Study on the Crystalline Structure and the Thermal Stability of Silver-oxide Films Deposited by Using Direct-current Reactive Magnetron Sputtering Methods

Gao Xiao-Yong,Feng Hong-Liang,Zhang Zeng-Yuan,Ma Jiao-Min 한국물리학회 2010 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.56 No.4

Silver-oxide (AgxO) films were deposited on glass substrates by direct-current reactive magnetron sputtering at different oxygen flux ratios (OFR = [O2]/[Ar]) and substrate temperatures (Ts). An X-ray diffraction analysis indicates that the AgxO films are biphased (Ag + Ag2O) when deposited at low OFR values and that Ag2O-dominated AgxO film can only be synthesized at higher OFR values, as con¯rmed by X-ray photoelectron spectroscopy. This result may be due to the Ag2O phase being preferably produced at high OFR value. The AgO phase is thermodynamically unsta-ble compared with the Ag2O phase. In order to further offer deep insight into the ¯lm's thermal stability, Ag2O-dominated AgxO ¯lms were thermally treated by using a rapid thermal processing technique at different annealing temperatures for different annealing times. The Ag2O phase is thermodynamically stable at temperatures below the threshold of the thermal decomposition tem-perature which approaches 175 ±C. The domination of the Ag2O phase in the AgxO film may be attributed to the chain reaction AgO → Ag2O ↔ Ag + O, AgO + Ag → Ag2O.

Development of a New Duplex Real-Time Polymerase Chain Reaction Assay for Detection of Dicer in G. gallus

( Xiao Lin Ji ),( Qi Wang ),( Yu Long Gao ),( Yong Qiang Wang ),( Li Ting Qin ),( Xiao Le Qi ),( Hong Lei Gao ),( Xiao Mei Wang ) 한국미생물 · 생명공학회 2013 Journal of microbiology and biotechnology Vol.23 No.5

Recently, there has been a growing body of evidence showing that cellular microRNAs (miRNAs) are involved in virus-host interactions. Numerous studies have focused on analyses of the expression profiles of cellular miRNAs, but the expression patterns of Dicer, which is responsible for the generation of miRNAs, have only rarely been explored in Gallus gallus. We developed a duplex realtime reverse transcriptase polymerase chain reaction (RTPCR) assay for the relative quantification of the mRNAs of Dicer and β-actin in G. gallus. To apply this method, the expression of Dicer in avian cells after infection with avian leukosis virus subgroup J (ALV-J) was detected using our established duplex real-time RT-PCR. The duplex realtime RT-PCR assay is sufficiently sensitive, specific, accurate, reproducible, and cost-effective for the detection of Dicer in G. gallus. Furthermore, this study, for the first time, demonstrated that ALV-J can induce differential expression of Dicer mRNA in the ALV-J-infected cells.

Analysis of the Optical Constants of Aluminum-doped Zinc-oxide Films by Using the Single-oscillator Model

Xiao-Yong Gao,Yan Liang,Qing-Geng Lin 한국물리학회 2010 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.57 No.4

A group of aluminum-doped zinc-oxide (AZO) films were prepared on glass substrates by directcurrent reactive magnetron sputtering at substrate temperatures (Ts) ranging from 170 ℃ to 210 ℃. The optical constants of the AZO films defined by using Caughy model were fitted in terms of a two-layer model by using the measured spectroscopic ellipsometric parameters. The refractive index dispersion data below the interband absorption edge of the AZO films were analyzed by using a single-oscillator model. The optical energy gap as-fitted by using the single-oscillator model demonstrated a blue and a red shift as T<SUB>s</SUB> increased from 170 ℃ to 200 ℃ and above 200 ℃, respectively. This could be attributed to a change in the free electron concentration, which was related to a change in the effective Al-doping efficiency. The calculated parameter β, related to the crystalline structure, indicated that the as-deposited AZO films fell into an ionic class even though β had a slight deviation from the ionic value. The β of the as-deposited AZO film at 200 ℃ largely remained in the range of ionic values, indicating a minimum deviation from the wurtzite structure. This denoted that Al is a very effective substitute for the zinc sites. Additionally, the calculated plasma frequency, hw<SUB>p</SUB>, remained in the violet region.

Structural and optical investigation of GaN grown by metal-organic Chemical Vapor Deposition

Xiao-Yong Gao,Liang-Yao Chen,Jing Li,Peng Zhou,Rong-Jun Zhang,Song-You Wang,Yue-Mei Yang,Yu-Xiang Zheng 한국물리학회 2004 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.44 No.32

Structural and optical properties of GaN grown on (0001)-oriented sapphire substrates by low pressure metal-organic chemical vapor deposition were investigated by XRD, ellipsometry, PL and other optical methods. The thickness of the GaN sample was about 1.5 m. Seen by XRD, the existence of the strong (0002) diraction peak with a very narrow FWHM value of 0.1 and the high order GaN (0004) diraction peak conrms a good quality of the GaN lms grown on sapphire substrate by using a multi-step growth procedure. Optical transparency of the GaN samples induces strong interference oscillations below E0 (3.44eV) in the measured dielectric function spectra and re ective spectra. In low temperature PL spectra, the red shift of the peak and decreased intensity of PL are visible. The former can be attributed to the involvement of band tail states, and the latter can be accounted for by the decreasing non-radiative recombination lifetime.

Structural and Optical Properties of RF Magnetron Reactively Sputtered Ag2O Film

Xiao-Yong Gao,Jiao-Min Ma,Chao Chen,Meng-Ke Zhao,Jin-Hua Gu,Jing-Xiao Lu 한국물리학회 2012 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.60 No.5

A series of <111> oriented Ag2O films was deposited onto glass substrates by using RF magnetron reactive sputtering at different flow ratios (FRs) of oxygen to argon. The Ag2O film deposited at FR = 0.667 was the best <111> oriented film due to dual contributions from both lattice strain and film stress. The films’ transmissivity of over 70% in the near-infrared region indicated that Ag2O films are not suitable for applications as transparent conductive films in the visible region. Ag2O films deposited at FRs from 0.467 to 0.800 had optical band gaps ranging from 3.266 eV to 3.107 eV. The redshift in the films’ absorption edge may be attributed to the decrease in the lattice strain with increasing in FR. A series of <111> oriented Ag2O films was deposited onto glass substrates by using RF magnetron reactive sputtering at different flow ratios (FRs) of oxygen to argon. The Ag2O film deposited at FR = 0.667 was the best <111> oriented film due to dual contributions from both lattice strain and film stress. The films’ transmissivity of over 70% in the near-infrared region indicated that Ag2O films are not suitable for applications as transparent conductive films in the visible region. Ag2O films deposited at FRs from 0.467 to 0.800 had optical band gaps ranging from 3.266 eV to 3.107 eV. The redshift in the films’ absorption edge may be attributed to the decrease in the lattice strain with increasing in FR.

Effect of the Oxygen Flux Ratio on the Structural and the Optical Properties of Silver-oxide Films Deposited by Using the Direct-current Reactive Magnetron Sputtering Method

Xiao-Yong Gao,Hong-Liang Feng,Zeng-Yuan Zhang,Jiao-Min Ma,Meng-Ke Zhao,Chao Chen,Jin-Hua Gu,Shi-E Yang,Yong-Sheng Chen,Jing-Xiao Lu 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.58 No.2

Using values of the oxygen flux ratio (OFR = [O2]/[Ar]) ranging from 0 to 0.5, authors deposited a series of silver-oxide (Ag_xO) films on glass substrates by direct-current reactive magnetron sputtering (DC sputtering) at a substrate temperature of 150 ℃. The effect of the OFR on the film’s structural and optical properties was systematically investigated by using X-ray diffractometry, scanning electron microscopy and spectrophotometry. The Ag_xO films deposited clearly show an evolution of the film’s phase structure from the biphased (Ag + Ag_2O) structure to the biphased (AgO + Ag_2O) structure and then to the single-phased (Ag_2O) structure as value of the OFR increases. Accordingly, the film’s surface morphology, related to the film’s crystalline structure, clearly changes from a loose and porous surface structure to a compact surface structure and then to a pyramid-like surface structure with increasing value of the OFR. The novel porous structure may be attributed to the interruption of the silver’s growth course by the AgO on the film’s surface. Notably, a single-phased Ag_2O film is deposited by DC-sputtering at OFR = 0.5 due to the dual effects of thermal decomposition of the AgO phase and a combination reaction of AgO and Ag to Ag_2O. The oscillations both in the film’s reflectivity and transmissivity spectra are strengthened with increasing OFR, indicating an evolution from the metallic behavior of the biphased (Ag + Ag_2O) film to the dielectric behavior of the biphased (Ag_2O + AgO) film and the single-phased Ag2O film. The fitted optical absorption edges of the Ag_2O and the Ag_xO films deposited at values of the OFR of 0.5 and 0.33 are approximately 2.43 eV and 2.34 eV, respectively. The absorption edges are closely related to the direct interband transitions.

Over-expression of SlWRKY39 leads to enhanced resistance to multiple stress factors in tomato

Xiao-chun Sun,Yong-feng Gao,Hui-rong Li,Shu-zhang Yang,Yong-sheng Liu 한국식물학회 2015 Journal of Plant Biology Vol.58 No.1

The WRKY transcription factors are one of the well-characterized classes of plant transcription factors, which participated in various biotic and abiotc stress responses. Previous study showed that there are 81 WRKY genes in tomato, wherein a number of SlWRKY genes including SlWRKY39 were significantly up-regulated under salt, drought stress and PstDC3000 infection. However little is known about their physiological role in tomato. In this study, by using a forward genetic approach, we demonstrated transgenic plants over-expressing SlWRKY39 showing enhanced resistance to multiple stress factors including PstDC3000, salt and drought. Transgenic plants accumulated higher level of proline and lower level of malonic dialdehyde. Compared with wild type, the expression of pathogenesis-related genes SlPR1, SlPR1a1 and environmental stress related genes SlRD22, SlDREB2A were up-regulated in the transgenic plants. These results indicated that SlWRKY39 is a positive regulatory component of tomato against biotic and abiotic stress probably via activating the expression of both pathogenesis-related genes and stress related genes.

Triterpenoids and Sterones from the Stem Bark of Ailanthus altissima

Xiao-Jiang Zhou,Min Xu,Xue-Song Li,Yue-Hu Wang,Ye Gao,Rui Cai,Yong-Xian Cheng 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.1

One new tirucallane-type triterpenoid, alianthusaltinin A (1), one new C29 sterone, alianthaltone A (2), and 12 known compounds have been isolated from the stem bark of Ailanthus altissima. The structures of new compounds were identified by means of spectroscopic methods. Compound 3 was isolated from natural sources for the first time, and compounds 4, 5, and 9 were isolated from this plant for the first time.

New Triterpenoids from the Fruits of Schisandra wilsoniana and Their Biological Activities

Gao, Xue-Mei,Li, Yun-Qi,Shu, Li-Dan,Shen, Yan-Qiong,Yang, Li-Ying,Yang, Liu-Meng,Zheng, Yong-Tang,Sun, Han-Dong,Xiao, Wei-Lie,Hu, Qiu-Fen Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.3

Investigation of an organic extract of the fruits Schisandra wilsoniana led to the isolation of two new highly oxygenated nortriterpenoids, named schilancidilactones V-W (1-2). Their structures were elucidated by spectroscopic evidence. Compounds 1-2 feature a double bond between C-7 and C-8 compared with related known nortriterpenoids isolated from the genus Schisandra. Compounds 1 and 2 were tested for their anti-HIV-1 activities and cytotoxicity. The results revealed that compounds 1 and 2 showed moderate anti-HIV-1 activities with $EC_{50}$ 3.05 and 2.87 ${\mu}g/mL$, respectively, and compound 1 showed high cytotoxicity against KB and MDA-MB-231 cell with $IC_{50}$ values of 3.18 and 5.22 ${\mu}M$, respectively.

Downregulation of Cdk1 and CyclinB1 Expression Contributes to Oridonin-induced Cell Cycle Arrest at G₂/M Phase and Growth Inhibition in SGC-7901 Gastric Cancer Cells

Gao, Shi-Yong,Li, Jun,Qu, Xiao-Ying,Zhu, Nan,Ji, Yu-Bin Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.15

Background: Oridonin isolated from Rabdosia rubescens, a plant used to treat cancer in Chinese folk medicine, is one of the most important antitumor active ingredients. Previous studies have shown that oridonin has antitumor activities in vivo and in vitro, but little is known about cell cycle effects of oridonin in gastric cancer. Materials and Methods: MTT assay was adopted to detect the proliferation inhibition of SGC-7901 cells, the cell cycle was assessed by flow cytometry and protein expression by Western blotting. Results: Oridonin could inhibit SGC-7901 cell proliferation, the $IC_{50}$ being $15.6{\mu}M$, and blocked SGC-7901 cell cycling in the $G_2/M$ phase. The agent also decreased the protein expression of cyclinB1 and CDK1. Conclusions: Oridonin may inhibit SGC-7901 growth and block the cells in the $G_2/M$ phase by decreasing Cdk1 and cyclinB1 proteins.