Improved thromboresistance and analytical performance of intravascular amperometric glucose sensors using optimized nitric oxide release coatings

In this work, nitric oxide (NO) release coatings designed for intravenous amperometric glucose sensors are optimized through the use of a polylactic acid (PLA) layer doped with a lipophilic diazeniumdiolated species that releases NO through a proton-driven mechanism. An Elast-Eon E2As polyurethane coating is used to both moderate NO release from the sensor surface and increase the sensor''s linear detection range toward glucose. These sensors were evaluated for thromboresistance and in vivo glucose performance through implantation in rabbit veins. By maintaining NO flux on a similar scale to endogenous endothelial cells, implanted glucose sensors exhibited reduced surface clot formation which enables more accurate quantitative glucose measurements continuously. An in vivo time trace of implanted venous sensors demonstrated glucose values that correlated well with the discrete measurements of blood samples on a benchtop point-of-care sensor-based instrument. The raw measured currents from the implanted glucose sensors over 7 h time periods were converted to glucose concentration through use of both a one-point in vivo calibration and a calibration curve obtained in vitro within a bovine serum solution. Control sensors, assembled without NO release functionality, exhibit distinctive surface clotting over the 7 h in vivo implantation period.     

β-Octafluorinated tetrakis(ethoxycarbonyl)porphyrin

Tetrakis(alloxycarbonyl)porphyrin and its β-octafluoro-substituted derivatives were synthesized via Lindsey method and transformed to their zinc complexes.Single crystal X-ray structures of corresponding Zn(Ⅱ) porphyrins revealed that β-octafluorination will give more compactness of porphyrin moieties in the crystal structure owing to the hydrogen bonding interactions involving β-fluorine atoms.An unusual six-coordinated Zn(Ⅱ) was found via intramolecular coordination of oxygen atom of meso-substituents with central Zn(Ⅱ).     

Divergent pathways of β,γ-unsaturated α-diazocarbonyl compounds catalyzed by dirhodium and Lewis acids catalysts separately or in combination

β,γ-Unsaturated a-diazocarbonyl compounds possess two reactive sites for electrophilic addition-one at the diazo carbon and the other at the vinylogous γ-position.Controlled by catalyst,divergent transformations are achieved starting from the same starting materials,either by Lewis acid-catalyzed addition or by dirhodium-catalyzed metal carbene reactions.In select cases two catalysts working in combination or in sequence provide a relay for cascade transformations.In this review,we summarize advances in catalyst-dependent divergent transformations of β,γ-unsaturated α-diazocarbonyl compounds and highlight the potential of this exciting research area and the many challenges that remain.     

A facile approach to tricyclo[6.4.0.04,9]-dodecane framework

The unusual tricyclo[6.4.0.0^4.9]dodecane framework was constructed in eight linear steps in 13%overall yield.An innovative strategy accessing the framework from bicyclo[3.3.1]nonanes was employed.The key steps involve a Robinson annulation,a base induced decarboxylation and epimerization in a single step,and an intramolecular alkylation.     

Folate binding protein—Outlook for drug delivery applications

Serum proteins represent an important class of drug and imaging agent delivery vectors. In this minireview, key advantages of using serum proteins are discussed, followed by the particular advantages and challenges associated with employing soluble folate binding protein. In particular, approaches employing drugs that target folate metabolism are reviewed. Additionally, the slow-onset, tightbinding interaction of folate with folate binding protein and the relationship to a natural oligomerization mechanism is discussed. These unique aspects of folate binding protein suggest interesting applications for the protein as a vector for further drug and imaging agent development.     

Effi cient synthesis of fused pyrazoles via simple cyclization of o-alkynylchalcones with hydrazine

The synthesis of pyrazole derivatives from o-alkynylchalcones and hydrazine via simple cyclization is described. This greener syntheticmethodology provides a straightforward approach to the synthesis of a variety of pyrazole derivatives under mild reaction condition.     

A facile and convenient synthesis of novel imidazo[1,2-b] isoxazoles and their Mannich bases as potential biodynamic agents

A series of novel imidazo[1,2-b]isoxazoles 3 and their Mannich bases 4–6 were synthesized via convenient reactions. The reaction of 3-aminoisoxazole 1 with substituted phenacyl bromides 2 in dry ethanol afforded the corresponding 6-methyl-3-aryl imidazo[1,2-b]isoxazoles 3 in good yields.Compounds 3 on treatment with 37% formaline and secondary amines furnished the corresponding novel Mannich bases viz., 6-methyl-3-aryl-2-(morpholine/pyrrolidin-1-yl/piperidin-1-yl)-methyl-imidazo[1,2-b]isoxazoles 4–6.     

Synergetic influence of ex-situ camphoric carbon nano-grafting on lithium titanates for lithium ion capacitors

The present study provides detailed experimental results on the synthesis and characterization of carbonized lithium titanate spinel(LTO) composites as electrode materials for lithium ion capacitor.The LTO particles were grafted with a porous carbon layer obtained from the pyrolysis of camphor.The graphitic nature of the carbon was confirmed through Raman spectroscopy.The relative contributions from the capacitive and diffusion controlled processes underlying these electrodes were mathematically modeled.Electron transport mechanism underlying these electrodes was determined by measuring the work functions(φ) of LTO and carbon grafted LTO using ultraviolet photoelectron spectroscopy.These carbon grafted LTO composites exhibited an energy density of 330 m Wh L-1and a peak power density of 2.8 k W L-1,when employed as electrodes in coin cells with excellent cycling stability at the end of 4000 cycles.     

Sensing behavior of BN nanosheet toward nitrous oxide: A DFT study

In order to develop a sensor for the detection of toxic N₂O molecules, the interaction of pristine and Aldoped BN nanosheets with an N₂O molecule was investigated using density functional theory calculations. It was found that unlike the pristine sheet, the Al-doped sheet can effectively interact with the N₂O molecule so that its electronic properties and conductivity are dramatically changed. Webelieve that replacing a B atom of the BN sheet with an Al atom may be a good strategy for improving the sensitivity of these nanosheets toward N₂O, which cannot be trapped and detected by the pristine sheet.     

[12] ane N_3-based BODIPY as a selective and sensitive off–on sensor for the sequential recognition of Cu~(2+) ions and ADP

A novel [12]aneN3-based BODIPY sensor 1 can be applied in the sequential recognition of Cu2 and ADP in aqueous solution and living cells with high selectivity and sensitivity