Effect of Annealing Atmosphere on Photoluminescence and Gas Sensing of Solution-Combustion-Synthesized Al, Pd Co-Doped ZnO Nanoparticles

Yan Li,Min Liu,Tan Lv,Qiong Wang,Yun-ling Zou,Xiao-xue Lian,Hong-peng Liu 대한금속·재료학회 2015 ELECTRONIC MATERIALS LETTERS Vol.11 No.6

Al, Pd co-doped ZnO nanoparticles (NPs) synthesized using a solution combustion method and subsequent annealing process under various atmospheres, including air, nitrogen, and hydrogen, were characterized using x-ray diffraction, energy-dispersive x-ray spectroscopy, fieldemission scanning electron microscopy, transmission electron microscopy, and photoluminescence spectroscopy. The gas-sensing properties of the sensors based on the NPs were also examined. The results indicated that the Al, Pd co-doped ZnO NPs, with an average crystallite size of 10 nm, exhibited enhanced gas-sensing performance compared with that of pure ZnO and Al-doped ZnO. The response of the Al, Pd co-doped ZnO NPs annealed in N2 to ethanol (49.22) was nearly 5.7 times higher than that to acetone (8.61) and approximately 20 - 27 times higher than that to benzene (2.38), carbon monoxide (2.23), and methane (1.78), which demonstrates their excellent selectivity to ethanol versus other gases. This high ethanol response can be attributed to the combined effects of the small size, Schottky barrier, lattice defects, and catalysis.

Research on the Method of Fault Diagnosis Based on Multiple Classifiers Fusion

Yan Wen,Jiwen Tan,Hong Zhan,Hao Wang 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.2

In traditional fault diagnosis method, a large number of experiments are needed to get the optimal performance classifier which diagnoses type of fault. Because of classifier algorithm limit, there is no one classifier can be applied to all kinds of fault diagnosis. In order to avoid the disadvantages caused by single classifier approach, decision level fusion method based on multiple classifiers fusion is introduced in the field of fault diagnosis. The fusion method with fuzzy comprehensive evaluation is put forward and the basic evaluation model is set up. The reasonable distribution of classifiers weight that affects diagnosis result directly is vital. Firstly, the evaluation function which measures member classifier’s diagnostic accuracy and correctness is constructed based on the theory of information entropy. Then, weights are distributed to each classifier with entropy coefficient according to the value of evaluation function. Experiments are carried out to demonstrate the effectiveness of the proposed method and results show that fault recognition rate after fusion is higher compared with the single classifier method.

Analysis of Free Amino Acids during Fermentation by Bacillus subtilis Using Capillary Electrophoresis

Yanli Ren,Jinyan Zhou,Xiaoyong Zhang,Zhidong Li,Juan Zhong,Jie Yang,Tan Xu,Hong Tan 한국생물공학회 2012 Biotechnology and Bioprocess Engineering Vol.17 No.6

A high performance capillary electrophoresis (HPCE) method was presented to identify and quantitate free amino acids during fermentation by Bacillus subtilis. Amino acids, pre-column derivatized with phenylisothicyanate,were separated and characterized by HPCE. In order to optimize separation conditions, the assay was developed by varying the β-cyclodextrin concentration and pH of the background electrolyte. A buffer system comprising 30 mM phosphate and 3 mM β-cyclodextrin at pH 7.0, voltage of 20 kV and detection wavelength of 254 nm showed the best results, with 17 out of 20phenylthioncarbamyl amino acids in a solution adequately separated. For quantification, p-aminobenzoic acid was added as an internal standard. Analysis of free amino acids in Bacillus subtilis culture medium using this method revealed good consistency with the values obtained using conventional ninhydrin-based amino acid analyzer. Four free amino acids (aspartic acid, glutamic acid, proline, and tyrosine) concentration in an extracellular matrix during fermentation by Bacillus subtilis were mainly monitored using this method.

Increasing Demeclocycline Production in Streptomyces aureofaciens by Manipulating the Expression of a Novel SARP Family Regulator and Its Genes

Yan-Ying Tan,Guang-Yao Zhu,Rui-Fang Ye,Hong-Zhou Zhang,De-Yu Zhu 한국생물공학회 2021 Biotechnology and Bioprocess Engineering Vol.26 No.6

Demeclocycline (DMCTC), a tetracycline derivative antibiotic produced by Streptomyces aureofaciens, has attracted attention owing to its high bioavailability, prolonged maintenance of a therapeutic concentration, and greater efficacy against many infectious microorganisms. However, the productivity of the DMCTC-producing strains has remained low. Thus, it is necessary to identify gene-knockout or amplification targets to increase DMCTC production. Here, we demonstrated that ctcB, which encodes a Streptomyces antibiotic regulatory protein (SARP), and ctcC, which encodes a resistance gene, positively regulate the biosynthesis of DMCTC in S. aureofaciens strain DT1. In particular, overexpression of the ctcB gene in S. aureofaciens DT1 significantly enhanced DMCTC production, resulting in increased expression of ctcG, ctcN, ctcQ, ctcH, ctcV, and ctcC. The deletion of ctcB dramatically reduced the DMCTC level, implying that CtcB is an activator of DMCTC biosynthesis. Although overexpression of the ctcC, which encodes a ribosomal protection protein, enhancing DMCTC biosynthesis in S. aureofaciens DT1, the improvement was limited compared with that achieved by ctcB overexpression. This is the first study to identify the role of ctcB and ctcC in DMCTC accumulation; these genes may also be ideal candidate targets for facilitating DMCTC production by other Streptomyces strains.

Fault Diagnosis Model Based on Multi-level Information Fusion for CNC Machine Tools

Wen Yan,Tan Ji-wen,Zhan Hong,Sun Xian-bin 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.8

The difficulty of CNC machine tools fault diagnosis is bigger than other general equipments because of the complex structure and the coupling among subsystems. The fault diagnosis model based on multi-level information fusion and hybrid intelligence is studied to improve reliability of fault diagnosis. Information from built-in sensors is used to monitor the status of CNC machine tools. The diagnosis principles of internal parameters-motor current, torque, temperature and following error are analyzed. Internal information and external sensors are two main sources which provide data to diagnosis. In order to detect effective fault signal, features of time domain, frequency domain and time-frequency domain are extracted. All these features constitute the feature set. The features are selected by the method of Kernel Principal Component Analysis (KCPA). Then the sensitive feature set is obtained. The method of multiple classifier fusion based on fuzzy comprehensive evaluation is researched. The determination method of weight based on information entropy is proposed. This diagnosis model has been tested feed system mechanical fault diagnosis of CNC machine tools and the results show which is effective and versatile.

Carbon-Ion-Implanted Nd, MgO-Codoped Near-Stoichiometric Lithium-Niobate Optical Waveguides

Ning-Ning Dong,Yang Tan,Yan-Xia Kong,Feng Chen,Hong-Ji Ma 한국물리학회 2009 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.55 No.6

Nd, MgO codoped near stoichiometric lithium niobate (Nd:MgO:SLN) is a promising laser gain crystal for infrared laser generations. We report on, to our knowledge for the first time, the planar waveguide formation in Nd:MgO:SLN crystal by MeV carbon ion implantation at dose of 1014 ions/cm2. The guiding properties are investigated by using the well-known m-line technique and end-face arrangement. The refractive index profiles of the waveguides show a typical “well + barrier” distribution, which could confine the light propagation in a non-leaky way. In addition, a numerical simulation of the light propagation shows that the waveguide modal distributions are in good agreement with the experimental data, which means potential applications for the formation of designable devices in Nd:MgO:SLN by using carbon ion implantation. Nd, MgO codoped near stoichiometric lithium niobate (Nd:MgO:SLN) is a promising laser gain crystal for infrared laser generations. We report on, to our knowledge for the first time, the planar waveguide formation in Nd:MgO:SLN crystal by MeV carbon ion implantation at dose of 1014 ions/cm2. The guiding properties are investigated by using the well-known m-line technique and end-face arrangement. The refractive index profiles of the waveguides show a typical “well + barrier” distribution, which could confine the light propagation in a non-leaky way. In addition, a numerical simulation of the light propagation shows that the waveguide modal distributions are in good agreement with the experimental data, which means potential applications for the formation of designable devices in Nd:MgO:SLN by using carbon ion implantation.

Methylenetetrahydrofolate Reductase Polymorphisms and Susceptibility to Esophageal Cancer in Chinese Populations: a Meta-analysis

Yang, Yong-Bin,Shang, Yan-Hong,Tan, Yan-Li,Kang, Xian-Jiang,Meng, Ming,Zhao, Zhan-Xue Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.3

Although many epidemiologic studies investigated the methylenetetrahydrofolate reductase (MTHFR) polymorphisms and their associations with esophageal cancer, definite conclusions could not be drawn. To clarify the effects of MTHFR polymorphisms on the risk of esophageal cancer, a meta-analysis was here performed in Chinese populations. A total of 16 studies including 3,040 cases and 4,127 controls were involved in this metaanalysis. Overall, significant associations were found between the MTHFR C677T polymorphism and esophageal cancer risk when all studies in Chinese populations were pooled into the meta-analysis (T vs. C, OR = 1.19, 95% CI = 1.06-1.34; TT vs. CC, OR = 1.35, 95% CI = 1.07-1.70; TT+ CT vs. CC, OR = 1.29, 95% CI = 1.08-1.54; TT vs. CC + CT, OR = 1.19, 95% CI = 1.03-1.37). In subgroup analyses stratified by ethnicity and source of controls, the same results were found in Kazakh (TT vs. CC, OR = 1.38, 95% CI = 1.02-1.87; TT + CT vs. CC, OR = 1.50, 95% CI = 1.03-2.18), in not stated populations (T vs. C, OR = 1.24, 95% CI = 1.08-1.42; TT vs. CC, OR = 1.47, 95% CI = 1.10-1.96; TT + CT vs. CC, OR = 1.30, 95% CI = 1.05-1.60; TT vs. CC + CT, OR = 1.32, 95% CI = 1.12-1.56), and in hospital-based studies (T vs. C, OR = 1.34, 95% CI = 1.19-1.51; TT vs. CC, OR = 1.81, 95% CI = 1.37-2.39; TT + CT vs. CC, OR = 1.51, 95% CI = 1.26-1.83; and TT vs. CC + CT, OR = 1.39, 95% CI = 1.13-1.70). In conclusion, this meta-analysis provides evidence that the MTHFR C677T polymorphism contributes to esophageal cancer development in Chinese populations.

The Prognostic Value of Treatment-Related Lymphopenia in Nasopharyngeal Carcinoma Patients

Li-Ting Liu,Qiu-Yan Chen,Lin-Quan Tang,Shan-Shan Guo,Ling Guo,Hao-Yuan Mo,Ming-Yuan Chen,Chong Zhao,Xiang Guo,Chao-Nan Qian,Mu-Sheng Zeng,Jin-Xin Bei,Jing Tan,Shuai Chen,Ming-Huang Hong,Jian-Yong Shao 대한암학회 2018 Cancer Research and Treatment Vol.50 No.1

Purpose This study was conducted to evaluate the prognostic value of treatment-related lymphopenia in patients with nasopharyngeal carcinoma (NPC). Materials and Methods A total of 413 consecutive stage II-IVb NPC patients treated with concurrent chemoradiotherapy (CCRT) were enrolled. The overall survival (OS), progression-free survival (PFS), and distant metastasis-free survival (DMFS) were calculated with the Kaplan-Meier method, and differences were compared using the log-rank test. Results A minimum (mini)–absolute lymphocyte counts (ALC) of < 390 cells/μL or ALC after 3 months of CCRT (post3m-ALC) < 705 cells/μL was significantly associated with worse outcome than mini-ALC ! 390 cells/μL (OS, p=0.002; PFS, p=0.005; DMFS, p=0.004) or post3m-ALC ! 705 cells/μL (OS, p < 0.001; PFS, p < 0.001; DMFS, p=0.001). Patients with lymphopenia (mini-ALC < 390 cells/μL and post3m-ALC < 705 cells/μL) had a worse prognosis than those without lymphopenia (mini-ALC ! 390 cells/μL and post3m-ALC ! 705 cells/μL) (OS, p < 0.001; PFS, p < 0.001; DMFS, p < 0.001). Multivariate analysis revealed that post3m-ALC was an independent prognostic factor for OS (hazard ratio [HR], 1.76; 95% confidence interval [CI], 1.12 to 2.78; p=0.015), PFS (HR, 1.86; 95% CI, 1.23 to 2.82; p=0.003), and DMFS (HR, 1.87; 95% CI, 1.13 to 3.08; p=0.014). Multivariate analysis also revealed that patients with lymphopenia had a high risk of death (HR, 3.79; 95% CI, 1.75 to 8.19; p=0.001), disease progression (HR, 2.93; 95% CI, 1.59 to 5.41; p=0.001), and distant metastasis (HR, 3.89; 95% CI, 1.67 to 9.10; p=0.002). Multivariate analysis performed with time dependent Cox regression demonstrated ALC was an independent prognostic factor for OS (HR, 0.995; 95% CI, 0.991 to 0.999; p=0.025) and PFS (HR, 0.993; 95% CI, 0.988 to 0.998; p=0.006). Conclusion Treatment-related lymphopenia was a poor prognostic factor in NPC patients.

Transcriptome sequencing discovers genes related to fatty acid biosynthesis in the seeds of Eucommia ulmoides

Fang-dong Li,Yan-zhi Feng,Lu Wang,Jian-min Fu,Ta-na Wuyun,Hong-yan Du,Xiao-feng Tan,Feng Zou 한국유전학회 2016 Genes & Genomics Vol.38 No.3

Eucommia ulmoides is a focus of considerable attention because it is used to produce gutta-percha latex and raw materials for traditional Chinese medicine. The species has also been widely planted for vegetable oil production due to the high content of alpha-linolenic acid (ALA) in the seeds. However, little was known about fatty acid biosynthesis in the seeds. Here, we present transcriptome analyses that identified genes related to the fatty acid biosynthesis pathways in the seeds collected 70 and 160 days after flowering (DAF) from two varieties: ‘Huazhong No. 6’ (ALA content of 38.7 %) and ‘Huazhong No. 10’ (ALA content of 67.6 %). De novo assembly generated 96,469 unigenes with an average length of 690 bp. Among them, 11,260 unigenes identified by functional annotation against the Kyoto Encyclopedia of Genes and Genomes database were mapped to 117 metabolic pathways. 65 unigenes involved in fatty acid biosynthesis include 5 coding for 3-oxoacyl-ACP reductase, 2 coding for b-hydroxyacyl-ACP dehydratase, 10 coding for b-ketoacyl-ACP synthase II, and 2 coding for enoyl-ACP reductase I. Expression of the nine differentially expressed unigenes coding for major enzymes in fatty acid biosynthesis was validated by real-time fluorescent quantitative PCR (qPCR) using RNA from six seed stages (70, 88, 106, 124, 142, and 160 DAF) in ‘Huazhong No. 10’. The qPCR analysis showed that expression of these 9 unigenes all changed significantly at 88 DAF. This study provides a large-scale transcriptome annotation of E. ulmoides, which is fundamental information for further characterizing gene functionals involved in the process of seed development.

Optimal Conditions for Hepatitis B Core Antigen Production in Shaked Flask Fermentation

Beng Ti Tey,Tau Chuan Ling,Yan Peng Tan,Swee Tin Ong,Arbakariya Ariff,Wen Siang Tan,Hong Puay Ong,Kok Hoe Yong 한국생물공학회 2004 Biotechnology and Bioprocess Engineering Vol.9 No.5

The effects of various environmental factors such as pH (5, 6, 7, 8 and 9), temperature (30, 37 and 40C) and rotational speed (150, 200 and 250 rpm) on the growth and the hepatitis B core antigen (HBcAg) production of Escherichia coli W3110IQ were examined in the present study. The highest growth rate is achieved at pH 7, 37C and at a rotational speed of 250 rpm which is 0.927 h-1. The effect of pH on cell growth is more substantial compared to other parameters; it recorded a 123% different between the highest growth rate (0.927 h-1) at pH 7 and lowest growth at pH 5. The highest protein yield is achieved at pH 9, rotational speed of 250 rpm and 40C. The yield of protein at pH 7 is 154% higher compared to the lowest yield achieved at pH 5. There is about 28% different of the protein yield for the E. coli cultivated at 250 rpm compared to that at 150 rpm which has the lowest HBcAg yield. The yield of protein at 40C is 38% higher compared to the lowest yield achieved at 30C.