Polishing Characteristics of MnO2 Polishing Slurry on the Si-face of SiC Wafer

Tao Yin,Tosiro Doi,구로가와슈헤이,Zhao zhong Zhou,Kai ping Feng 한국정밀공학회 2018 International Journal of Precision Engineering and Vol.19 No.12

To realize an efficient and high-quality chemical-mechanical polishing process for the surface of a SiC wafer, a new type of MnO2 slurry is developed employing the multi-valence and oxidation-reduction characteristics of MnO2 particles. This slurry is utilized to polish the Si-face of SiC wafers. In this paper, the influences of the polishing particle concentration and the pH of slurry on MRR are analyzed, the polishing performance of the MnO2 slurry is studied, and the polishing mechanism of the MnO2 slurry on the SiC wafer is determined. The polishing mechanism of the MnO2 slurry is verified by selecting commonly used additives, such as KMnO4, and the influence of the additive amount on the MRR is analyzed. Finally, the surface morphology of the material after polishing is observed with analytical instruments. The experimental results show that the MRR of the MnO2 slurry is highly dependent on the pH value of the slurry. The MnO2 particles tend to convert into MnO4 - ions in an alkaline environment, and the strong oxidizing property of MnO4 - ions greatly improves the polishing efficiency. As the MnO4 - ion concentration increases, the MRR can reach over 600 nm/ h, and an ultra-smooth surface with a surface.

A high performance of BPhen-based white organic light-emitting devices with a dual-emitting layer and its electroluminescent spectral property

Hua-Ping Lin,Fan Zhou,Jun Li,Xiao-Wen Zhang,Dong-Bin Yu,Liang Zhang,Xue-Yin Jiang,Zhi-Lin Zhang 한국공업화학회 2011 Journal of Industrial and Engineering Chemistry Vol.17 No.4

This work demonstrated the fabrication of white organic light-emitting devices (WOLEDs) using a dual emitting layer (d-EML) consisting of blue and ‘white’ emitters. In this d-EML system, the blue emitter not only emits but also assists the incomplete energy transfer. More importantly, it behaves as an effective trapping site for holes, which contributes to the efficient recombination of electron–hole pairs. The d-EML was constructed between the hole-transmitting layer (HTL) and the electron-transmitting layer (ETL) of Alq3 and BPhen. The thickness of the blue emitter used in the d-EML devices has an important effect on chromaticity and efficiency. Through the optimization of device structure, the reasonable white emission with Commission Internationale de L’Eclairage (CIE) color coordinates of (0.33, 0.33) and little color shift was obtained. The device showed an applicable luminance with its maximum luminance of 22,874 cd/m2 at a driving voltage of 16 V. The maximum luminance efficiency was achieved 8.10 cd/A,and the maximum power efficiency was reached 5.07 Lm/W. The result is explained with the help of the excitons generation and diffusion theory. According to the theory of excitons generation and diffusion,an equation has been set up which concerns electroluminescent spectra to the thickness of the two emitters and to the exciton diffusion length.

Optimal Monochromatic Imaging of Spectral Computed Tomography Potentially Improves the Quality of Hepatic Vascular Imaging

Xiao-Ping Yin,Bu-Lang Gao,Cai-Ying Li,Huan Zhou,Liang Zhao,Ya-Ting Zheng,Yong-Xia Zhao 대한영상의학회 2018 Korean Journal of Radiology Vol.19 No.4

Objective: To investigate the efficiency of spectral computed tomography (CT) optimal monochromatic images in improving imaging quality of liver vessels. Materials and Methods: The imaging data of 35 patients with abdominal CT angiography were retrospectively analyzed. Hepatic arteries, portal veins, and hepatic veins were reconstructed with mixed energy (quality check, QC), 70 keV and optimal monochromatic mode. Comparative parameters were analyzed including CT value, image noise (IN), contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR), and subjective qualitative analysis. Results: The optimal monochromatic value for assessment of the common hepatic artery, portal vein, and hepatic vein ranged between 49 keV and 53 keV, with a mean of 51 keV. There were statistically significant differences (p < 0.001) among the optimal monochromatic, 70 keV and QC images with regards to the hepatic vascular CT value, IN, CNR, SNR, and subjective qualitative score. CNR of the common hepatic artery in the optimal monochromatic, 70 keV and QC groups was 24.6 ± 10.9, 18.1 ± 8.3, and 11.6 ± 4.6, respectively (p < 0.001) with subjective scores of 4.7 ± 0.2, 4.0 ± 0.3, and 3.6 ± 0.4, respectively (p < 0.001). CNR of the hepatic portal vein was 6.9 ± 2.7, 4.3 ± 1.9, and 3.0 ± 2.1, respectively (p < 0.001) with subjective scores of 4.5 ± 0.3, 3.9 ± 0.4, and 3.3 ± 0.3, respectively (p < 0.001). CNR of the hepatic vein was 5.7 ± 2.3, 4.2 ± 1.9, and 2.7 ± 1.4, respectively with subjective scores of 4.3 ± 0.3, 3.8 ± 0.4, and 3.2 ± 0.3, respectively (p < 0.001). Conclusion: Optimal monochromatic images can lead to improvement in the imaging parameters and optimization of the image quality of the common hepatic artery, hepatic portal vein and hepatic vein compared with conventional mixed kV and with 70 keV datasets.

Efficient hole injection in blue organic light-emitting devices by using a double hole injection layer to improve chromaticity and electrical characteristics

Hua-Ping Lin,Fan Zhou,Xiao-Wen Zhang,Dong-Bin Yu,Jun Li,Liang Zhang,Xue-Yin Jiang,Zhi-Lin Zhang 한국물리학회 2011 Current Applied Physics Vol.11 No.3

A double hole injection layer consisting of Ag_2O//MoO_x was applied to a 4,40-bis (2,2-diphenylvinyl)-1,10-biphenyl-based blue organic light-emitting device (OLED). The hole current injection of the devicewas improved and the performance of the blue OLED was enhanced. We have observed that the insertion of such double layer leads to a striking improvement in chromaticity and electrical characteristics. This device showed much better chromaticity and less current-induced color shift as compared to the corresponding single hole injection layer counterparts. Using this strategy, a striking improvement in the electrical properties with lower driving voltage, higher power efficiency and a weak current-induced fluorescence quenching was achieved. This could be explained by the fact that an interlayer of Ag_2O//MoO_x provided a stepped energy level which greatly facilitated hole injection and hence enhanced injection current. The result is verified by using the J―V curves of ‘only’ devices and further explained with the help of Fowler-Nordheim (F-N) tunneling theory.

MicroRNA-214 Regulates the Acquired Resistance to Gefitinib via the PTEN/AKT Pathway in EGFR-mutant Cell Lines

Wang, Yong-Sheng,Wang, Yin-Hua,Xia, Hong-Ping,Zhou, Song-Wen,Schmid-Bindert, Gerald,Zhou, Cai-Cun Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.1

Patients with non-small cell lung cancer (NSCLC) who have activating epidermal growth factor receptor (EGFR) mutations derive clinical benefit from treatment with EGFR-tyrosine kinase inhibitors ((EGFR-TKIs)-namely gefitinib and erlotinib. However, these patients eventually develop resistance to EGFR-TKIs. Despite the fact that this acquired resistance may be the result of a secondary mutation in the EGFR gene, such as T790M or amplification of the MET proto-oncogene, there are other mechanisms which need to be explored. MicroRNAs (miRs) are a class of small non-coding RNAs that play pivotal roles in tumorigenesis, tumor progression and chemo-resistance. In this study, we firstly successfully established a gefitinib resistant cell line-HCC827/GR, by exposing normal HCC827 cells (an NSCLC cell line with a 746E-750A in-frame deletion of EGFR gene) to increasing concentrations of gefitinib. Then, we found that miR-214 was significantly up-regulated in HCC827/GR. We also showed that miR-214 and PTEN were inversely expressed in HCC827/GR. Knockdown of miR-214 altered the expression of PTEN and p-AKT and re-sensitized HCC827/GR to gefitinib. Taken together, miR-214 may regulate the acquired resistance to gefitinib in HCC827 via PTEN/AKT signaling pathway. Suppression of miR-214 may thus reverse the acquired resistance to EGFR-TKIs therapy.

Long-term exposure to moderate noise induces neural plasticity in the infant rat primary auditory cortex

Chenchen Xia,Manli Yin,Ping Pan,Fanghao Fang,You Zhou,Yonghua Ji 한국통합생물학회 2019 Animal cells and systems Vol.23 No.4

Previous studies have reported that rearing infant rat pups in continuous moderate-level noise delayed the formation of topographic representational order and the refinement of response selectivity in the primary auditory (A1) cortex. The present study further verified that exposure to long-term moderate-intensity white noise (70 dB sound pressure level) from postnatal day (P) 12 to P30 elevated the hearing thresholds of infant rats. Compared with age-matched control rats, noise exposure (NE) rats had elevated hearing thresholds ranging from low to high frequencies, accompanied by decreased amplitudes and increased latencies of the two initial auditory brainstem response waves. The power of raw local field potential oscillations and high-frequency β oscillation in the A1 cortex of NE rats were larger, whereas the power of high-frequency γ oscillation was smaller than that of control rats. In addition, the expression levels of five glutamate receptor (GluR) subunits in the A1 cortex of NE rats were decreased with laminar specificity. These results suggest that the altered neural excitability and decreased GluR expression may underlie the delay of functional maturation in the A1 cortex, and may have implications for the treatment of hearing impairment induced by environmental noise.

Suppression of bias stress-induced degradation of pentacene-TFT using MoOx interlayer

Jun Li,Hua-Ping Lin,Fang Zhou,Wen-Qing Zhu,Xue-Yin Jiang,Zhi-Lin Zhang 한국물리학회 2012 Current Applied Physics Vol.12 No.1

The bias stress effect in pentacene thin-film transistors (TFTs) with and without MoOx interlayer was characterized. The device without MoOx interlayer showed a large threshold voltage shift of 5.1 V after stressing with a constant gate-source voltage of 40 V for 10000 s, while at the same condition, the device with MoOx interlayer showed a low threshold voltage shift of 1.9 V. The results can be attributed to the stable interface between MoOx/pentacene and small contact resistance change for the device with MoOx/Cu electrode. Pentacene-TFTs with MoOx interlayer showed a high field-effect mobility of 0.61 cm2/V s and excellent bias stability, which could be a significant step toward the commercialization of OTFT technology.

Efficacy and Safety of Pulse Magnetic Therapy System in Insomnia Disorder: A Multicenter, Randomized, Double-Blind, Placebo-Controlled Trial

Liao Jiwu,Wang Sisi,Zhou Borong,Liang Wei,Ma Ping,Lin Min,Lin Weisen,Li Congrui,Zhang Xiaotao,Li Hongyao,Cui Yin,Hu Jiajia,Qin Yuanyi,Deng Yanhua,Fu Aibing,Zhu Tianhua,Zhang Shanlian,Qu Yunhong,Xing L 대한신경정신의학회 2023 PSYCHIATRY INVESTIGATION Vol.20 No.6

Objective This study’s objective is to assess the efficacy and safety of Pulsed Magnetic Therapy System (PMTS) in improving insomnia disorder.Methods Participants with insomnia disorder were randomly assigned to receive either PMTS or sham treatment for four weeks (n= 153; PMTS: 76, sham: 77). Primary outcomes are the Insomnia Severity Index (ISI) scores at week 0 (baseline), 1, 2, 3, 4 (treatment), and 5 (follow-up). Secondary outcomes are the Pittsburgh Sleep Quality Index at baseline and week 4, and weekly sleep diary-derived values for sleep latency, sleep efficiency, real sleep time, waking after sleep onset, and sleep duration.Results The ISI scores of the PMTS group and the sham group were 7.13±0.50, 11.07±0.51 at week 4, respectively. There was a significant group×time interaction for ISI (F3.214, 485.271=24.25, p<0.001, ηp 2=0.138). Only the PMTS group experienced continuous improvement throughout the study; in contrast, the sham group only experienced a modest improvement after the first week of therapy. At the end of the treatment and one week after it, the response of the PMTS group were 69.7% (95% confidence interval [CI]: 58.6%–79.0%), 75.0% (95% CI: 64.1%–83.4%), respectively, which were higher than the response of the sham group (p<0.001). For each of the secondary outcomes, similar group×time interactions were discovered. The effects of the treatment persisted for at least a week.Conclusion PMTS is safe and effective in improving insomnia disorders.

Elucidations of weak microcavity effect and improved pixel contrast ratio in Si-based top-emitting organic light-emitting diode

Xiao-Wen Zhang,Hua-Ping Lin,Jun Li,Fan Zhou,Bin Wei,Xue-Yin Jiang,Zhi-Lin Zhang 한국물리학회 2012 Current Applied Physics Vol.12 No.5

Microcavity effect and pixel contrast ratio (PCR) are key issues for top-emitting organic light-emitting diode (TOLED). Si and Ag are two widely used reflective anodes for constructing effective TOLEDs. The mechanism contributing to microcavity effect and PCR has been clarified by using conventional optoelectronic theory. Consequently, the differences of microcavity effect and PCR between Si-based and Agbased TOLEDs are discovered. Our results indicate that the Si-based TOLED possesses weak microcavity effect and improved PCR in comparison with Ag-based device. This is resulted from the low reflectivity and less reflective phase change of Si. The weak microcavity effect in Si-based TOLED also contributes to negligible variation of electroluminescent spectra with viewing angles and low device efficiency. Furthermore, Si-based TOLED shows rather high PCR which is about quintuple that of Ag-based device. Microcavity effect and pixel contrast ratio (PCR) are key issues for top-emitting organic light-emitting diode (TOLED). Si and Ag are two widely used reflective anodes for constructing effective TOLEDs. The mechanism contributing to microcavity effect and PCR has been clarified by using conventional optoelectronic theory. Consequently, the differences of microcavity effect and PCR between Si-based and Agbased TOLEDs are discovered. Our results indicate that the Si-based TOLED possesses weak microcavity effect and improved PCR in comparison with Ag-based device. This is resulted from the low reflectivity and less reflective phase change of Si. The weak microcavity effect in Si-based TOLED also contributes to negligible variation of electroluminescent spectra with viewing angles and low device efficiency. Furthermore, Si-based TOLED shows rather high PCR which is about quintuple that of Ag-based device.

Ginsenoside Rg1 activates ligand-independent estrogenic effects via rapid estrogen receptor signaling pathway

Gao, Quan-Gui,Zhou, Li-Ping,Lee, Vien Hoi-Yi,Chan, Hoi-Yi,Man, Cornelia Wing-Yin,Wong, Man-Sau The Korean Society of Ginseng 2019 Journal of Ginseng Research Vol.43 No.4

Background: Ginsenoside Rg1 was shown to exert ligand-independent activation of estrogen receptor (ER) via mitogen-activated protein kinase-mediated pathway. Our study aimed to delineate the mechanisms by which Rg1 activates the rapid ER signaling pathways. Methods: ER-positive human breast cancer MCF-7 cells and ER-negative human embryonic kidney HEK293 cells were treated with Rg1 ($10^{-12}M$, $10^{-8}M$), $17{\beta}$-estradiol ($10^{-8}M$), or vehicle. Immunoprecipitation was conducted to investigate the interactions between signaling protein and ER in MCF-7 cells. To determine the roles of these signaling proteins in the actions of Rg1, small interfering RNA or their inhibitors were applied. Results: Rg1 rapidly induced $ER{\alpha}$ translocation to plasma membrane via caveolin-1 and the formation of signaling complex involving linker protein (Shc), insulin-like growth factor-I receptor, modulator of nongenomic activity of ER (MNAR), $ER{\alpha}$, and cellular nonreceptor tyrosine kinase (c-Src) in MCF-7 cells. The induction of extracellular signal-regulated protein kinase and mitogen-activated protein kinase kinase (MEK) phosphorylation in MCF-7 cells by Rg1 was suppressed by cotreatment with small interfering RNA against these signaling proteins. The stimulatory effects of Rg1 on MEK phosphorylation in these cells were suppressed by both PP2 (Src kinase inhibitor) and AG1478 [epidermal growth factor receptor (EGFR) inhibitor]. In addition, Rg1-induced estrogenic activities, EGFR and MEK phosphorylation in MCF-7 cells were abolished by cotreatment with G15 (G protein-coupled estrogen receptor-1 antagonist). The increase in intracellular cyclic AMP accumulation, but not Ca mobilization, in MCF-7 cells by Rg1 could be abolished by G15. Conclusion: Ginsenoside Rg1 exerted estrogenic actions by rapidly inducing the formation of ER containing signalosome in MCF-7 cells. Additionally, Rg1 could activate EGFR and c-Src ER-independently and exert estrogenic effects via rapid activation of membrane-associated ER and G protein-coupled estrogen receptor.