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Salicylaldehyde-Promoted Cobalt-Catalyzed C-H/N-H Annulation associated with Indolyl Amides with Alkynes: Direct Combination of a 5-HT3 Receptor Villain Analogue.
Mucoadhesive polymers represent a major part of site-specific and localized retention strategies in oral drug delivery. The present research was designed to synthesize and characterize a novel mucoadhesive carbohydrate polymer (thiolated gum ghatti; TGG), which was employed to formulate mucoadhesive tablets of domperidone using an industrially viable compression coating technique. Thiolation of gum ghatti was achieved by the ester formation (esterification) between the hydroxyl group and the carboxyl group of gum ghatti and thioglycolic acid. TGG was characterized by various physicochemical techniques such as FTIR, XRD, SEM, and DSC. In rheological studies, the observed viscosities of pure gum mucin were 45.45 and 71.75 mPa·s and those of the thiolated gum were 78.7 and 112.58 mPa·s, respectively, in water and simulated gastric fluid. A significant increase in viscosity for thiolated gum may be attributed to increased macromolecular interactions responsible for enhanced mucoadhesive potential of thiolated gum. In silico studies corroborate the role of mucin gum interaction and energetic stabilization for enhanced mucoadhesion properties of thiolated gum. Ex vivo mucoadhesion strength of gum ghatti- and TGG-coated tablets was found to be ranging between 45.77 ± 1.49 and 88.16 ± 1.75 and 115.32 ± 2.36 and 184.65 ± 2.07 mN, respectively. In an acute oral toxicity study, TGG did not show any toxicity on the vital organs of the Wistar rat and proved to be a safe polymer. TGG may be regarded as a promising polymer for developing different mucoadhesive drug delivery systems.The isobutylene carbocation (CH3)2C=CH+ was obtained in amorphous and crystalline salts with the carborane anion CHB11Cl11 -. The cation was characterized by X-ray crystallography and IR spectroscopy. Its crystal structure shows a relatively uniform ionic interaction of the cation with the surrounding anions, with a slightly shortened distance between the C atom of the =CH group and the Cl atom of the anion, pointing to a higher positive charge on this group. In the amorphous phase, the asymmetric interaction of the cation with the anion increases, approaching ion pairing. This gives rise to a strong hyperconjugation between the two CH3 groups and the 2pz orbital of the central carbon sp2 atom (the red shift of the CH stretch is 150 cm-1); this effect stabilizes the cation. Over time, as the structure of the amorphous phase becomes more ordered, the hyperconjugation weakens and disappears in the crystalline phase with the disappearance of ion pairing. The carbocation stabilization in the crystalline phase is achieved due to the transfer of a portion of the charge to the neighboring anions, whereas the charge on the C=C bond becomes the strongest the C=C stretch frequency drops to ∼160 cm-1 relative to neutral isobutylene. The collected IR spectra for the optimized cation under vacuum (in the 6-311G ++ (d, p) basis for all HF, MP2, and DFT calculations) predict that a positive charge on the C=C bond increases its stretching frequency; this computational result contradicts the experimental data, perhaps because it does not take into account the significant impact of the environment.The present paper was aimed to investigate the physicochemical properties and combustion characteristics of corn straw briquette as a fuel energy. The results of physicochemical properties displayed that corn straw briquette has higher volatile matter, lower ash content, and higher heating value. Combustion characteristics and kinetic analysis were investigated using thermogravimetry analysis at various heating rates of 10, 15, and 20 °C/min. click here It was observed that the maximum burning rate shifted to a higher temperature as the heating rate increased. In addition, a lower heating rate would help in better heat transfer, leading to less mass residual. In contrast, the combustion characteristic index showed a nearly 2-fold increase under a higher heating rate, indicating a good combustion performance. The combustion kinetics were expressed using isoconversional methods with Kissinger-Akahira-Sunose and Ozawa-Flynn-Wall methods, which authenticated the average activation energy at 108.85 and 114.42 kJ/mol, respectively. These results can provide a theoretical basis and data support for further utilization of agriculture biomass briquette.Lab measurements for the rheological properties of mud are critical for monitoring the drilling fluid functions during the drilling operations. However, these measurements take a long time and might need more than one person to be completed. The main objectives of this research are to implement artificial intelligence for predicting the mud rheology from only Marsh funnel (μf) and measuring mud density (ρm) easily and quickly on the rig site. For the first time, an artificial neural network (ANN) was used to build different models for predicting the rheological properties of Max-bridge oil-based mud. The properties included the plastic viscosity (μp), yield point (γ), flow behavior index (η), and apparent viscosity (μa). Field measurements of 383 samples were used to build and optimize the ANN models. The obtained results showed that 32 neurons in the hidden layer and tan sigmoid function transfer function were the best parameters for all ANN models. The training and testing processes of models showed a strong prediction performance with a correlation coefficient (R) greater than 0.91 and an average absolute percentage error (AAPE) less than 5.31%. New empirical correlations were developed based on the optimized weights and biases of the ANN models. The developed empirical correlations were compared with the published correlations, and the comparison results confirmed that the ANN-developed correlations outperformed all previous work.Lovastatin is a standard therapy for dyslipidemia. Alternatively, some ethnomedicines, such as Coptidis preparation, have been used for the treatment of dyslipidemia. Statins and complementary and alternative medicines may possess individual mechanisms of action against dyslipidemia. We hypothesize that the combination of Coptidis preparation and lovastatin may have synergistic effects for the treatment of dyslipidemia. To investigate this hypothesis, we developed a validated ultra-high-performance liquid chromatography-tandem mass spectrometry method to monitor lovastatin and its metabolites for pharmacokinetic studies in rats. This study was divided into four groups lovastatin (10 mg/kg, p.o.) alone and lovastatin (10 mg/kg, p.o.) + Coptidis preparation (0.3, 1, or 3 g/kg, p.o.) for five consecutive days. In pharmacodynamic studies, a high-fat diet (HFD) was used to induce dyslipidemia in experimental rat models. The HFD rats were divided into four groups treatment with HFD, HFD + lovastatin (100 mg/kg, p.o.
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