Bioactive Compounds / Food Microbiology : Improvement of Natamycin Production by Cholesterol Oxidase Overexpression in Streptomyces gilvosporeus

( Miao Wang ),( Shao Hua Wang ),( Gong Li Zong ),( Zhong Wen Hou ),( Fei Liu ),( D Joshua Liao ),( Xi Qiang Zhu ) 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.2

Natamycin is a widely used antifungal antibiotic. For natamycin biosynthesis, the gene pimE encodes cholesterol oxidase, which acts as a signalling protein. To confirm the positive effect of the gene pimE on natamycin biosynthesis, an additional copy of the gene pimE was inserted into the genome of Streptomyces gilvosporeus 712 under the control of the ermE* promoter (permE*) using intergeneric conjugation. Overexpression of the target protein engendered 72% and 81% increases in the natamycin production and cell productivity, respectively, compared with the control strain. Further improvement in the antibiotic production was achieved in a 1 L fermenter to 7.0 g/l, which was a 153% improvement after 120 h cultivation. Exconjugants highly expressing pimE and pimM were constructed to investigate the effects of both genes on the increase of natamycin production. However, the co-effect of pimE and pimM did not enhance the antibiotic production obviously, compared with the exconjugants highly expressing pimE only. These results suggest not only a new application of cholesterol oxidase but also a useful strategy to genetically engineer natamycin production.

Vibration Reduction Control of In-Pipe Intelligent Isolation Plugging Tool Based on Deep Reinforcement Learning

Xingyuan Miao,Hong Zhao,Boxuan Gao,Tingting Wu,Yanguang Hou 한국정밀공학회 2022 International Journal of Precision Engineering and Vol.9 No.6

Compared with traditional plugging methods, the in-pipe intelligent isolation plugging tool (IPT) is advantageous in safety and work efficiency. However, during the plugging process, the flow field around the IPT changes drastically, resulting in vortex-induced vibration and potential failure of the plugging operation. In this study, three foldable spoilers were designed at the tail of the IPT to optimize the flow field. The vibration of the IPT can be alleviated by adjusting the angles of the spoilers. A vibration reduction control system of the IPT was designed based on deep reinforcement learning. First, we conducted an experiment for vibration reduction system. Second, a nonlinear model of the pressure difference based on experimental data was established. Then, a multi-agent self-learning system based on the deep Q-network (DQN) was designed, and the optimal actions were selected in each agent to adjust the spoiler angles during the plugging process. Finally, a controller based on fuzzy reinforcement learning was proposed to flip the spoilers to the optimized angles. The results show that the vibration reduction control system of the IPT reduced the pressure difference by an average of 28.32%, which indicates the stability of the plugging process and a successful reduction of the IPT vibration.

Characterization and Mechanism Analysis of Flexible UV Irradiated PAN-Based Carbon Fiber Membranes Prepared

Chao Hou,Miao Yu,Binjie Xin 한국섬유공학회 2023 Fibers and polymers Vol.24 No.12

To enhance the flexibility of electrostatically spun PAN-based carbon nanofiber films for wearable textile applications, this study aimed to prepare PAN nanofiber films by incorporating the 1173 photoinitiator. Subsequently, UV irradiation, pre-oxidation treatment, and high-temperature carbonization processes were employed to develop PAN nanofiber films with improved mechanical properties. The results indicated that UV irradiation treatment significantly promoted the degree of pre-oxidation reaction in PAN nanofiber membranes. Thermal performance characterization demonstrated that UV irradiation reduced the initiation temperature of the cyclization reaction and mitigated the concentration of exothermic phenomena. Raman spectra analysis revealed increased graphitization in the carbon nanofiber film following UV irradiation, as evidenced by a decrease in the ID/IG value to 0.908. This suggests that UV irradiation facilitated stable carbonization and enhanced the graphitization of the carbon fiber within PAN nanofiber films. Moreover, the stress–strain curve indicated that the breaking strength of the nanofiber film reached 1.45 MPa after 20 min of UV irradiation while maintaining an elongation at a break of 3.5%, demonstrating its remarkable strength and toughness. The resulting flexible carbon nanofiber film holds great potential for medical textiles, filtration membranes, flexible capacitors, and more applications.

Hypoxia Induced High Expression of Thioredoxin Interacting Protein (TXNIP) in Non-small Cell Lung Cancer and its Prognostic Effect

Li, Yan,Miao, Li-Yun,Xiao, Yong-Long,Huang, Mei,Yu, Min,Meng, Kui,Cai, Hou-Rong Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.7

Although associations between thioredoxin interacting protein (TXNIP) and cancers have been recognized, the effects of TXNIP on non-small cell lung cancer (NSCLC) prognosis remained to be determined in detail. In addition, while hypoxia is a key characteristic of tumor cell growth microenvironment, the effect of hypoxia on TXNIP expression is controversial. In this study, formaldehyde fixed and paraffin embedded (FFPE) samples of 70 NSCLC patients who underwent resection between January 2010 and December 2011 were obtained. Evaluation of TXNIP and hypoxia inducible factor-$1{\alpha}$ ($HIF-1{\alpha}$) protein expression in FFPE samples was made by immunohistochemistry. By Kaplan-Meier method, patients with high TXNIP expression demonstrated a significantly shorter progression free survival (PFS) compared with those with low TXNIP expression (18.0 months, 95%CI: 11.7, 24.3 versus 23.0 months, 95%CI: 17.6, 28.4, P=0.02). High TXNIP expression level was also identified as an independent prognostic factor by Cox regression analysis (adjusted hazard ratio: 2.46; 95%CI: 1.08, 5.56; P=0.03). Furthermore, TXNIP expression was found to be significantly correlated with $HIF-1{\alpha}$ expression (Spearman correlation=0.67, P=0.000). To further confirm correlations, we established a tumor cell hypoxic culture model. Expression of TXNIP was up-regulated in all three NSCLC cell lines (A549, SPC-A1, and H1299) under hypoxic conditions. This study suggests that hypoxia induces increased TXNIP expression in NSCLC and high TXNIP expression could be a poor prognostic marker.

Elevated Platelets Enhance Cancer Cell Migration, Promote Hematogenous Metastasis and Associate with a Poor Prognosis in Advanced Non-small Cell Lung Cancer Cases

Li, Yan,Miao, Li-Yun,Xiao, Yong-Long,Cai, Hou-Rong,Zhang, De-Ping Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.1

Although correlations between platelets and lung cancer has been recognized, effects on non-small cell lung cancer (NSCLC) metastasis remain to be determined in detail. In the present study, wound healing assays revealed a role of platelets in NSCLC cell migration. Thus the mean migration rate of lung adenocarcinoma A549 cells was significantly elevated after co-culture with platelets ($81.7{\pm}0.45%$ vs $41.0{\pm}3.50%$, P<0.01). Expression of GAPDH was examined by reverse transcription-polymerase chain reaction to study the effect of platelets on NSCLC cell proliferation. The result showed that the proliferation of A549 and SPC-A1 cells was not affected. Mouse models were established by transfusing A549 cells and SPC-A1 cells into mice lateral tail veins. We found tumor metastasis nodules in lungs to be increased significantly after co-transfusion with platelets (in A549, $4.33{\pm}0.33$ vs $0.33{\pm}0.33$, P=0.01; in SPC-A1, $2.67{\pm}0.33$ vs $0.00{\pm}0.00$, P=0.01). In addition, consecutive inoperable patients with newly diagnosed NSCLC (TNM stage III or IV) between January 2009 and December 2011 were retrospectively reviewed. Using the Kaplan-Meier method, NSCLC patients with a high platelet counts demonstrated a significantly shorter progression free survival compared with those with a low platelet count (> $200{\times}10^9/L$, 3 months versus ${\leq}200{\times}10^9/L$, 5 months, P=0.001). An elevated platelet count was also identified as an independent prognostic factor by Cox regression analysis for prgression free survival (adjusted hazard ratio: 1.69; 95% CI: 1.16, 2.46; P=0.006). This study suggested that platelets might contribute to the hematogenous metastatic process by promoting cancer cell migration, which eventually affects the prognosis of NSCLC.

Effect of Stirrup Corrosion and Fire on Shear Behavior of Reinforced Concrete Beams

Jialiang Liu,Jijun Miao,Guangzhong Ba,Jiangzhuang Xiao,Dongshuai Hou 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.9

This article presents an investigation on corrosion damage effects on the shear bearing capacity of reinforced concrete (RC) beams after a fire. Accelerated corrosion tests were conducted using four RC beams designed with corrosion crack widths ranging from 0.1 mm to 0.3 mm to simulate an aggressive corrosion-prone environment. One control beam (B1) did not undergo accelerated corrosion. The fire test was conducted separately on each beam for two hours to explore how the different widths of corrosive cracks affect heat propagation at elevated fire-induced temperatures. A residual capacity test determined the effects of corrosion on the beams’ residual shear strength after a fire. The experimental results showed that corrosion cracks accelerate the heat propagation in concrete during a fire; moreover, the post-fire residual shear strength for corroded RC beams slightly decreased with an increasing degree of corrosion on the stirrups. The authors also developed a corresponding simplified calculating method to determine residual shear strength, which showed shear design provisions that could improve some existing codes.

Law and Early Warning of Vertical Sluice Cluster Displacements in Soft Coastal Soil

Xing Yang,Cong Yuan,Miao Hou,Chengyang Zhou,Yan Ju,Fei Qi 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.2

The vertical displacement, which is the product of natural sources and human activities, is the key factor affecting the sluice safety. This study provides a systematic approach used for analyzing the law and early warning of sluice cluster vertical displacements in coastal soft soil locations. Two important methods, including probability analysis and principal component analysis (PCA), are used to obtain the necessary information in this study. Among them, PCA is mainly used to identify the risk indices during vertical deformations of sluice cluster. As case studies, 27 sluices in a cluster in Northern Jiangsu Province's coastal area in China are chosen and 14 variables related to sluice uplift, settlement and differential settlement deformations are used. The PCA and additional evidence from the sluice deformation law are used to identify three variables as risk indices, including maximum differential settlement (MMDS), maximum cumulative vertical settlement (MCVS) and maximum cumulative vertical uplift (MCVU). This study divides the risk levels into five grades (i.e., Level 1 to Level 5) based on the selected risk indices and determines their risk thresholds based on the in-situ deformation data from 2010 to 2020. In general, the results demonstrate that the newly proposed approach exhibits an acceptable performance. However, the influence of epistemic and aleatory uncertainties on this study is worthy of further discussion in the future.

Effect of serotonin on the cell viability of the bovine mammary alveolar cell-T (MAC-T) cell line

Xusheng Dong,Chen Liu,Jialin Miao,Xueyan Lin,Yun Wang,Zhong-Hua Wang,Qiuling Hou 한국축산학회 2022 한국축산학회지 Vol.64 No.5

5-Hydroxytryptamine (5-HT), a monoamine, as a local regulator in the mammary gland is achemical signal produced by the mammary epithelium cell. In cows, studies have shown that5-HT is associated with epithelial cell apoptosis during the degenerative phase of the mammarygland. However, studies in other tissues have shown that 5-HT can effectively promotecell viability. Whether 5-HT could have an effect on mammary cell viability in dairy cows isstill unknown. The purpose of this study was to determine: (1) effect of 5-HT on the viability ofbovine mammary epithelial cells and its related signaling pathways, (2) interaction betweenprolactin (PRL) and 5-HT on the cell viability. The bovine mammary alveolar cell-T (MAC-T)were cultured with different concentrations of 5-HT for 12, 24, 48 or 72 hours, and then wereassayed using cell counting kit-8, polymerase chain reaction (PCR) and immunobloting. Theresults suggested that 20 μM 5-HT treatment for 12 or 24 h promote cell viability, which wasmainly induced by the activation of 5-HT receptor (5-HTR) 1B and 4, because the increasecaused by 5-HT vanished when 5-HTR 1B and 4 was blocked by SB224289 and SB204070. And protein expression of mammalian target of rapamycin (mTOR), eukaryotic translationelongation factor 2 (eEF2), janus kinase 2 (JAK2) and signal transducer and activator of transcription5 (STAT5) were decreased after blocking 5-HT 1B and 4 receptors. When MAC-Tcells were treated with 5-HT and PRL simultaneously for 24 h, both the cell viability and thelevel of mTOR protein were significantly higher than that cultured with 5-HT or PRL alone. Inconclusion, our study suggested that 5-HT promotes the viability of MAC-T cells by 5-HTR1B and/or 4. Furthermore, there is a reciprocal relationship between PRL and 5-HT.

Performance Assessment of InSAR-Based Vertical Displacement Monitoring of Sluices in Coastal Soft Soil Area

Xing Yang,Dongmei Wang,Yongping Xu,Miao Hou,Zhihuan Wang 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.1

Sluices are main flood control infrastructures in coastal areas, where soft rock and soft soil are widely distributed. In soft soil areas, the vertical displacement of sluice is common, which is the main factor affecting the sluice safety. So, it is very important for sluice safety control according to the prototypical observations on deformation. Considering some drawbacks of leveling, such as it can only provide a limited number of points and requires time-consuming field work, this paper evaluates the performance of Interferometric Synthetic Aperture Radar (InSAR)-based method in monitoring long-term vertical displacement deformations of sluices.Taking 12 sluices in Northern Jiangsu, China as an example, 129 Sentinel-1 C-band VV-polarizatio ascending SAR images that span the period from April 2015 to January 2020 were used to monitor their vertical displacement deformations. The leveling results are made to verify the accuracy and reliability of Permanent Scatterer InSAR (PSInSAR) method. The validation indicates good agreement between PSInSAR results and leveling results. Considering the higher accuracy of leveling, PSInSAR method is more suitable as an auxiliary technology besides leveling method to focus on the early warning of sluice deformation risk events.

Collateral Flow in Magnetic Resonance Angiography: Prognostic Value for Vertebrobasilar Stenosis With Stroke Recurrence

Long Yan,Ying Yu,Kaijiang Kang,Zhikai Hou,Min Wan,Weilun Fu,Rongrong Cui,Yongjun Wang,Zhongrong Miao,Xin Lou,Ning Ma 대한신경과학회 2022 Journal of Clinical Neurology Vol.18 No.5

Background and Purpose Intracranial vertebrobasilar atherosclerotic stenosis (IVBAS) is a major cause of posterior circulation stroke. Some patients suffer from stroke recurrence despite receiving medical treatment. This study aimed to determine the prognostic value of a new score for the posterior communicating artery and the P1 segment of the posterior cerebral artery (PCoA-P1) for predicting stroke recurrence in IVBAS. Methods We retrospectively enrolled patients with severe IVBAS (70%–99%). According to the number of stroke recurrences, patients were divided into no-recurrence, single-recurrence, and multiple-recurrences groups. We developed a new 5-point grading scale, with the PCoA-P1 score ranging from 0 to 4 based on magnetic resonance angiography, in which primary collaterals were dichotomized into good (2–4 points) and poor (0 or 1 point). Stroke recurrences after the index stroke were recorded. Patients who did not experience stroke recurrence were compared with those who experienced single or multiple stroke recurrences. Results From January 2012 to December 2019, 176 patients were enrolled, of which 116 (65.9%) had no stroke recurrence, 35 (19.9%) had a single stroke recurrence, and 25 (14.2%) had multiple stroke recurrences. Patients with single stroke recurrence (odds ratio [OR]= 4.134, 95% confidence interval [CI]=1.822–9.380, p=0.001) and multiple stroke recurrences (OR=6.894, 95% CI=2.489–19.092, p<0.001) were more likely to have poor primary collaterals than those with no stroke recurrence. Conclusions The new PCoA-P1 score appears to provide improve predictions of stroke recurrence in patients with IVBAS