Effect of oxygen partial pressure on the performance of homojunction amorphous In-Ga-Zn-O thin-film transistors.

In this study, the homojunction thin-film transistors (TFTs) with amorphous indium gallium zinc oxide (a-IGZO) as active channel layers and source/drain electrodes were fabricated by RF magnetron sputtering. The effect of oxygen partial pressure on the phase, microstructure, optical and electrical properties of IGZO thin films was investigated. The results showed that amorphous IGZO thin films always exhibit a high transmittance above 90% and wide band gaps of around 3.9 eV. The resistivity increases as the IGZO thin films are deposited at a higher oxygen partial pressure due to the depletion of oxygen vacancies. In addition, the electrical behaviors in homojunction IGZO TFTs were analyzed. When the active channel layers were deposited with an oxygen partial pressure of 1.96%, the homojunction IGZO TFTs exhibited optimal transfer and output characteristics with a field-effect mobility of 13.68 cm2V-1s-1. Its sub-threshold swing, threshold voltage and on/off ratio are 0.6 V/decade, 0.61 V and 107, respectively.

Purity Assessment of Aryltetralin Lactone Lignans by Quantitative 1H Nuclear Magnetic Resonance.

In the present work, a quantitative 1H Nuclear Magnetic Resonance (qHNMR) was established for purity assessment of six aryltetralin lactone lignans. The validation of the method was carried out, including specificity, selectivity, linearity, accuracy, precision, and robustness. Several experimental parameters were optimized, including relaxation delay (D1), scan numbers (NS), and pulse angle. 1,4-Dinitrobenzene was used as internal standard (IS), and deuterated dimethyl sulfoxide (DMSO-d6) as the NMR solvent. The purities were calculated by the area ratios of H-2,6 from target analytes vs. aromatic protons from IS. Six aryltetralin lactone lignans (deoxypodophyllotoxin, podophyllotoxin, 4-demethylpodophyllotoxin, podophyllotoxin-7'-O-ß-d-glucopyranoside, 4-demethylpodophyllotoxin-7'-O-ß-d-glucopyranoside, and 6''-acetyl-podophyllotoxin-7'-O-ß -d-glucopyranoside) were analyzed. The analytic results of qHNMR were further validated by high performance liquid chromatography (HPLC). Therefore, the qHNMR method was a rapid, accurate, reliable tool for monitoring the purity of aryltetralin lactone lignans.

Extractions of oil from Descurainia sophia seed using supercritical CO2, chemical compositions by GC-MS and evaluation of the anti-tussive, expectorant and anti-asthmatic activities.

Descurainia sophia is widely distributed in China and is one of the most troublesome annual weeds. It has diverse medicinal usage. D. sophia has abundant oil, making it an important oil plant in China. The main goal of this study was to obtain the maximum yield of the oil by an optimal selection of supercritical fluid extraction parameters. According to the central composite design and response surface methodology for supercritical fluid extraction method, a quadratic polynomial model was used to predict the yield of D. sophia seed oil. A series of runs was performed to assess the optimal extraction conditions. The results indicated that the extraction pressure had the greatest impact on oil yield within the range of the operating conditions studied. A total of approximately 67 compounds were separated in D. sophia seed oil by GC-MS, of which 51 compounds represented 98.21% of the total oils, for the first time. This study was also aimed at evaluating the anti-asthmatic, anti-tussive and expectorant activities in vivo of D. sophia seed oil which supplied for further research on bioactive constituents and pharmacological mechanisms.

Ethyl ent-15α-[(2-nitro-benz-yloxy)meth-yl]-16-oxobeyeran-20-oate.

In the title compound, C(30)H(41)NO(6), the three six-membered rings adopt chair conformations and the stereochemistry of the A/B and B/C ring junctions are trans. The five-membered ring D adopts an envelope conformation, with the methyl-ene C atom as the flap. The title compound was synthesized via esterification, Tollens reaction, 1,5-hydride shift from the natural tetracyclic diterpenoid isosteviol.

Ethyl ent-15α-[(2-meth-oxy-benz-yloxy)meth-yl]-16-oxobeyeran-20-oate.

The title compound, C(31)H(44)O(5), was synthesized from isostev-iol (systematic name: ent-16-ketobeyeran-19-oic acid). In the mol-ecule, the three six-membered rings adopt chair conformations and the stereochemistry of the A/B and B/C ring junctions are trans. The five-membered ring D adopts an envelope conformation with the methyl-ene C atom as the flap.

Structurally diverse biflavonoids from Dysosma versipellis and their bioactivity.

Five pairs of new biflavonoid enantiomers, (±)-dysosmabiflavonoids A-E (1-5), two new biflavonoids, dysosmabiflavonoids F-G (6-7), and four biosynthetically related precursors (8-11) were isolated from the roots and rhizomes of Dysosma versipellis. Their structures were elucidated by extensive spectroscopic analysis, including HR-ESI-MS and 2D NMR. Their absolute configurations were determined by comparison of the calculated and experimental ECD spectra. All isolated compounds were evaluated for AChE inhibitory activity. Compounds 6 and 7 exhibited more potent inhibitory activities with IC50 values of 1.42 and 0.73 µM, respectively, than their biosynthetically related precursors kaempferol (8, 17.90 µM) and quercetin (9, 3.96 µM). The preliminary structure-activity relationship study indicated that the connection mode of biflavonoid subunits, oxidation degree of the C ring, and 3,4-dihydroxy group of the B ring were important structural factors for AChE inhibitory activity. Racemates 1-5 and their corresponding levorotatory and dextrorotatory enantiomers were tested for their potential to impede the generation of NO in lipopolysaccharide-stimulated RAW264.7 cells, and their mushroom tyrosinase inhibitory effect. Racemate 1 displayed more potent mushroom tyrosinase inhibitory activity (IC50, 28.27 µM) than the positive control kojic acid (IC50, 32.59 µM). D. versipellis may have therapeutic potential for melanogenesis disorders and neurodegenerative diseases.

In-Sn-Zn Oxide Nanocomposite Films with Enhanced Electrical Properties Deposited by High-Power Impulse Magnetron Sputtering.

In-Sn-Zn oxide (ITZO) nanocomposite films have been investigated extensively as a potential material in thin-film transistors due to their good electrical properties. In this work, ITZO thin films were deposited on glass substrates by high-power impulse magnetron sputtering (HiPIMS) at room temperature. The influence of the duty cycle (pulse off-time) on the microstructures and electrical performance of the films was investigated. The results showed that ITZO thin films prepared by HiPIMS were dense and smooth compared to thin films prepared by direct-current magnetron sputtering (DCMS). With the pulse off-time increasing from 0 µs (DCMS) to 2000 µs, the films' crystallinity enhanced. When the pulse off-time was longer than 1000 µs, In2O3 structure could be detected in the films. The films' electrical resistivity reduced as the pulse off-time extended. Most notably, the optimal resistivity of as low as 4.07 × 10-3 Ω·cm could be achieved when the pulse off-time was 2000 µs. Its corresponding carrier mobility and carrier concentration were 12.88 cm2V-1s-1 and 1.25 × 1020 cm-3, respectively.

Phenolic constituents from the root bark of Morus alba L. and their cardioprotective activity in vitro.

A flavanone C-glycoside, steppogenin-5'-C-ß-D-glucopyranoside, six prenylated 2-arylbenzofuran derivatives, moracin O-3″-O-ß-D-glucopyranoside, moracin O-3'-O-ß-D-xylopyranoside, moracin P-2″-O-ß-D-glucopyranoside, moracin P-3'-O-ß-D-glucopyranoside, moracin P-3'-O-α-L-arabinopyranoside and moracin P-3'-O-[ß-D-glucopyranosyl-(1 â†’ 2)]-α-L-arabinopyranoside, two phenolic acids, 2,4-dihydroxy-5-(4-hydroxybenzyl) benzoic acid and 2,4-dihydroxy-5-(3,4-dihydroxybenzyl) benzoic acid, as well as three known compounds, moracinoside C, moracin O, and moracin P were isolated from the root bark of Morus alba L. Their structures were ascertained on the basis of spectroscopic evidence. The protective effects of the compounds against doxorubicin-induced cardiomyopathy in H9c2 cells was investigated in vitro. Of all of the isolated compounds, moracin P-3'-O-ß-D-glucopyranoside, moracin O and moracin P had a strong protective influence against doxorubicin-induced cell death with EC50 values of 9.5 ± 2.6, 4.5 ± 1.3, and 8.8 ± 2.4 µM, respectively.

Lignanamides with potent antihyperlipidemic activities from the root bark of Lycium chinense.

Seven new lignanamides, lyciumamides D-J (1-4 and 9-11), together with nine known analogues (5-8 and 12-16), were isolated from the root bark of Lycium chinense. The structures of the isolated compounds were elucidated on the basis of NMR spectroscopic and HRESIMS data. All isolated compounds were evaluated for antihyperlipidemic activities in HepG2 cells. The primary structure-activity relationships were discussed.

Three new sulphur glycosides from the seeds of Descurainia sophia.

Three new sulphur glycosides, raphanuside B-D (1-3), together with a known sulphur glycoside, raphanuside (4) were isolated from the decoction of the seeds of Descurainia sophia (L.) Webb ex Prantl, and the compound 4 was reported for the first time from this plant. Their structures were identified by means of UV, IR, 1D, 2D NMR (HSQC, HMBC and NOESY) and HR-ESI-MS spectroscopic data.