3,231 research outputs found
Resistance of Alkali Activated Water-Cooled Slag Geopolymer to Sulphate Attack
Ground granulated blast furnace slag is a finely ground, rapidly chilled aluminosilicate melt material that is separated from molten iron in the blast furnace as a by-product. Rapid cooling results in an amorphous or a glassy phase known as GGBFS or water cooled slag (WCS). Alkaline activation of latent hydraulic WCS by sodium hydroxide and/or sodium silicate in different ratios was studied. Curing was performed under 100 % relative humidity and at a temperature of 38°C. The results showed that mixing of both sodium hydroxide and sodium silicate in ratio of 3:3 wt.,% is the optimum one giving better mechanical as well as microstructural characteristics as compared with cement mortar that has various cement content (cement : sand were 1:3 and 1:2). Durability of the water cooled slag in 5 % MgSO4 as revealed by better microstructure and high resistivity-clarifying that activation by 3:3 sodium hydroxide and sodium silicate, respectively is better than using 2 and 6 % of sodium hydroxide
n-Butyl 2-(2,4-dichloroanilino)-4,4-dimethyl-6-oxocyclohex-1-enecarbodithioate
The cyclohexene ring in the title compound, C19H23Cl2NOS2, adopts an envelope conformation, with the C atom bearing the two methyl groups representing the flap. This atom deviates by 0.630 (2) Å from the plane passing through the other five atoms of the ring (r.m.s. deviation = 0.020 Å). The molecular conformation is stabilized by an intramolecular N—H⋯S hydrogen bond
2-Hydroxyethyl 2-(2,4-dichloroanilino)-4,4-dimethyl-6-oxocyclohex-1-enecarbodithioate
The six-membered cyclohexene ring in the title compound, C17H19Cl2NOS2, adopts an envelope conformation, with the C atom bearing the two methyl groups representing the flap. This atom deviates by 0.716 (3) Å from the plane passing through the other five atoms of the ring (r.m.s. deviation = 0.072 Å). The molecular conformation is stabilized by an intramolecular N—H⋯S hydrogen bond. The hydroxy group engages in intermolecular O—H⋯O hydrogen bonding with adjacent acceptor atoms to generate a zigzag chain running along the c axis
n-Undecanyl 2-(4-chloroanilino)-4,4-dimethyl-6-oxocyclohex-1-enecarbodithioate
The six-membered cyclohexene ring in the title compound, C26H38ClNOS2, adopts an envelope conformation, with the C atom bearing the two methyl groups representing the flap. This atom deviates by 0.642 (4) Å from the plane passing through the other five atoms of the ring (r.m.s. deviation = 0.053 Å). The molecular conformation is stabilized by an intramolecular N—H⋯S hydrogen bond
n-Undecanyl 2-(4-bromoanilino)-4,4-dimethyl-6-oxocyclohex-1-enecarbodithioate
The six-membered cyclohexene ring in the title compound, C26H38BrNOS2, adopts an envelope conformation, with the C atom bearing the two methyl groups representing the flap. This atom deviates by 0.651 (3) Å from the plane passing through the other five atoms of the ring (r.m.s. deviation = 0.051 Å). The molecular conformation is stabilized by an N—H⋯S hydrogen bond. The title compound is isomorphous with n-undecanyl 2-(4-chloroanilino)-4,4-dimethyl-6-oxocyclohex-1-enecarbodithioate
n-Undecanyl 2-(2,4-dichloroanilino)-4,4-dimethyl-6-oxocyclohex-1-enecarbodithioate
The six-membered cyclohexene ring in the title compound, C26H37Cl2NOS2, adopts an envelope-shaped conformation, with the C atom bearing the two methyl groups representing the flap. This atom deviates by 0.658 (7) Å from the plane passing through the other five atoms of the ring (r.m.s. deviation = 0.005 Å). The molecular conformation is stabilized by an N—H⋯S hydrogen bond
Design, Synthesis, Chemical and Biochemical Insights Into Novel Hybrid Spirooxindole-Based p53-MDM2 Inhibitors With Potential Bcl2 Signaling Attenuation
The tumor resistance to p53 activators posed a clinical challenge. Combination studies disclosed that concomitant administration of Bcl2 inhibitors can sensitize the tumor cells and induce apoptosis. In this study, we utilized a rapid synthetic route to synthesize two novel hybrid spirooxindole-based p53-MDM2 inhibitors endowed with Bcl2 signaling attenuation. The adducts mimic the thematic features of the chemically stable potent spiro [3H-indole-3,2′-pyrrolidin]-2(1H)-ones p53-MDM2 inhibitors, while installing a pyrrole ring via a carbonyl spacer inspired by the natural marine or synthetic products that efficiently inhibit Bcl2 family functions. A chemical insight into the two synthesized spirooxindoles including single crystal x-ray diffraction analysis unambiguously confirmed their structures. The synthesized spirooxindoles 2a and 2b were preliminarily tested for cytotoxic activities against normal cells, MDA-MB 231, HepG-2, and Caco-2 via MTT assay. 2b was superior to 5-fluorouracil. Mechanistically, 2b induced apoptosis-dependent anticancer effect (43%) higher than that of 5-fluorouracil (34.95%) in three studied cancer cell lines, activated p53 (47%), downregulated the Bcl2 gene (1.25-fold), and upregulated p21 (2-fold) in the treated cancer cells. Docking simulations declared the possible binding modes of the synthesized compounds within MDM2
2,3,4,6-Tetra-O-acetyl-β-d-galactopyranosyl 2-(2,4-dichloroanilino)-4,4-dimethyl-6-oxocyclohex-1-enecarbodithioate
The cyclohexene ring in the title compound, C29H33Cl2NO10S2, adopts an envelope conformation, with the C atom bearing the two methyl groups representing the flap. This atom deviates by 0.63 (1) Å from the plane through the other five ring atoms (r.m.s. deviation = 0.11 Å). The molecular conformation is stabilized by an intramolecular N—H⋯S hydrogen bond. The crystal studied was a non-merohedral twin, with a minor twin component of 29%
Benzyl 2-(4-bromoanilino)-4,4-dimethyl-6-oxocyclohex-1-enecarbodithioate: first triclinic polymorph
The six-membered cyclohexene ring in the title compound, C22H22BrNOS2, adopts an envelope conformation, with the C atom bearing the two methyl groups representing the flap. This atom deviates by 0.686 (4) Å from the plane passing through the other five atoms of the ring (r.m.s. deviation = 0.025 Å). The molecular conformation is stabilized by an intramolecular N—H⋯S hydrogen bond
Measuring aortic pulse wave velocity using high-field cardiovascular magnetic resonance: comparison of techniques
<p>Abstract</p> <p>Background</p> <p>The assessment of arterial stiffness is increasingly used for evaluating patients with different cardiovascular diseases as the mechanical properties of major arteries are often altered. Aortic stiffness can be noninvasively estimated by measuring pulse wave velocity (PWV). Several methods have been proposed for measuring PWV using velocity-encoded cardiovascular magnetic resonance (CMR), including transit-time (TT), flow-area (QA), and cross-correlation (XC) methods. However, assessment and comparison of these techniques at high field strength has not yet been performed. In this work, the TT, QA, and XC techniques were clinically tested at 3 Tesla and compared to each other.</p> <p>Methods</p> <p>Fifty cardiovascular patients and six volunteers were scanned to acquire the necessary images. The six volunteer scans were performed twice to test inter-scan reproducibility. Patient images were analyzed using the TT, XC, and QA methods to determine PWV. Two observers analyzed the images to determine inter-observer and intra-observer variabilities. The PWV measurements by the three methods were compared to each other to test inter-method variability. To illustrate the importance of PWV using CMR, the degree of aortic stiffness was assessed using PWV and related to LV dysfunction in five patients with diastolic heart failure patients and five matched volunteers.</p> <p>Results</p> <p>The inter-observer and intra-observer variability results showed no bias between the different techniques. The TT and XC results were more reproducible than the QA; the mean (SD) inter-observer/intra-observer PWV differences were -0.12(1.3)/-0.04(0.4) for TT, 0.2(1.3)/0.09(0.9) for XC, and 0.6(1.6)/0.2(1.4) m/s for QA methods, respectively. The correlation coefficients (r) for the inter-observer/intra-observer comparisons were 0.94/0.99, 0.88/0.94, and 0.83/0.92 for the TT, XC, and QA methods, respectively. The inter-scan reproducibility results showed low variability between the repeated scans (mean (SD) PWV difference = -0.02(0.4) m/s and r = 0.96). The inter-method variability results showed strong correlation between the TT and XC measurements, but less correlation with QA: r = 0.95, 0.87, and 0.89, and mean (SD) PWV differences = -0.12(1.0), 0.8(1.7), and 0.65(1.6) m/s for TT-XC, TT-QA, and XC-QA, respectively. Finally, in the group of diastolic heart failure patient, PWV was significantly higher (6.3 ± 1.9 m/s) than in volunteers (3.5 ± 1.4 m/s), and the degree of LV diastolic dysfunction showed good correlation with aortic PWV.</p> <p>Conclusions</p> <p>In conclusion, while each of the studied methods has its own advantages and disadvantages, at high field strength, the TT and XC methods result in closer and more reproducible aortic PWV measurements, and the associated image processing requires less user interaction, than in the QA method. The choice of the analysis technique depends on the vessel segment geometry and available image quality.</p
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