The effects of codon usage on the formation of secondary structures of nucleocapsid protein of peste des petits ruminants virus

Xiao‑xia Ma,Yi‑ning Wang,Xiao‑an Cao,Xue‑rui Li,Yong‑sheng Liu,Jian‑hua Zhou,Xue‑peng Cai 한국유전학회 2018 Genes & Genomics Vol.40 No.9

The nucleocapsid (N) protein of peste des petits ruminants virus (PPRV) with a conserved amino acid usage pattern plays an important role in viral replication. The primary objective of this study was to estimate roles of synonymous codon usages of PPRV N gene and tRNA abundances of host in the formation of secondary structure of N protein. The potential effects of synonymous codon usages of N gene and tRNA abundances of host on shaping different folding units (α-helix, β-strand and the coil) in N protein were estimated, based on the information about the modeling secondary structure of PPRV N protein. The synonymous codon usage bias was found in different folding units in PPRV N protein. To better understand the role of translation speed caused by variant tRNA abundances in shaping the specific folding unit in N protein, we modeled the changing trends of tRNA abundance at the transition boundaries from one folding unit to another folding unit (β-strand → coil, coil → β-strand, α-helix → coil, coil → α-helix). The obvious fluctuations of tRNA abundance were identified at the two transition boundaries (β-strand → coil and coil → β-strand) in PPRV N protein. Our findings suggested that viral synonymous codon usage bias and cellular tRNA abundance variation might have potential effects on the formation of secondary structure of PPRV N protein.

Clinical Study on Fluvoxamine Combined with Oxycodone Prolonged-Release Tablets in Treating Patients with Moderate to Severe Cancer Pain

Xiao, Yang,Liu, Jun,Huang, Xin-En,Ca, Li-Hua,Ma, Yi-Min,Wei, Wei,Zhang, Rong-Xia,Huang, Xiao-Hong,Chang, Juan,Wu, Yi-Jia Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.23

Objective: To observe treatment effects and safety of fluvoxamine combined with oxycodone prolonged-release tablets in treating patients with moderate to severe cancer pain. Methods: Patients confirmed pathologically with cancer and complicated with moderate to severe pain, were divided into control and experimental groups. Oxycodone prolonged-release tablets, with or without fluvoxamine, were administrated to all study patients until pain relief. Degree of pain relief, dose of oxycodone prolonged-release tablets, side effects and quality of life were compared before and after treatment. Results: In total, 120 patients were recruited. No statistically significant difference was detected regarding age, gender, types of cancer, KPS between two groups of patients (P>0.05). Baseline pain score of patients with moderate pain in treatment and control group was $4.9{\pm}0.8$ and $5.1{\pm}0.8$, respectively; and decreased to $1.8{\pm}1.1$ and $1.2{\pm}1.1$ after treatment, respectively. Pain intensity was significantly reduced in the treatment group (P=0.028). Average daily consumption of oxycodone prolonged-release tablets was ($54.0{\pm}19.6$) mg and ($44.7{\pm}18.7$) mg respectively, which is lower in treatment grpup than in control group, but the difference was not statistically significant (P=0.065). Baseline pain score of patients with severe pain in treatment and control groups were $8.3{\pm}1.1$ and $8.3{\pm}1.1$, respectively; and pain intensity after treatment decreased to $2.9{\pm}1.0$ and $2.3{\pm}1.0$. Pain intensity was significantly reduced in the treatment group, with statistical significance (P=0.026). Average daily consumption of oxycodone prolonged-release tablets was ($132.0{\pm}42.2$) mg and ($110.7{\pm}33.9$) mg, respectively, which is lower in treatment group than in control group, and the difference was statistically significant (P=0.035). In terms of quality of life, patients in treatment group had better performance status, daily activity, mood, and sleep than that in control group (P < 0.05). Patients in two groups had similar side effects, eg., constipation, nausea/vomiting, lethargy, dizziness, itchy skin, dysuria, and ataxia. Lower incidence of nausea/vomiting, lethargy, was obtained from patients in treatment than in control group, while significant low constipation was observed in treatment than in control group (35.0% vs 49.2%, P=0.026). Conclusion: Fluvoxamine combined with oxycodone prolonged-release tablets could be more effective in treating patients with cancer pain, and could reduce the dosage of oxycodone prolonged-release tablets and thus be associated with lower side effects, and improved quality of life.

Different Catabolism Pathways Triggered by Various Methylxanthines in Caffeine-Tolerant Bacterium Pseudomonas putida CT25 Isolated from Tea Garden Soil

( Yi-xiao Ma ),( Xiao-han Wu ),( Hui-shi Wu ),( Zhan-bo Dong ),( Jian-hui Ye ),( Xin-qiang Zheng ),( Yue-rong Liang ),( Jian-liang Lu ) 한국미생물생명공학회(구 한국산업미생물학회) 2018 Journal of microbiology and biotechnology Vol.28 No.7

The degradation efficiency and catabolism pathways of the different methylxanthines (MXs) in isolated caffeine-tolerant strain Pseudomonas putida CT25 were comprehensively studied. The results showed that the degradation efficiency of various MXs varied with the number and position of the methyl groups on the molecule (i.e., xanthine > 7-methylxanthine ≈ theobromine > caffeine > theophylline > 1-methylxanthine). Multiple MX catabolism pathways coexisted in strain CT25, and a different pathway would be triggered by various MXs. Demethylation dominated in the degradation of N-7-methylated MXs (such as 7- methylxanthine, theobromine, and caffeine), where C-8 oxidation was the major pathway in the catabolism of 1-methylxanthine, whereas demethylation and C-8 oxidation are likely both involved in the degradation of theophylline. Enzymes responsible for MX degradation were located inside the cell. Both cell culture and cell-free enzyme assays revealed that N-1 demethylation might be a rate-limiting step for the catabolism of the MXs. Surprisingly, accumulation of uric acid was observed in a cell-free reaction system, which might be attributed to the lack of activity of uricase, a cytochrome c-coupled membrane integral enzyme.

Effects of Oxygen Content on the Simultaneous Microbial Removal of SO2 and NOx in Biotrickling Towers

Xing Chun Wang,Xiao Yi Bi,Pei Shi Sun,Jin Quan Chen,Ping Zou,Xiao Ming Ma,Jing Zhang,Hai Yu Wang,Xiao Yi Xu 한국생물공학회 2015 Biotechnology and Bioprocess Engineering Vol.20 No.5

This study uses microbial methods to research the influence of oxygen (O2) content on the removal efficiency of sulfur dioxide (SO2) and nitrogen oxides (NOx) in a tandem twin-towers desulfurization and denitrification process system. Oxygen can play a significant role in biotrickling towers. Other important factors had already been optimized prior to the study, including inlet concentration, gas flow rate, and temperature. SO2 and NOx were prepared by a chemical method. A gas flow meter was used to regulate nitrogen (N2) that had been stored in steel cylinders. In this way, the O2 content was adjusted in the biotrickling towers by controlling the N2 flow rate. Five gradients of O2 content were selected for investigation, namely 4, 8, 12, 16, and 20%. Results indicated that the SO2 removal efficiency from mixed gas (SO2 and NOx) can reach 100%, from all of the five O2 gradients, in biotrickling towers. In a tandem twin-towers desulfurization and denitrification process system, the NOx removal efficiency and the inlet concentration of nitrogen dioxide (NO2) gradually increased as the O2 content increased. Specifically, the average removal efficiency of NOx increased from 49.28 to 80.85% as the O2 content changed from 4 to 20%. The oxygen levels influenced the removal of NOx but the SO2 removal efficiency in mixed gas was always stable.

Covalent Immobilization of Penicillin G Acylase onto Fe₃O₄@Chitosan Magnetic Nanoparticles

( Xiao Min Ling ),( Xiang Yu Wang ),( Ping Ma ),( Yi Yang ),( Jie Mei Qin ),( Xue Jun Zhang ),( Ye Wang Zhang ) 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.5

Penicillin G acylase (PGA) was immobilized on magnetic Fe₃O₄@chitosan nanoparticles through the Schiff base reaction. The immobilization conditions were optimized as follows: enzyme/support 8.8 mg/g, pH 6.0, time 40 min, and temperature 25℃. Under these conditions, a high immobilization efficiency of 75% and a protein loading of 6.2 mg/g-support were obtained. Broader working pH and higher thermostability were achieved by the immobilization. In addition, the immobilized PGA retained 75% initial activity after ten cycles. Kinetic parameters Vmax and Km of the free and immobilized PGAs were determined as 0.113 mmol/min/mg-protein and 0.059 mmol/min/mg-protein, and 0.68 mM and 1.19 mM, respectively. Synthesis of amoxicillin with the immobilized PGA was carried out in 40% ethylene glycol at 25℃ and a conversion of 72% was obtained. These results showed that the immobilization of PGA onto magnetic chitosan nanoparticles is an efficient and simple way for preparation of stable PGA.

First-principles study of transport properties of endohedral Li@C20 metallofullerene

Yi-Peng An,Chuan-Lu Yang,Mei-Shan Wang,Xiao-Guang Ma,De-Hua Wang 한국물리학회 2010 Current Applied Physics Vol.10 No.1

The transport properties of the endohedral Li@C20 metallofullerene are studied using density functional non-equilibrium Green’s function method. The equilibrium conductance of Li@C20 metallofullerene becomes larger than that of the empty C20 fullerene molecule. The I.V curve under low-bias voltage shows the characteristic of metallic behavior; another, the novel negative differential resistance behavior is also observed. It is found that the doping effect of Li atom significantly changes the transport properties of C20 fullerene.

Intravoxel Incoherent Motion Magnetic Resonance Imaging for Assessing Parotid Gland Tumors: Correlation and Comparison with Arterial Spin Labeling Imaging

Ma Gao,Xu Xiao-Quan,Zhu Liu-Ning,Jiang Jia-Suo,Su Guo-Yi,Hu Hao,Bu Shou-Shan,Wu Fei-Yun 대한영상의학회 2021 Korean Journal of Radiology Vol.22 No.2

Objective: To compare and correlate the findings of intravoxel incoherent motion (IVIM) magnetic resonance (MR) imaging and arterial spin labeling (ASL) imaging in characterizing parotid gland tumors. Materials and Methods: We retrospectively reviewed 56 patients with parotid gland tumors evaluated by MR imaging. The true diffusion coefficient (D), pseudo-diffusion coefficient (D*), and fraction of perfusion (f) values of IVIM imaging and tumor-to-parotid gland signal intensity ratio (SIR) on ASL imaging were calculated. Spearman rank correlation coefficient, chi-squared, Mann-Whitney U, and Kruskal-Wallis tests with the post-hoc Dunn-Bonferroni method and receiver operating characteristic curve assessments were used for statistical analysis. Results: Malignant parotid gland tumors showed significantly lower D than benign tumors (p = 0.019). Within subgroup analyses, pleomorphic adenomas (PAs) showed significantly higher D than malignant tumors (MTs) and Warthin’s tumors (WTs) (p < 0.001). The D* of WTs was significantly higher than that of PAs (p = 0.031). The f and SIR on ASL imaging of WTs were significantly higher than those of MTs and PAs (p < 0.05). Significantly positive correlation was found between SIR on ASL imaging and f (r = 0.446, p = 0.001). In comparison with f, SIR on ASL imaging showed a higher area under curve (0.853 vs. 0.891) in discriminating MTs from WTs, although the difference was not significant (p = 0.720). Conclusion: IVIM and ASL imaging could help differentiate parotid gland tumors. SIR on ASL imaging showed a significantly positive correlation with f. ASL imaging might hold potential to improve the ability to discriminate MTs from WTs.

Capillarity-Driven Self-Assembly of Silver Nanowires-Coated Fibers for Flexible and Stretchable Conductor

Yi Li,Jun Chen,Xiao Han,Yinghui Li,Ziqiang Zhang,Yanwen Ma 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.12

The rapid development of smart textiles requires the large-scale fabrication of conductive fibers. In this study, we develop a simple, scalable and low-cost capillary-driven self-assembly method to prepare conductive fibers with uniform morphology, high conductivity and good mechanical strength. Fiber-shaped flexible and stretchable conductors are obtained by coating highly conductive and flexible silver nanowires (Ag NWs) on the surfaces of yarn and PDMS fibers through evaporation-induced flow and capillary-driven self-assembly, which is proven by the in situ optical microscopic observation. The density of Ag NWs and linear resistance of the conductive fibers could be regulated by tuning the assembly cycles. A linear resistance of 1.4Ω/cm could be achieved for the Ag NWs-coated nylon, which increases only 8% after 200 bending cycle, demonstrating high flexibility and mechanical stability. The flexible and stretchable conductive fibers have great potential for the application in wearable devices.

Inhibitory Effects of Onion (Allium cepa L.) Extract on Proliferation of Cancer Cells and Adipocytes via Inhibiting Fatty Acid Synthase

Wang, Yi,Tian, Wei-Xi,Ma, Xiao-Feng Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.11

Onions (Allium cepa L.) are widely used in the food industry for its nutritional and aromatic properties. Our studies showed that ethyl acetate extract of onion (EEO) had potent inhibitory effects on animal fatty acid synthase (FAS), and could induce apoptosis in FAS over-expressing human breast cancer MDA-MB-231 cells. Furthermore, this apoptosis was accompanied by reduction of intracellular FAS activity and could be rescued by 25 mM or 50 mM exogenous palmitic acids, the final product of FAS catalyzed synthesis. These results suggest that the apoptosis induced by EEO occurs via inhibition of FAS. We also found that EEO could suppress lipid accumulation during the differentiation of 3T3-L1 adipocytes, which was also related to its inhibition of intracellular FAS activity. Since obesity is closely related to breast cancer and obese patients are at elevated risk of developing various cancers, these findings suggested that onion might be useful for preventing obesity-related malignancy.

Utility of Readout-Segmented Echo-Planar Imaging-Based Diffusion Kurtosis Imaging for Differentiating Malignant from Benign Masses in Head and Neck Region

Gao Ma,Xiao-Quan Xu,Hao Hu,Guo-Yi Su,Jie Shen,Hai-Bin Shi,Fei-Yun Wu 대한영상의학회 2018 Korean Journal of Radiology Vol.19 No.3

Objective: To compare the diagnostic performance of readout-segmented echo-planar imaging (RS-EPI)-based diffusion kurtosis imaging (DKI) and that of diffusion-weighted imaging (DWI) for differentiating malignant from benign masses in head and neck region. Materials and Methods: Between December 2014 and April 2016, we retrospectively enrolled 72 consecutive patients with head and neck masses who had undergone RS-EPI-based DKI scan (b value of 0, 500, 1000, and 1500 s/mm2) for pretreatment evaluation. Imaging data were post-processed by using monoexponential and diffusion kurtosis (DK) model for quantitation of apparent diffusion coefficient (ADC), apparent diffusion for Gaussian distribution (Dapp), and apparent kurtosis coefficient (Kapp). Unpaired t test and Mann-Whitney U test were used to compare differences of quantitative parameters between malignant and benign groups. Receiver operating characteristic curve analyses were performed to determine and compare the diagnostic ability of quantitative parameters in predicting malignancy. Results: Malignant group demonstrated significantly lower ADC (0.754 ± 0.167 vs. 1.222 ± 0.420, p < 0.001) and Dapp (1.029 ± 0.226 vs. 1.640 ± 0.445, p < 0.001) while higher Kapp (1.344 ± 0.309 vs. 0.715 ± 0.249, p < 0.001) than benign group. Using a combination of Dapp and Kapp as diagnostic index, significantly better differentiating performance was achieved than using ADC alone (area under curve: 0.956 vs. 0.876, p = 0.042). Conclusion: Compared to DWI, DKI could provide additional data related to tumor heterogeneity with significantly better differentiating performance. Its derived quantitative metrics could serve as a promising imaging biomarker for differentiating malignant from benign masses in head and neck region.