A highly efficient and environmental-benign oxidation by dioxygen (or air) as the sole oxidant was first applied for the conversion of 2-imidazoline-5-carboxylic derivatives to imidazole-5-carboxylic derivatives in very good and excellent yields. The substituent effect on 2-imidazoline ring was investigated. This protocol was also suitable for the synthesis of 2-imidazoles in relatively large scale. 相似文献
A new preparative column for the vortex counter-current chromatograph was fabricated by making many (966) cylindrical separation units to a high-density polyethylene disk and then threading them with 6–40 taps. The resulting column had a total capacity of 364 mL. The performance of this vortex column was examined with three different two-phase solvent systems each using a set of suitable test samples: hexane–ethyl acetate–methanol–0.1 M hydrochloric acid (1:1:1:1, v/v) for the separation of DNP-amino acids; 1-butanol–acetic acid–water (4:1:5, v/v) for the separation of dipeptides; and hexane–acetonitrile–water (20:15:2, v/v) for the separation of Sudan dyes. Most of the separations show high partition efficiency of over a thousand theoretical plates, as expected based on the results previously obtained in preliminary separations with a small column. Overall, the results of the present study suggest that further improvement of the partition efficiency can be obtained by the modifying column configuration.
The title compounds 1-(4-aryl-5-triazolyl-2-thiazolyl)-3,5-diaryl-2-pyrazoline derivatives (3a–c) were synthesized by reacting 3,5-diaryl1-thiocarbamoyl -2-pyrazoline 1 with 2-bromo-1-aryl-2-(1H-1,2,4-triazol-1-yl) ethanones 2 in boiling ethanol. Their structures were characterized by IR, 1H-NMR, MS spectroscopic data and elementary analyses. The structure of compound (3a), C26H18Cl2N6S, was conclusively established with X-ray crystal structure analysis. It crystallizes in the Orthorhombic space group Pna2(1),
with a = 17.8160(5), b = 18.9125(7), c = 14.7926(4), α = 90°, β = 90°, γ = 90°and Dc = 1.379 mg/m3 for Z = 8, V = 4984.3(3) ?, μ(Mo–Kα) = 0.372 mm, λ = 0.71070 ?, the final R = 0.0527 and wR = 0.1307 for 43309 observed reflections with I > 2σ(I). The structure is stabilized by weak C–H···N intramolecular hydrogen bonds and C–H···Cg p-ring intermolecular interactions
and gives support to molecular packing stability in the unit cell. 相似文献
In the postgenome era, biology and medicine are rapidly evolving towards quantitative and systems studies of complex biological systems. Emerging breakthroughs in microfluidic technologies and innovative applications are transforming systems biology by offering new capabilities to address the challenges in many areas, such as single-cell genomics, gene regulation networks, and pathology. In this review, we focus on recent progress in microfluidic technology from the perspective of its applications to promoting quantitative and systems biomolecular analysis in biology and medicine. 相似文献
In Western blotting, a suitable loading control is indispensable for correcting errors in the total amount of loaded protein. Immunodetection of housekeeping proteins and total protein staining have traditionally been used as loading control methods. Direct Blue 71 (DB71) staining—a novel, sensitive, dye‐binding staining method compatible with immunodetection—may offer advantages over these traditional loading control methods. Three common neuroscientific samples (human plasma, human oligodendrocytes, and rat brain) were employed to assess DB71 staining as a loading control method for Western blotting. DB71, CBB, one traditional housekeeping protein, and one protein of interest were comparatively assessed for reliability and repeatability and linear dynamic range over 2.5–40 μg of protein loaded. DB71's effect on the reliability and repeatability and linear dynamic range of immunoreaction were also assessed. Across all three sample types, DB71 was either equivalent or superior to CBB and housekeeping protein‐based methods in terms of reliability and repeatability and linear dynamic range. Across all three sample types, DB71 staining did not impair the reliability and repeatability or linear dynamic range of immunoreaction. Our results demonstrate that the DB71 staining can be used as a destaining‐free alternative loading control method for Western blotting. 相似文献
Thermotropic ionic liquid crystals (LCs) are useful for a number of applications such as anisotropic ion transport and as organised reaction media/solvents because of their ordered fluid properties and intrinsic charge units. A large number of different ionic LC architectures are known, but only a handful of examples of gemini (i.e. paired or dimeric) ionic LCs have been prepared and studied. In this work, a series of 20 new symmetric, imidazolium-based, gemini cationic LCs containing two bridged imidazolium cations and two pendant alkyl chains was synthesised, and the thermotropic LC behaviours were characterised. The imidazolium unit provides a highly tunable and modular platform for the design and synthesis of gemini cationic LCs which offers excellent structure control. As expected, the thermotropic LC properties of these new amphilphilic, gemini ionic LCs were found to be strongly influenced by the length of the spacer between the imidazolium units, the length of the pendant alkyl tails, and the nature of the anion. Smectic A (SmA) thermotropic LC phases were observed in more than half of the gemini imidazolium LC systems studied. 相似文献