Ru-pteridinyl complexes and the results of calf thymus DNA binding experiments as probed by absorption and fluorescence spectroscopy, viscometry, and thermal denaturation titrations. All Ru-pteridine complexes bind to DNA via an intercalative mode of comparable strength. Two of these four complexes--[Ru(bpy)(2)(L-pterin)](2+) and [Ru(bpy)(2)(L-allox)](2+)--exhibit biphasic DNA melting curves interpreted as reflecting exceptionally stable surface binding. Three new complexes--[Ru(bpy)(2)(L-diamino)](2+), [Ru(bpy)(2)(L-amino)](2) and [Ru(bpy)(2)(L-pterin)](2+)--behave as DNA molecular "light switches."