This is a study for the comparison of existing test methods for measuring the density of natural fibres to be used as reinforcement in biocomposite materials. Normally, any such method is evaluated by referring to its accuracy, cost, speed of test result (i.e. how quick a method is to give the result), and whether it is convenient and safe to use. Through literature review, we identified five such methods: (1) diameter and linear density, (2) Archimedes, (3) helium pycnometry, (4) gradient column and (5) liquid pycnometry. The same sample (oilseed flax fibres) was tried using these methods to measure its density. As a result of the study, two methods are recommended: Archimedes (with the use of canola oil as immersion fluid) and the helium pycnometry. The former was found to be simple, quick to give the result and incur lower cost, and therefore promising for general use in measuring the density of natural fibre, but the latter, although capable of providing more repeatable results, be at a much higher cost.

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Background: Reaction of α,β-unsaturated ketones with o-phenylenediamine afforded corresponding 2,3-dihydro-1H-1,5- benzodiazepines. Objective: α,β-Unsaturated ketones of 6-acetyl-5-hydroxy-4-methylcoumarin were precursors for synthesis of 2,3-dihydro1H-1,5-benzodiazepines through its reaction with o-phenylenediamine. Method: Enones of 6-acetyl-5-hydroxy-4-methylcoumarin were prepared from this ketone and (un)substituted benzaldehydes in the presence of piperidine, triethylamine, or pyridine as a catalyst in absolute ethanol with 1:1 molar ratios, respectively. 2ʹ,3ʹ-Dihydro-1H-1ʹ,5ʹ-benzodiazepines were synthesized by using the reaction of these enones with o-phenylenediamine in absolute ethanol in the presence of with glacial acetic acid as a catalyst. Their biological activities were evaluated using disk diffusion method. Method: Enones of 6-acetyl-5-hydroxy-4-methylcoumarin were prepared from this ketone and (un)substituted benzaldehydes in the presence of piperidine, triethylamine, or pyridine as a catalyst in absolute ethanol with 1:1 molar ratios, respectively. 2ʹ,3ʹ-Dihydro-1H-1ʹ,5ʹ-benzodiazepines were synthesized by using the reaction of these enones with o-phenylenediamine in absolute ethanol in the presence of with glacial acetic acid as a catalyst. Their biological activities were evaluated using disk diffusion method. Results: Seven new 2ʹ,3ʹ-dihydro-1H-1ʹ,5ʹ-benzodiazepines were obtained and their structures were confirmed by thin layer chromatography, IR, NMR and MS spectra. Some synthesized benzodiazepines had antibacterial and antifungal activities againsts Escherichia coli (Gram-(−) bacterium), Staphylococus epidermidis (Gram-(+) bacterium). Candida albicans (fungus). Conclusion: The formation of enones from 6-acetyl-5-hydroxy-4-methylcoumarin and (un)substituted benzaldehydes could be catalyzed by piperidine, triethylamine, pyridine to afford the similar yields. The formation of 2ʹ,3ʹ-dihydro-1H-1ʹ,5ʹbenzodiazepine structure from the aforementioned enones and o-phenylenediamine.

Some α,β-unsaturated ketones 4a–g of 3-acetyl-4-hydroxyquinolin-2(1H)-one were prepared and converted into a series of new hybrid compounds, quinoline-benzothiazepine 6a–g. Compounds 6d and 6g had the best activity against HepG2 and KB cell lines.

While much research focuses on social media and urban movements, almost no research explores its potentially divergent effects in rural areas. Building on recent work emphasizing the multidimensional effects of online communication on vertical and horizontal information, we argue that while the Internet may facilitate large-scale urban movements, it inhibits large-scale rural movements. Because social media increases vertical information flows between government and citizens, the central government responds quickly to rural protests, preventing such protests from developing into a large-scale movement. By contrast, social media does less to change the vertical information flows in urban areas. We explore the plausibility of our argument by process tracing the evolution of protests in urban and rural areas in Vietnam in the pre-Internet and in the Internet eras.

Coumarin-pyrimidine hybrid compounds were synthesized by condensation reaction of α,β-unsaturated ketones of 6-acetyl-5-hydroxy-4-methylcoumarin with guanidine. The reaction yields were of 42–62%. The antidiabetic and anticancer activities of these compounds were examined. These compounds displayed low toxicity to two cancer cell lines (including KB and HepG2 ones), but exhibited remarkably active against α-amylase with IC 50 values of 102.32 ± 1.15 μM to 249.52 ± 1.14 μM and against α-glucosidase with IC 50 values of 52.16 ± 1.12 μM to 184.52 ± 1.15 μM. Amongst these compounds, 6c was the best inhibitory activity against α-amylase, and 6f had the highest activity against α-glucosidase. The kinetics of inhibitor 6f was competitive α -glucosidase inhibitor property. ADMET predictions showed that almost all synthesized compounds exhibited drug-like activity. IFD and MD simulations were carried out on enzymes 4W93 and 5NN8 to elucidate inhibitory potential of 6c and 6f against tested enzymes. The binding free energy calculation by MM-GBSA approach showed that Coulomb, lipophilic and van der Waals energy terms are major contributors for the inhibitor binding. Molecular dynamics simulations in water solvent system were carried out for the 6f /5NN8 complex to elucidate the variability of active interactions between ligand 6f and active pockets of this enzyme. Graphical Abstract

Aims: Synthesis of 3-(2-amino-6-arylpyrimidin-4-yl)-4-hydroxy-1-methylquinolin-2(1H)-ones and estimation their anticancer activities on HepG2 and KB cancer lines. Background: Many derivatives of quinoline-2-on have been consider to synthesize and evaluate their biological properties by organic chemists due to their various biological effects, including antibacterial, antioxidant, anti-inflammatory, anticancer activities. Quinolinepyrimidine hybrid compounds exhibited various biological activities, such as antituberculosis, antibacterial, anticancer, antifungal, etc. The connection of 4-hydroxyquinoline-2-one with 2-amino-pyrimidine could initiate the new activities. Objective: α,β-Unsaturated ketones of 3-acetyl-4-hydroxy-N-methylquinolin-2-one were prepared. Novel 2-amino-6-aryl-4-(4′-hydroxy-Nmethylquinolin- 2′-on-3′-yl)pyrimidines have been synthesized by reaction of these corresponding α,β-unsaturated ketones with guanidine hydrochloride. Human hepatocellular carcinoma HepG2 and squamous cell carcinoma KB cancer lines were used for screening their cytotoxicity. Method: 3-Acetyl-4-hydroxy-N-methylquinolin-2-one was prepared from N-methylaniline and diethyl malonate. Reaction of (un)substituted benzaldehydes with this 4-hydroxyquinoline-2-one produced corresponding substituted α ,β-unsaturated ketones in the presence of piperidine as catalyst. 2-Amino-6-aryl-4-(4′-hydroxy-N-methylquinolin-2′-on-3′-yl)pyrimidines have been synthesized from these α,β-unsaturated ketones of 3-acetyl-4-hydroxy-N-methylquinolin-2-one by reaction of corresponding α ,β-unsaturated ketones with guanidine hydrochloride. All obtained pyrimidines were screened for anticancer activity using MTT bio-assay method. Result: Seven substituted (E)-4-hydroxy-3-(3-(aryl)acryloyl)-1-methylquinolin-2(1H)-ones were prepared and converted to corresponding substituted 2-amino-6-aryl-4-(4′-hydroxy-N-methylquinolin-2′-on-3′-yl)pyrimidines with yields of 58−74%. All the synthesized pyrimidines were screened for their in vitro anticancer activity against human hepatocellular carcinoma HepG2 and squamous cell carcinoma KB cancer lines. Compounds 6b and 6e had the best activity in the series, with IC50 values equal to 1.32 and 1.33 μM, respectively. ADMET properties showed that compounds 6b, 6e, and 6f possessed the drug-likeness behavior. Cross-docking results indicated that residues GLN778(A), DT8(C), DT9(D), DA12(F), and DG13(F) in the binding pocket as potential ligand binding hot-spot residues for compounds 6b, 6e, and 6f. Conclusion: New substituted 2-amino-6-aryl-4-(4′-hydroxy-N-methylquinolin-2′-on-3′-yl)pyrimidines were obtained and displayed significant inhibition against human hepatocellular carcinoma HepG2 and squamous cell carcinoma KB cancer lines.

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