Effects of polymer surface energy on morphology and properties of silver nanowire fabricated via nanoimprint and E-beam evaporation

Zhao, Zhi-Jun,Hwang, Soon Hyoung,Jeon, Sohee,Jung, Joo-Yun,Lee, Jihye,Choi, Dae-Geun,Choi, Jun-Hyuk,Park, Sang-Hu,Jeong, Jun-Ho Elsevier 2017 APPLIED SURFACE SCIENCE - Vol.420 No.-

<P><B>Abstract</B></P> <P>In this paper, we demonstrate that use of different nanoimprint resins as a polymer pattern has a significant effect on the morphology of silver (Ag) nanowires deposited via an E-beam evaporator. RM-311 and Ormo-stamp resins are chosen as a polymer pattern to form a line with dimensions of width (100nm)×space (100nm)×height (120nm) by using nanoimprint lithography (NIL). Their contact angles are then measured to evaluate their surface energies. In order to compare the properties of the Ag nanowires deposited on the various polymer patterns with different surface energies, hydrophobic surface treatment of the polymer pattern surface is implemented using self-assembled monolayers. In addition, gold and aluminum nanowires are fabricated for comparison with the Ag nanowires, with the differences in the nanowire morphologies being determined by the different atomic properties. The monocrystalline and polycrystalline structures of the various Ag nanowire formations are observed using transmission electron microscopy. In addition, the melting temperatures and optical properties of four kinds of Ag nanowire morphologies deposited on various polymer patterns are evaluated using a hot plate and an ultraviolet-visible (UV–vis) spectrometer, respectively. The results indicate that the morphology of the Ag nanowire determines the melting temperature and the transmission. We believe that these findings will greatly aid the development of NIL, along with physical evaporation and chemical deposition techniques, and will be widely employed in optics, biology, and surface wettability applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Ag nanowires with various morphologies deposited on polymer patterns with different surface energies were fabricated via nanoimprint and e-beam evaporation. </LI> <LI> The formation mechanism behind the different morphologies of the Ag nanowires deposited on the polymer patterns with different surface energies was explained and confirmed. </LI> <LI> The morphologies of Ag nanowires have an important effect on their transmission and melting temperature. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Modulation of Drug Resistance in Ovarian Cancer Cells by Inhibition of Protein Kinase C-alpha (PKC-α) with Small Interference RNA (siRNA) Agents

Zhao, Li-Jun,Xu, Heng,Qu, Jun-Wei,Zhao, Wan-Zhou,Zhao, Yi-Bing,Wang, Jin-Hua Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.8

Objective: To determine whether silence of $PKC-{\alpha}$ expression by small interference RNA (siRNA) might regulate MDR1 expression and reverse chemoresistance of ovarian cancer. Methods: We measured gene and protein expression of MDR1 and $PKC-{\alpha}$ in ovarian cancer cells and assessed their correlation with cell drug resistance. We also examined whether blocking $PKC-{\alpha}$ by RNA interference (RNAi) affected MDR1 expression and reversed drug resistance in drug sensitivity tests. Results: The drug resistance cell lines, OV1228/DDP and OV1228/Taxol, had higher gene and protein expression of MDR1 and $PKC-{\alpha}$ than their counterpart sensitive cell line, OV1228. SiRNA depressed $PKC-{\alpha}$ gene protein expression, as well as MDR1 and protein expression and improved the drug sensitivity in OV1228/DDP and OV1228/Taxol cells. Conclusion: These results indicated that decreasing $PKC-{\alpha}$ expression with siRNA might be an effective method to improve drug sensitivity in drug resistant cells with elevated levels of $PKC-{\alpha}$ and MDR1. A new siRNA-based therapeutic strategy targeting $PKC-{\alpha}$ gene could be designed to overcome the chemoresistance of ovarian cancer.

Irregular Bone Defect Repair Using Tissue-Engineered Periosteum in a Rabbit Model

Zhao Lin,Zhao Junli,Yu Jia-Jia,Zhang Cangyu 한국조직공학과 재생의학회 2020 조직공학과 재생의학 Vol.17 No.5

Background: In previous studies, we succeeded in repairing a long bone defect with tissue-engineered periosteum (TEP), fabricated by incorporating rabbit mesenchymal stem cells with small intestinal submucosa. In this study, we investigated the feasibility of allogeneic irregular bone defect repair using TEP. Methods: We performed a subtotal resection of the scapula in 36 rabbits to establish a large irregular bone defect model. The rabbits were then randomly divided into three groups (n = 12 per group) and the defects were treated with TEP (Group 1), allogeneic deproteinized bone (DPB) (Group 2) or a hybrid of TEP and DPB (Group 3). At 4, 8, and 12 weeks after surgery, the rabbits were sacrificed, and the implants were harvested. X-ray radiographic and histological examinations were performed to detect bone healing. Ink-formaldehyde perfusion was introduced to qualitatively analyze vascularization in TEP engineered new bone. Results: The repair of scapular defects was diverse in all groups, shown by radiographic and histological tests. The radiographic scores in Group 1 and Group 3 were significantly higher than Group 2 at 8 and 12 weeks (p < 0.05). Histological scores further proved that Group 1 had significantly greater new bone formation compared to Group 3 (p < 0.05), while Group 2 had the lowest osteogenesis at all time-points (p < 0.001). Ink-formaldehyde perfusion revealed aboundant microvessels in TEP engineered new bone. Conclusion: We conclude that TEP is promising for the repair of large irregular bone defects. As a 3D scaffold, DPB could provide mechanical support and a shaping guide when combined with TEP. TEP engineered new bone has aboundant microvessels.

The Existence of a Putative Regulatory Element in 3'-UntranslatedRegion of Proto-oncogene HOX11’s mRNA

Zhao-Zhao Jiang,Wei-Jun Ma,Joseph JY Sung,Yue Li,Hai-Xu Chen,Wai-Keung Leung 한국생화학분자생물학회 2005 BMB Reports Vol.38 No.4

Optimization of Reference Genes for Normalization of the Quantitative Polymerase Chain Reaction in Tissue Samples of Gastric Cancer

Zhao, Lian-Mei,Zheng, Zhao-Xu,Zhao, Xiwa,Shi, Juan,Bi, Jian-Jun,Pei, Wei,Feng, Qiang Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.14

For an exact comparison of mRNA transcription in different samples or tissues with real time quantitative reverse transcription-polymerase chain reaction (qRT-PCR), it is crucial to select a suitable internal reference gene. Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and beta-actin (ACTB) have been frequently considered as house-keeping genes to normalize for changes in specific gene expression. However, it has been reported that these genes are unsuitable references in some cases, because their transcription is significantly variable under particular experimental conditions and among tissues. The present study was aimed to investigate which reference genes are most suitable for the study of gastric cancer tissues using qRT-PCR. 50 pairs of gastric cancer and corresponding peritumoral tissues were obtained from patients with gastric cancer. Absolute qRT-PCR was employed to detect the expression of GAPDH, ACTB, RPII and 18sRNA in the gastric cancer samples. Comparing gastric cancer with corresponding peritumoral tissues, GAPDH, ACTB and RPII were obviously upregulated 6.49, 5.0 and 3.68 fold, respectively. Yet 18sRNA had no obvious expression change in gastric cancer tissues and the corresponding peritumoral tissues. The expression of GAPDH, ${\beta}$-actin, RPII and 18sRNA showed no obvious changes in normal gastric epithelial cells compared with gastric cancer cell lines. The carcinoembryonic antigen (CEA), a widely used clinical tumor marker, was used as a validation gene. Only when 18sRNA was used as the normalizing gene was CEA obviously elevated in gastric cancer tissues compared with peritumoral tissues. Our data show that 18sRNA is stably expressed in gastric cancer samples and corresponding peritumoral tissues. These observations confirm that there is no universal reference gene and underline the importance of specific optimization of potential reference genes for any experimental condition.

Enhanced D-ribose production by genetic modification and medium optimization in Bacillus subtilis 168

Chen Zhao,Xiang-Ying Zhao,Jian-Jun Liu,Jun-Jiao Zhang,Jia-Xiang Zhang,Li-He Zhang 한국화학공학회 2018 Korean Journal of Chemical Engineering Vol.35 No.5

D-ribose, a five-carbon sugar with diverse applications, is mainly produced by transketolase (tkt)-deficient Bacillus subtilis (B. Subtilis). We constructed B.subtilis SFR-3A by replacing the corresponding sites of B. subtilis 168 with the mutation site of tkt in the “wild” D-ribose high-producing strain B. subtilis SFR-4, resulting in 5.29 g/L of Dribose. In the meantime, B.subtilis SFR-159 was constructed by completely removing the tkt gene of B. subtilis 168 with a higher production of 6.21 g/L. Through medium optimization, batch fermentation of SFR-3A and SFR-159 gave the best result of 27.56 g/L and 29.89 g/L, which corresponds to productivity of 0.51 g/L/h and 0.41 g/L/h, respectively. In this work, SFR-3A showed more latent capacity over SFR-159 as to productivity and had greater potential to serve as a platform for D-ribose production.

Metastasis associated genomic aberrations in stage II rectal cancer

Hong Zhao,Zhi-Zhou Shi,Rui Jiang,Dong-Bing Zhao,Hai-Tao Zhou,Jian-Wei Liang,Xin-Yu Bi,Jian-Jun Zhao,Zhi-Yu Li,Jian-Guo Zhou,Zhen Huang,Ye-Fan Zhang,Jian Wang,Xin Xu,Yan Cai,Ming-Rong Wang,Yu Zhang 한국유전학회 2016 Genes & Genomics Vol.38 No.11

Genomic aberrations of rectal carcinoma, especially DNA copy number changes associated with metastasis were largely unclear. We aim to identify the metastasis associated biomarkers in stage II rectal cancer. Formalin-fixed, paraffin-embedded primary tumor tissues of stage II rectal carcinoma were analyzed by array-based comparative genomic hybridization, and genomic aberrations were identified by Genomic Workbench and SAM software. Copy number changes and mRNA expressions were validated by Real-time PCR in an independent rectal cancer samples. The results showed that the most frequent gains in stage II rectal cancer were at 1q21.2-q23.1, 3p21.31, 11q12.2-q23.3, 12q24.11-q24.31, 12q13.11-q14.1 and losses in 18q11.2-q23, 17q21.33-q22, 13q31.1-q31.3, 21q21.1-q21.3, 8p23.3-p23.1 and 4q22.1-q23. Twenty-two amplifications and five homozygous deletions were also identified. We further found that S100A1 (1q21.3-q23.1), MCM7 (7q22.1) and JUND (19p13.11) were amplified and overexpressed in stage II rectal cancer. Interestingly, the genomic aberrations affected 14 signaling pathways including VEGF signaling pathway and fatty acid metabolism. Most importantly, loss of 13q31.1-q34 and gain of 1q44 were associated with distant metastasis. Our results indicated that these metastasis associated genomic changes may be useful to reveal the pathogenesis of rectal cancer metastasis and identify candidate biomarkers.

Mechanistic Analysis of Taxol-induced Multidrug Resistance in an Ovarian Cancer Cell Line

Wang, Ning-Ning,Zhao, Li-Jun,Wu, Li-Nan,He, Ming-Feng,Qu, Jun-Wei,Zhao, Yi-Bing,Zhao, Wan-Zhou,Li, Jie-Shou,Wang, Jin-Hua Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.9

Objectives: To establish a taxol-resistant cell line of human ovarian carcinoma (A2780/Taxol) and investigate its biological features. Methods: The drug-resistant cell line (A2780/Taxol) was established by continuous stepwise selection with increasing concentrations of Taxol. Cell morphology was assessed by microscopy and growth curves were generated with in vitro and in vivo tumor xenograft models. With rhodamine123 (Rh123) assays, cell cycle distribution and the apoptotic rate were analyzed by flow cytometry (FCM). Drug resistance-related and signal associated proteins, including P-gp, MRPs, caveolin-1, PKC-${\alpha}$, Akt, ERK1/2, were detected by Western blotting. Results: A2780/Taxol cells were established with stable resistance to taxol. The drug resistance index (RI) was 430.7. Cross-resistance to other drugs was also shown, but there was no significant change to radioresistance. Compared with parental cells, A2780/Taxol cells were significantly heteromorphous, with a significant delay in population doubling time and reduced uptake of Rh123 (p<0.01). In vivo, tumor take by A2780 cells was 80%, and tumor volume increased gradually. In contrast, with A2780/Taxol cells in xenograft models there was no tumor development. FCM analysis revealed that A2780/Taxol cells had a higher percentage of G0/G1 and lower S phase, but no changes of G2 phase and the apoptosis rate. Expression of P-gp, MRP1, MRP2, BCRP, LRP, caveolin-1, PKC-${\alpha}$, Phospho-ERK1/2 and Phospho-JNK protein was significantly up-regulated, while Akt and p38 MARK protein expression was not changed in A2780/Taxol cells. Conclusion: The A2780/Taxol cell line is an ideal model to investigate the mechanism of muti-drug resistance related to overexpression of drug-resistance associated proteins and activation of the PKC-${\alpha}/ERK$ (JNK) signaling pathway.

Targeted Editing of Myostatin Gene in Sheep by Transcription Activator-like Effector Nucleases

Zhao, Xinxia,Ni, Wei,Chen, Chuangfu,Sai, Wujiafu,Qiao, Jun,Sheng, Jingliang,Zhang, Hui,Li, Guozhong,Wang, Dawei,Hu, Shengwei Asian Australasian Association of Animal Productio 2016 Animal Bioscience Vol.29 No.3

Myostatin (MSTN) is a secreted growth factor expressed in skeletal muscle and adipose tissue that negatively regulates skeletal muscle mass. Gene knockout of MSTN can result in increasing muscle mass in sheep. The objectives were to investigate whether myostatin gene can be edited in sheep by transcription activator-like effector nucleases (TALENs) in tandem with single-stranded DNA oligonucleotides (ssODNs). We designed a pair of TALENs to target a highly conserved sequence in the coding region of the sheep MSTN gene. The activity of the TALENs was verified by using luciferase single-strand annealing reporter assay in HEK 293T cell line. Co-transfection of TALENs and ssODNs oligonucleotides induced precise gene editing of myostatin gene in sheep primary fibroblasts. MSTN gene-edited cells were successfully used as nuclear donors for generating cloned embryos. TALENs combined with ssDNA oligonucleotides provide a useful approach for precise gene modification in livestock animals.

Analysis of deliverability data in shale gas reservoirs: pseudo-pressure and pressure employed

Zhao, Chaojie,Li, Jun,Zhang, Hui 한국자원공학회 2019 Geosystem engineering Vol.22 No.4

Forecasting deliverability in shale gas reservoirs accurately has received much attention in the industry in recent years. Most wells in shale gas reservoirs are horizontal with multiple fractures, and it has been widely recognized that the dominant early flow regime is usually long-duration transient flow. The most popular method for analyzing linear flow is the plot of rate-normalized pressure versus square root of time, where the pseudo-pressure is employed for gas. However, the pseudo-pressure employed approach is difficult to handle by hand than the pressure employed approach. The purpose of this work is to evaluate the accuracy of pseudo-pressure employed method for analyzing gas rate in shale gas reservoirs, and establish which method is the most simple and accurate for reserve estimation. Based on a number of numerically simulated cases, comparisons between the pseudo-pressure and pressure employed methods for estimating gas rate are made. It is shown that the pressure employed method yields the gas rate that not quite accurately match the simulated values, however, as the same general parameters, the pseudo-pressure employed method really does not improve this inaccuracy. Accordingly, the pressure employed approach is a good and simple method for forecasting gas rate. In addition, depending on the simple hand method, a modification approach is proposed by incorporating constant factors to forecast the gas rate with more confidence. This work will provide an efficient guidance to assist analysts in evaluating hydrocarbon deliverability rapidly and efficiently in shale gas reservoirs.