Low-temperature deposition of nanocrystalline Al₂O₃ films by ion source-assisted magnetron sputtering

Ding, Ji Cheng,Zhang, Teng Fei,Mane, Rajaram S.,Kim, Kwang-Ho,Kang, Myung Chang,Zou, Chang Wei,Wang, Qi Min Elsevier 2018 Vacuum Vol.149 No.-

<P><B>Abstract</B></P> <P>In this paper, bipolar pulse reactive magnetron sputtering with ion source assisted deposition method has been utilized for the deposition of nanocrystalline alumina (Al<SUB>2</SUB>O<SUB>3</SUB>) films at the temperature of 300 °C onto silicon (111) wafers, and cemented carbide substrates. The influence of ion source power, i.e. 0, 1.0, 1.5 and 2.0 kW on the structure, morphology, compressive stress and mechanical properties of the Al<SUB>2</SUB>O<SUB>3</SUB> films were investigated. In absence of ion source power assistance, an amorphous Al<SUB>2</SUB>O<SUB>3</SUB> film was dominant at deposition temperature of 300 °C. With ion source assisted deposition, the crystalline γ-Al<SUB>2</SUB>O<SUB>3</SUB> films were obtained at the same conditions, suggesting an importance of ion source power in crystallinity development of metal oxide films obtained from magnetron sputtering deposition method. Images of surface morphology clearly demonstrated the difference in granular sizes of film surfaces prepared with and without ion source powers. With increasing ion source power from 1.0 to 2.0 kW, the micro-hardness and compressive stress of the films were increased from 7 GPa to 13 GPa and 0.3 GPa to 1.1 GPa, respectively. Results revealed that the reactive magnetron sputtering with the ion source assisted deposition was a simple and effective way to prepare nanocrystalline γ-Al<SUB>2</SUB>O<SUB>3</SUB> films at low temperature.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Al<SUB>2</SUB>O<SUB>3</SUB> films were synthesized by Ar ion source-assisted bipolar pulsed sputtering technique. </LI> <LI> Nanocrystalline Al<SUB>2</SUB>O<SUB>3</SUB> films were obtained at relatively low deposition temperature (300 °C) and low bias voltage conditions. </LI> <LI> The orientation and microstructure of the films can be adjusted by altering the ion source power. </LI> <LI> The synthesis approach of crystalline Al<SUB>2</SUB>O<SUB>3</SUB> films in this study is promising for large-scale industrial applications. </LI> </UL> </P>

ppGalNAc T1 as a Potential Novel Marker for Human Bladder Cancer

Ding, Ming-Xia,Wang, Hai-Feng,Wang, Jian-Song,Zhan, Hui,Zuo, Yi-Gang,Yang, De-Lin,Liu, Jing-Yu,Wang, Wei,Ke, Chang-Xing,Yan, Ru-Ping Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.11

Objectives: To investigate the effect of glycopeptide-preferring polypeptide GalNAc transferase 1 (ppGalNAc T1 ) targeted RNA interference (RNAi) on the growth and migration of human bladder carcinoma EJ cells in vitro and in vivo. Methods: DNA microarray assays were performed to determine ppGalNAc Ts(ppGalNAc T1-9) expression in human bladder cancer and normal bladder tissues. We transfected the EJ bladder cancer cell line with well-designed ppGalNAc T1 siRNA. Boyden chamber and Wound healing assays were used to investigate changes of shppGalNAc T1-EJ cell migration. Proliferation of shppGalNAc T1-EJ cells in vitro was assessed using [3H]-thymidine incorporation assay and soft agar colony formation assays. Subcutaneous bladder tumors in BALB/c nude mice were induced by inoculation of shppGalNAc T1-EJ cells and after inoculation diameters of tumors were measured every 5 days to determine gross tumor volumes. Results: ppGalNAc T1 mRNA in bladder cancer tissues was 11.2-fold higher than in normal bladder tissues. When ppGalNAc T1 expression in EJ cells was knocked down through transfection by pSUPER-shppGalNAc T1 vector, markedly reduced incorporation of [3H]-thymidine into DNA of EJ cells was observed at all time points compared with the empty vector transfected control cells. However, ppGalNAc T1 knockdown did not significantly inhibited cell migration (only 12.3%). Silenced ppGalNAc T1 expression significantly inhibited subcutaneous tumor growth compared with the control groups injected with empty vector transfected control cells. At the end of observation course (40 days), the inhibitory rate of cancerous growth for ppGalNAc T1 knockdown was 52.5%. Conclusion: ppGalNAc T1 might be a potential novel marker for human bladder cancer. Although ppGalNAc T1 knockdown caused no remarkable change in cell migration, silenced expression significantly inhibited proliferation and tumor growth of the bladder cancer EJ cell line.

An investigation of local structures and EPR spectra for Cu2+ and VO2+ in biochar

Chang-Chun Ding,Xiao-Hong Chu,Zhi-Xiang Fan,Jia Fu 한국물리학회 2020 Current Applied Physics Vol.20 No.2

Electron paramagnetic resonance (EPR) technology had been adopted to analyze the structures and properties of Cu2+ and VO2+ in Biochar (BG1 and BG2), but the local structural properties have not been clarified up to now. In present work, three possible structures (orthorhombically, rhombically and tetragonally elongated octahedra) are proposed for Cu2+ in BG1 and BG2 samples, and the former seems most reasonable in view of the best agreement between the theoretical EPR parameters based on the perturbation formulae and the experimental data. As for the VO2+ center, unlike the previous assignment of the tetragonally elongated [VO5]6− cluster based on the simple formulae of EPR parameters, presently proposed tetragonally compressed [VO6]8− cluster and the high order perturbation formulae of the EPR parameters yields good agreement with the observed values. This point is also supported by the d-d optical absorption 2B1g →2B2g for tetragonally compressed octahedral 3 d1 systems.

Comparative transcriptome analysis of tube feet of different colors in the sea urchin Strongylocentrotus intermedius

Jun Ding,Dan Yang,Yinan Wang,Weijie Zhang,Tingting Chen,Yaqing Chang 한국유전학회 2017 Genes & Genomics Vol.39 No.11

The Strongylocentrotus intermedius is an important commercially cultivated marine animal in China. In recent years, some individuals with diaphanous tube feet, rather than the normal red tube feet, have been observed among animals under cultivation; the basis of this phenotypic change is uncertain. In order to better understand the differences between two color tube feet of S. intermedius at the molecular level, we constructed four cDNA libraries from tube feet and coelomocytes of S. intermedius individuals with red or diaphanous tube feet. A total of 216,729,214 clean reads were assembled into 87,510 transcripts with an average size of 1677 bp. A BlastX search showed that 72,690 transcripts had significant matches in at least one target database. Expression profile analysis was performed on the four libraries and many differentially expressed genes were identified. Using gene enrichment analysis, several biological processes related to immune responses as well as immune-related candidate genes were identified. A total of 1694 genes were immune-related, and the genes expression of red tube feet were higher than that of diaphanous tube feet. In addition, 50,427 simple sequence repeats were obtained from the S. intermedius transcriptomes, while 32,650 and 42,264 single nucleotide polymorphisms were found in S. intermedius with diaphanous tube feet and red tube feet, respectively. These results provide valuable information for the future studies involving marker-assisted breeding and the studies of population genetics and genomics on S. intermedius.

Active and Passive Smoking, and Alcohol Drinking and Breast Cancer Risk in Chinese Women

Gao, Chang-Ming,Ding, Jian-Hua,Li, Su-Ping,Liu, Yan-Ting,Qian, Yun,Chang, Jun,Tang, Jin-Hai,Tajima, Kazuo Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.2

To evaluate the relation between smoking, alcohol drinking and risk of breast cancer in Chinese women, we conducted a case-control study with 669 cases and 682 population-based controls in Jiangsu Province of China. A structured questionnaire was used to elicit detailed information. Unconditional logistic regression analysis was performed to calculate odds ratios (ORs) and 95% confidence intervals (CIs). The results revealed that smoking, whether active or passive through the husband, was related to increased risk of breast cancer. The ORs (adjusted for age, menopausal status, educational levels, occupation, body mass index and income) were 3.55 (95%CI: 1.27-9.91) for active smoking and 1.47 (95%CI: 1.18-1.84) for passive smoking from husbands, respectively. A significant positive relationship was observed between breast cancer risk and the degree of husbands' smoking. There were significant increase trend in ORs with the daily smoked number of cigarettes of husbands, the passive smoking years from husbands and the pack-years of husbands' smoking (trend test: p=0.00003, 0.00013 and 0.0001, respectively). Alcohol consumption was also found to be a risk factor. The findings of this study in particular suggest that husbands' smoking increases risk of breast cancer in Chinese women.

Interfacial micromechanics modeling for bolted joints in ultra-precision machine tools

Yu Chang,Jianguo Ding,Hui Fan,Yuanyuan Ding,Hui Zhuang,Peng Chen 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.8

Bolted joints are widely adopted in various mechanical structures. However, the uncertainty and complexity of the contact surfaces affect accurate modeling. Herein, an interfacial micromechanics model is proposed to characterize the contact behaviors of bolted joints in an ultra-precision machine tool (UMT). The bolted joint is modeled as a virtual material layer with transversely isotropic behaviors, whose constitutive relation is identified by fractal theory. The proposed model accurately formulates the multi-scale contact characteristics and allows convenient integration with the structural dynamic modeling of UMT. Dynamic analysis of the simulation results and the experimental measurements in the time and frequency domains was conducted to identify the most sensitive factor affecting the tool tip vibration. On this basis, the structural optimization for the UMT was further implemented, which effectively reduced vibration by 15.5 %. The dynamic predictions were validated by modal and vibration response tests.

CCR6 Is a Predicting Biomarker of Radiosensitivity and Potential Target of Radiosensitization in Rectal Cancer

Hui Chang,Jia-wang Wei,Ya-lan Tao,Pei-rong Ding,Yun-fei Xia,Yuan-hong Gao,Wei-wei Xiao 대한암학회 2018 Cancer Research and Treatment Vol.50 No.4

Purpose This study aimed to explore the functions and mechanisms of C-C motif chemokine receptor 6 (CCR6), a gene associated with progression and metastasis of colorectal cancer (CRC), in radiosensitivity of rectal cancer (RC). Materials and Methods RNA sequencing and immunohistochemical analysis on CCR6 expression were performed in pretreatment tissues of RC patients exhibiting different therapeutic effects of radiotherapy. Colonogenic survival assay was conducted in different CRC cell lines to assess their radiosensitivity. And the impact of CCR6 expression on radiosensitivity was validated through RNA interference. The DNA damage repair (DDR) abilities of cell lines with different CCR6 expression were evaluated through immunofluorescence-based H2AX quantification. Results The CCR6 mRNA level was higher in patients without pathologic complete remission (pCR) than in those with pCR (fold changed, 2.11; p=0.004). High-level expression of CCR6 protein was more common in the bad responders than in the good responders (76.3% vs. 37.5%, p < 0.001). The CRC cell lines with higher CCR6 expression (LoVo and sw480) appeared to be more radioresistant, compared with the sw620 cell line which had lower CCR6 expression. CCR6 knockdown made the LoVo cells more sensitive to ionizing radiation (sensitization enhancement ratio, 1.738; p < 0.001), and decreased their DDR efficiency. Conclusion CCR6 might affect the RC radiosensitivity through DDR process. These findings supported CCR6 as a predicting biomarker of radiosensitivity and a potential target of radiosensitization for RC patients.

Implementation of Image Transmission Based on Vehicle-to-Vehicle Communication

Chang-hao Piao,Xiaoyue Ding,Jia He,장수현,Mingjie Liu 한국정보처리학회 2022 Journal of information processing systems Vol.18 No.2

Weak over-the-horizon perception and blind spot are the main problems in intelligent connected vehicles(ICVs). In this paper, a V2V image transmission-based road condition warning method is proposed to solvethem. The encoded road emergency images which are collected by the ICV are transmitted to the on-board unit(OBU) through Ethernet. The OBU broadcasts the fragmented image information including location and clockof the vehicle to other OBUs. To satisfy the channel quality of the V2X communication in different times, theoptimal fragment length is selected by the OBU to process the image information. Then, according to theposition and clock information of the remote vehicles, OBU of the receiver selects valid messages to decodethe image information which will help the receiver to extend the perceptual field. The experimental resultsshow that our method has an average packet loss rate of 0.5%. The transmission delay is about 51.59 ms inlow-speed driving scenarios, which can provide drivers with timely and reliable warnings of the roadconditions.

A New Modulation to Eliminate the Impact of Overlap Time for Three-Phase Current Source Converters

Ding Hao,Guo Xiaoqiang,He Meiling,Shi Changli,Jia Dongqiang,Chen Chao,Guerrero Josep M. 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.5

Three-phase current source converter tends to be attractive in future industrial applications. In order to ensure the continuous current for the dc-link inductor of the current source converter (CSC), an overlap time is mandatory for each switch, so as to avoid the over-voltage spike caused by the dc-link inductor current interruption. However, the overlap time results in the undesirable harmonics and current distortion, which fails to comply with the relevant IEEE Standard in terms of power quality. Especially, the negative infl uence caused by overlap time eff ect is much more serious with the increasing of the switching frequency applied to CSC. In order to solve the problem, the impact of the overlap time on the CSC is investigated, and the error resulted from the overlap time is clearly demonstrated. Based on the pulse equivalent principle and the Fourier analysis, the quantitative relationship between the current harmonic and the overlap time is obtained. And then, a new approach to eliminate the impact of overlap time on the CSC is proposed. Finally, the simulation and experimental results are carried out to verify the eff ectiveness of the proposed solution.

The Effect of Dietary Docosahexaenoic Acid Enrichment on the Expression of Porcine Hepatic Genes

Chang, W.C.,Chen, C.H.,Cheng, W.T.K.,Ding, S.T. Asian Australasian Association of Animal Productio 2007 Animal Bioscience Vol.20 No.5

To study the effect of dietary docosahexaenoic acid (DHA) enrichment on the expression of hepatic genes in pigs, weaned, crossbred pigs (30 d old) were fed diets supplemented with either 2% tallow or DHA oil for 18 d. Hepatic mRNA was extracted. Suppression subtractive hybridization was used to explore the hepatic genes that were specifically regulated by dietary DHA enrichment. After subtraction, we observed 288 cDNA fragments differentially expressed in livers from pigs fed either 2% DHA oil or 2% tallow for 18 d. After differential screening, 7 genes were found to be differentially expressed. Serum amyloid A protein 2 (SAA2) was further investigated because of its role in lipid metabolism. Northern analysis indicated that hepatic SAA2 was upregulated by dietary DHA enrichment (p<0.05). In a second experiment, feeding 10% DHA oil for 2d significantly increased the expression of SAA2 (compared to the 10% tallow group; p<0.05). The porcine SAA2 full length cDNA sequence was cloned and the sequence was compared to the human and mouse sequences. The homology of the SAA2 amino acid sequence between pig and human was 73% and between pig and mouse was 62%. There was a considerable difference in SAA2 sequences among these species. Of particular note was a deletion of 8 amino acids, in the pig compared to the human. This fragment is a specific characteristic for the SAA subtype that involved in acute inflammation reaction. Similar to human and mouse, porcine SAA2 was highly expressed in the liver of pigs. It was not detectable in the skeletal muscle, heart muscle, spleen, kidney, lung, and adipose tissue. These data suggest that SAA2 may be involved in mediation of the function of dietary DHA in the liver of the pig, however, the mechanism is not yet clear.