The effects of LNR as a compatibilizer in binary blends of 60/40 NR/LLDPE have been investigated by means of differential scanning calorimetry, dynamic mechanical analysis and scanning electron microscopy. Special emphasis was given to the role of LNR in inducing interactions between NR and LLDPE. It has been observed that increasing LNR content decreases Tm and ΔHf which are indicators of the crystalline part of the blends. The decrease reflects a reduction in the degree of crystallinity which is due to the interference in the form of NR dissolution into the LLDPE phase. The phenomenon leads to a shift in Tg of the amorphous part of LLDPE to higher temperatures as observed by DMA thermograms. The dissolution effect creates better interactions between the phases leading to improvements in the compatibility of the blends. Further confirmation was obtained through SEM examination. 相似文献
Electron-beam (EB) irradiation technique has been used to improve the properties of 60/40 blends of NR/LLDPE in the presence of compatibilisers such as LNR-6 and LNR-16. Improvement in the physical properties of the blend correspond with the increase in the interactions created by EB irradiation as measured by gel content. For this blend ratio, the radiation dose of 200 kGy is found to be optimum. While LNR-6 shows some complimentary effects when it is used together with EB irradiation technique; LNR-16, however, causes an imperfection effect in the blend. The crosslinking process that takes place as a result of EB irradiation occurs at the expense of crystalline arrangement of the semi-crystalline LLDPE. For the morphological fixation purposes EB irradiation technique is found to be very effective. 相似文献
Protein kinases comprise one of the most important group of targets for drug discovery research today. Methods to identify novel kinase inhibitors by high-throughput screening have evolved rapidly in recent years. An important aspect is the availability of fluorescent probes that can be applied in a homogeneous, or mix-and-measure, assay format. Here, we illustrate the application of fluorescence read-out technologies for kinase targets in light of our own experiences in assay development and high-throughput screening. 相似文献
The anilic acids, 2,5-dihydroxy-1,4-benzoquinone (1a), 2,5-dibromo-3,6-dihydroxy-1,4-benzoquinone (bromanilic acid; 1b), 2,5-dichloro-3,6-dihydroxy-1,4-benzoquinone (chloranilic acid; 1c), and 2,5-dicyano-3,6-dihydroxy-1,4-benzoquinone (cyananilic acid; 1d), were cocrystallized with rigid organic ligands containing two pyridine rings, 2,4-bipyridine (2a), 4,4'-bipyridine (2b), 1,2-bis(2-pyridyl)ethylene (3a), 1,2-bis(4-pyridyl)ethylene (3b), 2,2'-dipyridylacetylene (4a), 3,3'-dipyridylacetylene (4b), and 4,4'-dipyridylacetylene (4c). Fourteen complexes 5-18 were obtained as single crystals, and their crystal structures were successfully determined by X-ray analysis. All complexes except those with 2a are 1:1 and are composed of an infinite linear or zigzag tape structure, the formation of which is ascribed to intermolecular O-H...N, N(+)-H...O, or N(+)-H...O(-) hydrogen bonds or a combination of these between the anilic acids and the dipyridyl compounds. In the complexes 5 and 6, no infinite tape structure is observed although the molecular units connected by a similar hydrogen-bonding pattern are formed. For the 1:1 complexes, we have found two types of stacking arrangements, segregated stacks (7, 9, 12-15, 18) and alternated ones (8, 10, 11, 16, 17). In the complexes of 1c with the series of dipyridylacetylenes 4 (14, 15, 17), the neutral, dication, and monocaction states are formed depending on the nitrogen positions, which can be attributed to the different basicity of the pyridyl groups. 相似文献
The crystalline photochromism of a diarylethene pyridyl ligand is applied to the modulation of the electronic environment of a high-spin Fe(II) metal ion. 相似文献
1-Benzyl-4-methylimidazoles with a range of substituents at the 2-position are prepared from O-pentafluorobenzoylamidoximes on treatment with catalytic amounts of Pd(PPh3)4 and triethylamine. The sequence provides access to optically active amino acid mimetics with a C-terminal imidazole. [structure: see text] 相似文献
A reversed-phase high-performance liquid chromatographic method was developed for the simultaneous determination of sofosbuvir and ledipasvir in tablet dosage form. The analysis was performed on Luna analytical column 250 × 4.6 mm, 5 µm, octyl silica packing (Si–[CH2]7–CH3) C8, using ammonium acetate buffer solution pH 7.0 and acetonitrile 35:65 % v/v as mobile phase at flow rate of 0.7 mL min−1 for isocratic elution. Detection of sofosbuvir and ledipasvir was performed on a UV detector at 245 nm. The retention times of sofosbuvir and ledipasvir were 4.468 ± 0.013 min and 8.242 ± 0.012 min, respectively, and the total run time was 20 min. The method was validated according to the requirements of the United States Pharmacopeia (category I). The overall recovery of both analytes was 100 ± 1 %; the relative standard deviation for precision and intraday precision was less than 2.0 %. The method was linear with correlation coefficient (r) >0.9999, limits of detection 0.485 and 0.175 µg mL−1, and limits of quantification was 1.619 and 0.586 µg mL−1 for sofosbuvir and ledipasvir, respectively. The method was successfully applied to the assay and in vitro dissolution studies of sofosbuvir and ledipasvir in tablet dosage form.
Chemistry of Natural Compounds - A new 9,19-cyclolanostane type arabinoside, 16,23;22,25-diepoxy-3β,22,23,24-tetrahydroxy-9,19-cyclolanostane-3-O-α-L-arabinopyranoside (1), together with... 相似文献
This paper obtains the conservation laws of the Klein–Gordon equation with power law and log law nonlinearities. The multiplier approach with Lie symmetry analysis is employed to obtain the conserved densities. The 1-soliton solutions are subsequently used to compute the conserved quantities from the conserved densities. Later the perturbation terms are added and the conservation laws of the perturbed Klein–Gordon equation are studied. 相似文献