Preparation and properties of antitubercular 1‐piperidino‐3‐arylthioureas

1‐Piperidino‐3‐arylthioureas, of interest in the investigation of novel heterocyclic structures for their anti‐tubercular activity, may be conveniently prepared in good yield and purity by the reaction of 1‐arninopiperi‐dine with aryl isothiocyanates in ethanol. The reaction takes place readily without the complication of thiourethane contaminants, and the products may be suitably identified by significant characteristics in the infrared spectra and the hydrogen and carbon magnetic resonance spectra.     

Three dimensional microvascular measurements in human endometrium using optical slices from laser scanning confocal microscopy (LSCM)

There is increasing interest in the structure of the microvascular environment in human endometrium because of the recognition of the complexity and functional importance of this tissue. Endometrial microcirculatory networks and their relationships have rarely been studied in three-dimensions.Longitudinal uterine slices containing endometrial tissue were carefully selected from women undergoing a hysterectomy. Formalin-fixed endometrial sections (≤50 μm) representing the fundal and isthmic regions were immunofluorescently labeled with monoclonal antibody (CD34) to target the endothelium of microvessel and fluorescein isothiocyanate (FITC) labeled goat anti-mouse. Digital images were acquired using a Nikon Eclipse E800 microscope equipped with a Radiance 2000 confocal scanning laser attachment. ImarisBasic 4.1 visualization suite was utilized for qualitative interpretation. NeuronTracer 1.0 software was utilized to derive the length and numerical densities.There were significant changes across the phases of the menstrual cycle in functional and basal endometrial layers in vessel length density (LD_v) and branch point density (ND_v) within both fundal and isthmic regions of the uterus (P < 0.001). There was also a significant effect of menstrual cycle phase on mean vessel segment length (SL_v) within each region and within each of the layers (P < 0.001). The capillary radial diffusion distance r(diff) was negatively correlated with LD_v. In general, within each of the menstrual cycle phases, LD_v, ND_v were greater in the fundal than the isthmic regions while, in contrast, SL_v was found to be greatest in the isthmic region.Utilization of immunofluorescence and laser scanning confocal microscopy has enabled us to demonstrate significant vascular changes in human endometrial layers illustrating that in general, within each of the menstrual cycle phases, vessel length and branch point densities were greater in the fundal than the isthmic regions, while vessel segment lengths were found to be greatest in the isthmic region.     

Direct top–down fabrication of nanoscale electrodes for organic semiconductors using fluoropolymer resists

We report the use of a fluoropolymer resist for the damage-free e-beam lithographic patterning of organic semiconductors. The same material is also shown to be suitable as an orthogonal electron beam resist for the patterning of top-contact electrodes on organic thin films. We demonstrate this by characterizing pentacene field-effect transistors with feature sizes as small as 100 nm and compare the performance of bottom- and top-contacted devices.     

The feasibility of assessing branched-chain amino acid metabolism in cellular models of prostate cancer with hyperpolarized [1-C]-ketoisocaproate

Recent advancements in the field of hyperpolarized ¹³C magnetic resonance spectroscopy (MRS) have yielded powerful techniques capable of real-time analysis of metabolic pathways. These non-invasive methods have increasingly shown application in impacting disease diagnosis and have further been employed in mechanistic studies of disease onset and progression. Our goals were to investigate branched-chain aminotransferase (BCAT) activity in prostate cancer with a novel molecular probe, hyperpolarized [1-¹³C]-2-ketoisocaproate ([1-¹³C]-KIC), and explore the potential of branched-chain amino acid (BCAA) metabolism to serve as a biomarker. Using traditional spectrophotometric assays, BCAT enzymatic activities were determined in vitro for various sources of prostate cancer (human, transgenic adenocarcinoma of the mouse prostate (TRAMP) mouse and human cell lines). These preliminary studies indicated that low levels of BCAT activity were present in all models of prostate cancer but enzymatic levels are altered significantly in prostate cancer relative to healthy tissue. The MR spectroscopic studies were conducted with two cellular models (PC-3 and DU-145) that exhibited levels of BCAA metabolism comparable to the human disease state. Hyperpolarized [1-¹³C]-KIC was administered to prostate cancer cell lines, and the conversion of [1-¹³C]-KIC to the metabolic product, [1-¹³C]-leucine ([1-¹³C]-Leu), could be monitored via hyperpolarized ¹³C MRS.     

35Cl NQR spectra of group 1 and silver dichloromethanesulfonates

The dichloromethanesulfonates of silver and other +1-charged cations, M ^?+?(Cl₂CHSO $_{3}^{-})$ (M = Ag, Tl, Li, Na, K, Rb, Cs) were synthesized and studied by ³⁵Cl NQR. Dichloromethanesulfonic acid was prepared by the methanolysis of dichloromethanesulfonyl chloride, and was then neutralized with the carbonates of the +1-charged cations to produce the corresponding dichloromethanesulfonate salt. This NQR study completed the investigation of the chloroacetates and chloromethanesulfonates of silver, Ag^?+?(Cl _x CH_3???x SO $_{3}^{-})$ and Ag^?+?(Cl _x CH_3???x CO $_{2}^{-})$ , and suggests (1) that the ability of organochlorine atoms to coordinate to silver decreases as the number of electron-withdrawing groups (Cl, SO $_{3}^{-}$ , CO $_{2}^{-})$ attached to the carbon atom increases; (2) that the unusually large NQR spectral width found among M ^?+?(Cl₂CHCO $_{2}^{-})$ salts is not present among M ^?+?(Cl₂CHSO $_{3}^{-})$ salts, and therefore is not generally characteristic of the dichloromethyl group in salts.     

Heuristics for similarity searching of chemical graphs using a maximum common edge subgraph algorithm

Recently a method (RASCAL) for determining graph similarity using a maximum common edge subgraph algorithm has been proposed which has proven to be very efficient when used to calculate the relative similarity of chemical structures represented as graphs. This paper describes heuristics which simplify a RASCAL similarity calculation by taking advantage of certain properties specific to chemical graph representations of molecular structure. These heuristics are shown experimentally to increase the efficiency of the algorithm, especially at more distant values of chemical graph similarity.     

Groups Quasi-Isometric to H2xR

The most powerful geometric tools are those of differentialgeometry, but to apply such techniques to finitely generatedgroups seems hopeless at first glance since the natural metricon a finitely generated group is discrete. However Gromov recognizedthat a group can metrically resemble a manifold in such a waythat geometric results about that manifold carry over to thegroup [18, 20]. This resemblance is formalized in the conceptof a ‘quasi-isometry’. This paper contributes toan ongoing program to understand which groups are quasi-isometricto which simply connected, homogeneous, Riemannian manifolds[15, 18, 20] by proving that any group quasi-isometric to H²xRis a finite extension of a cocompact lattice in Isom(H²xR) orIsom((2, R)).     

Functional optical coherence tomography for detecting neural activity through scattering changes

We have demonstrated functional optical coherence tomography (fOCT) for neural imaging by detecting scattering changes during the propagation of action potentials through neural tissue. OCT images of nerve fibers from the abdominal ganglion of the sea slug Aplysia californica were taken before, during, and after electrical stimulation. Images acquired during stimulation showed localized reversible increases in scattering compared with those acquired before stimulation. Motion-mode OCT images of nerve fibers showed transient scattering changes from spontaneous action potentials. These results demonstrate that OCT is sensitive to the optical changes in electrically active nerve fibers.