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Two new vernonioside K (1) and vernonioside L (2) and four known Δ7,9(11) stigmastane-type steroidal saponins—vernonioside B2 (3), vernoniacum B (4), vernonioside B1 (5), and vernoamyoside A (6)—were isolated from the leaves of Vernonia amygdalina. Their structures were determined by comprehensive spectroscopic analysis with one-dimensional nuclear magnetic resonance, two-dimensional nuclear magnetic resonance, and high-resolution mass spectrometry. All isolated compounds (1–6) were evaluated to determine their inhibitory effects on α-glucosidase and xanthine oxidase. Among them, two new compounds 1 and 2 showed significant inhibition of α-glucosidase with IC50 values of 78.56 ± 7.28 and 14.74 ± 1.57 (μM), respectively, comparable with acarbose as a positive control (127.53 ± 1.73 μM); none of these compounds inhibited xanthine oxidase activity. Compounds 1 and 2 are promising candidates for the development of antidiabetic agents from natural sources.

Active-matrix thin film transistors (TFTs) on glass substrates with a metal backplane, that are applied for flat panel displays, can be considered as a metamaterial absorber. In this study, TFT structures using doped silicon at source, drain, and channel terminals are investigated. These terminals are unchanged in size of 75 µm square and thickness of 5.3 µm. The electric conductivity is varied at the channel. The simulation results show that the structures with 500 S\m electric conductivity channels absorb incident electromagnetic waves with appropriately 100% at 758 GHz and a wide bandwidth of 20 GHz. As the electrical conductivity increases, the absorption and bandwidth are smaller at the main resonance peak. As the electrical conductivity decreases, the absorption falls at the resonance frequency, but the bandwidth is broadened. In addition, the electric field in the channel may influence the electron in the semiconductor and the electrical current between the source and drain terminals. By observing the electric field at the resonance frequency, we found that it is focused on the sides of channel terminals.

The leaves of Sanchezia Nobilis Hook. F grown in Vietnam are extracted with ethanol then distilled for ethanol retrievement under low pressure. The ethanol concentrate was shaken with n-hexane, then stirred with ethyl acetate and concentrated fractions were obtained. From the high ethyl acetate fraction, four compounds were isolated by normal phase and reversed-phase column chromatography. Their structures were determined by spectral analysis, including 1D and 2D NMR techniques (1H, 13C, DEPT, COZY, HSQC, HMBC and NOESY), High Resolution - Electrochewmical Ionization - Mass Spectroscopy (HR-ESI-MS), and identified by comparing with the recorded data. Among the isolated compounds, compound 2 (13-O-acetylfawcettimine) was first time isolated from nature; and mixture 1 (Fawcettidin), 3 (Apigenin) and 4 (Kaempferol) were first time isolated from the Sanchezia genus. The high ethyl acetate fraction of Sanchezia Nobilis Hook. F leaves were then evaluated for the anti-Helicobacter pylori (anti-HP) effect by determining the minimum inhibitory concentration method (MIC), which showed a good inhibitory, dose−dependent effect on Helicobacter pylori. The ethyl acetate fraction at 1/8 dilution showed a complete inhibitory effect on Helicobacter pylori for as long as 24 hours. At 1/128 dilution, the fraction only showed good results on inhibition after 24 hours.

Writing is an important aspect of language instruction since it is a necessary tool for students to develop their understanding of linguistic elements in practice. Nonetheless, when the teacher asked students to compose an English paragraph, several students struggled to put their thoughts into words appropriately. Not only do they struggle with syntax and vocabulary, but they also have trouble identifying and developing ideas. One of the weaknesses of certain students' writing ability is that the execution of concepts is not clear and consistent, and they still rely significantly on sample essays. Accordingly, in this research work, the researcher's purpose is to use the Think-Pair-Share technique to improve high school students' English writing performance. The main objective is to build a procedure for creating and evaluating the Think-Pair-Share (TPS) Technique, to assess the impact of the TPS on students' writing performance, and to collect feedback from them on the benefits and drawbacks of the TPS technique, as well as possible solutions to promote the use of TPS technique. The experimental research design was utilized to begin the study, along with many questionnaires and expert approaches. A total of 40 students were chosen at random, half of them were assigned to the experimental group (TPS technique) and the remainder to the control group (no TPS technique). All of the students were required to complete a writing pre-and post-test, but only the experimental group were required to complete the post-questionnaire. The findings show that using the TPS technique in the classroom can result in considerable improvements in writing performance. In addition, all of the students gave excellent feedback. Furthermore, the study offers some recommendations for eliminating the drawbacks of applying TPS in order to enhance the technique's potential and make it significantly more fascinating and useful.

Five compounds (1-5) were isolated from the leaves of Sanchezia nobilis collected in Nam Dinh province by chromatographic methods. These compounds were identified as: mangiferin (1), β-sitosterol (2), margaric acid (3), ursolic acid (4), oleanolic acid (5). Their structures were elucidated by spectroscopic methods, including mass spectrometry and nuclear magnetic resonance. These compounds were isolated from the leaves of Sanchezia nobilis for the first time. Screening of gastric and duodenal antiulcer effects on indomethacin induced gastric ulcer models showed that n-hexane fraction produced the highest antiulcer activity. Percentage inhibition of gastric ulceration of misoprostol was 22.86 %, while that of n-hexane fraction was 28.57 % (p < 0.05). Evaluation of gastric and duodenal antiulcer effects on acysteamine induced gastric ulcer models showed that this fraction was effective against gastric and duodenal ulcer (83.3 %), improved ulcer damage (54.17 %), significantly reduced the number of mean ulcer and ulcer index (2.00 ± 1.28) but it did not change the area of the ulcer.

Three undescribed dihydrostilbene glycosides, 3,5-dihydroxyldihydrostilbene 4′-O-[6′′-O-(4′′′-hydroxylbenzoyl)]-β-D-glucopyranoside (1), 3,5-dihydroxyldihydrostilbene 4′-O-(6′′-O-galloyl)-β-D-glucopyranoside (2), and 3,5-dihydroxyldihydrostilbene 4′-O-[6′′-O-(3′′′,4′′′-dimethoxyl)galloyl]-β-D-glucopyranoside (3), and seven known compounds, kaempferol 3-O-β-D-glucopyranoside (4), isoquercitrin (5), kaempferol 3-O-α-L-rhamnoside (6), quercitrin (7), (6S,9R)-roseoside (8), (-)-epicatechin 3-O-gallate (9), and (-)-epigallocatechin 3-O-gallate (10) have been isolated from the methanol extract of the leaves of Camellia sinensis var. assamica (J.W.Mast.) Kitam. (synnonym of Camellia assamica (Mast.) H.T.Chang) (Theaceae). Their structures were elucidated by spectroscopic methods (1 D-, 2 D-NMR) and mass spectra. All compounds were evaluated for cytotoxic activity against human oral cancer (CAL27) and human breast cancer (MDAMB231) cell lines. Compound 10 showed significant cytotoxic activity against CAL27 and MDAMB231 cell lines with IC50 values of 9.78 ± 0.25 and 3.27 ± 0.18 μM, respectively, compared to those of positive control, capecitabine (IC50 values of 8.20 ± 0.75 and 5.20 ± 0.89 μM).