Overproduction of Glutathione by L-Cysteine Addition and a Temperature-shift Strategy

Gong-Yuan Wei,Da-Hui Wang,Jian Chen 한국생물공학회 2008 Biotechnology and Bioprocess Engineering Vol.13 No.3

The present study investigated the effects of three constituent amino acids on glutathione production in flask culture of Candida utilis. Although L-glutamic acid and glycine had little impact on cell growth and glutathione biosynthesis, L-cysteine positively influenced glutathione production, despite inhibiting cell growth when it was added prior to stationary phase. Adding 8 mmol/L of L-cysteine to the culture broth at 16 h boosted glutathione production by 91%, increasing the intracellular glutathione content by 106% compared to untreated controls. A temperature-shift strategy, in which we shifted batch and fed-batch cultures of C. utilis from 30 to 26℃, also significantly enhanced glutathione production. Applying both strategies (i.e. adding 20 mmol/L L-cysteine and shifting the temperature from 30 to 26℃) at 33 h enhanced the glutathione concentration and the intracellular glutathione content to 1,312 mg/L and 3.75%, respectively, during fed-batch cultivation (glucose feeding at a constant rate of 18.3 g/h). The average specific glutathione production rate under this condition was 129% higher than that of the control without strategy.

Pretreatment and Saccharification of Rice Hulls for the Production of Fermentable Sugars

Gong-Yuan Wei,Wa Gao,II-Hyuck Jin,Su-Young Yoo,이재헌,Chung-Han Chung,이진우 한국생물공학회 2009 Biotechnology and Bioprocess Engineering Vol.14 No.6

Hydrolytic conditions of rice hulls by acid and alkaline treatments before enzymatic saccharification were optimized in this study. Based on the results of single-factor experiments and an orthogonal array experiment, reaction time was found to be the most important factor for the acidic hydrolysis of rice hulls. Maximum yield of sugars from 1 g of rice hulls by acidic treatment under optimized conditions was 213.6 mg. The yield of lignin removal from acidic pretreated rice hulls by alkaline treatment increased with increase in reaction temperature and time. The amount of sugars obtained from 1 g of pretreated rice hulls by enzymatic saccharification was 307.7 mg, and the conversion rate of sugars from crude fibers in pretreated rice hulls was about 72%. Instrumental analyses with FTIR and SEM indicated that lignin in rice hulls was partially removed by alkaline treatment, and the structure of rice hulls became deformed and more fibers were exposed to cellulases after acidic treatment

Inequalities in Awareness and Attitude towards HPV and Its Vaccine between Local and Migrant Residents Who Participated in Cervical Cancer Screening in Shenzhen, China

Wei Lin,Yueyun Wang,Zhihua Liu,Bin Chen,Shixin Yuan,Bo Wu,Lin Gong 대한암학회 2020 Cancer Research and Treatment Vol.52 No.1

Purpose A cross-sectional survey was conducted to evaluate the differences on awareness and attitude towards human papillomavirus (HPV) and its vaccine between local and migrant residents who participated in cervical cancer screening in Shenzhen, China. Materials and Methods A total of 9,855 females sampled from healthcare institutions in 20 street blocks through the Cervical Cancer Prevention Network were surveyed in this study by a self-administered questionnaire. Multivariate logistic regression was conducted to explore the role of the hukou and resident status in the willingness to receive HPV vaccination. Results Local residents had a relatively higher awareness of HPV (62.0% vs. 35.6% vs. 29.9%, p < 0.001) and its vaccine (35.3% vs. 15.4% vs. 14.8%, p < 0.001), as well as a higher willingness to receive HPV vaccination (68.5% vs. 62.5% vs. 56.2%, p < 0.001) than non-permanent residents and floating population. Except for age, education level, marital status, monthly income, having daughter(s), and heard of HPV and its vaccine, the hukou and resident status significantly associated with the willingness to receive HPV vaccination (local residents vs. floating population: odds ratio, 1.216; 95% confidence interval, 1.057 to 1.398). None significant difference on the associated factors was found between local residents and internal migrants (p for interactions > 0.05). Conclusion Inequalities in awareness and attitude towards HPV and its vaccine existed between local and migrant residents in Shenzhen. The hukou and resident status did impact on the willingness to receive HPV vaccination, therefore, it is critical to implement effective health education campaigns on HPV and its vaccine among internal migrants.

Buckling response of offshore pipelines under combined tension and bending

Gong, Shun-Feng,Ni, Xing-Yue,Yuan, Lin,Jin, Wei-Liang Techno-Press 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.41 No.6

Offshore pipelines have to withstand combined actions of tension and bending during deepwater installation, which can possibly lead to elliptical buckle and even catastrophic failure of whole pipeline. A 2D theoretical model initially proposed by Kyriakides and his co-workers which carried out buckling response analysis of elastic-plastic tubes under various load combinations, is further applied to investigate buckling behavior of offshore pipelines under combined tension and bending. In association with practical pipe-laying circumstances, two different types of loadings, i.e., bent over a rigid surface in the presence of tension, and bent freely in the presence of tension, are taken into account in present study. In order to verify the accuracy of the theoretical model, numerical simulations are implemented using a 3D finite element model within the framework of ABAQUS. Excellent agreement between the results validates the effectiveness of this theoretical method. Then, this theoretical model is used to study the effects of some important factors such as load type, loading path, geometric parameters and material properties etc. on buckling behavior of the pipes. Based upon parametric studies, a few significant conclusions are drawn, which offer a theoretical reference for design and installation monitoring of deepwater pipelines.

New Lignan Isolated from Phyllanthus niruri Linn. Structure Elucidation by NMR Spectroscopy

Wei, Wan-Xing,Gong, Xing-guo,Ishrud, Omar,Pan, Yuan-Jiang Korean Chemical Society 2002 Bulletin of the Korean Chemical Society Vol.23 No.6

Current Evidence on the Association between rs3757318 of C6orf97 and Breast Cancer Risk: a Meta-Analysis

Hong, Yuan,Chen, Xue-Qin,Li, Jiao-Yuan,Liu, Cheng,Shen, Na,Zhu, Bei-Bei,Gong, Jing,Chen, Wei Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.19

Background: A common genetic variant rs3757318, located in intron of C6orf97, was firstly identified to be associated with breast cancer (BC) risk by a genome-wide association (GWA) study. However, subsequent validation studies with different ethnicities have yielded conflicting results. Materials and Methods: We performed a meta-analysis to synthesize all available data for evaluating the precise effect of this variant on BC susceptibility. Results: A total of 8 articles containing 11 studies with 62,891 cases and 65,635 controls were included in this meta-analysis. When compared to the G allele, the rs3757318-A allele was significantly associated with BC risk with the pooled OR of 1.21 (95% CI=1.15 - 1.29, P<0.001) but with obvious between-study heterogeneity (P=0.040). Stratified analysis suggested that diversity of ethnicity along with control source may explain part of the heterogeneity. Similarly, significant associations were also identified in heterozygote, homozygote, dominant and recessive genetic models. Sensitivity and publication bias analyses indicated robust stability of our results. Conclusions: Our present meta-analysis demonstrated that the variant rs3757318 is associated with increased BC risk. Nevertheless, further studies are needed to clarify the underlying biological mechanisms.

Analysis of Altered Baseline Brain Activity in Drug-Naive Adult Patients with Social Anxiety Disorder Using Resting-State Functional MRI

Changjian Qiu,Yuan Feng,Yajing Meng,Wei Liao,Xiaoqi Huang,Su Lui,Chunyan Zhu,Huafu Chen,Qiyong Gong,Wei Zhang 대한신경정신의학회 2015 PSYCHIATRY INVESTIGATION Vol.12 No.3

ObjectiveaaWe hypothesize that the amplitude of low-frequency fluctuations (ALFF) is involved in the altered regional baseline brain function in social anxiety disorder (SAD). The aim of the study was to analyze the altered baseline brain activity in drug-naive adult patients with SAD. MethodsaaWe investigated spontaneous and baseline brain activities by obtaining the resting-state functional magnetic resonance imaging data of 20 drug-naïve adult SAD patients and 19 healthy controls. Voxels were used to analyze the ALFF values using one- and two-sample t-tests. A post-hoc correlation of clinical symptoms was also performed. ResultsaaOur findings show decreased ALFF in the bilateral insula, left medial superior frontal gyrus, left precuneus, left middle temporal gyrus, right middle temporal pole, and left fusiform gyrus of the SAD group. The SAD patients exhibited significantly increased ALFF in the right inferior temporal gyrus, right middle temporal gyrus, bilateral middle occipital gyrus, orbital superior frontal gyrus, right fusiform gyrus, right medial superior frontal gyrus, and left parahippocampal gyrus. Moreover, the Liebowitz Social Anxiety Scale results for the SAD patients were positively correlated with the mean Z values of the right middle occipital and right inferior occipital but showed a negative correlation with the mean Z values of the right superior temporal gyrus and right medial superior frontal gyrus. ConclusionaaThese results of the altered regional baseline brain function in SAD suggest that the regions with abnormal spontaneous activities are involved in the underlying pathophysiology of SAD patients.

Buckling response of offshore pipelines under combined tension and bending

Shun-feng Gong,Xing-yue Ni,Lin Yuan,Wei-liang Jin 국제구조공학회 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.41 No.6

Offshore pipelines have to withstand combined actions of tension and bending during deepwater installation, which can possibly lead to elliptical buckle and even catastrophic failure of whole pipeline. A 2D theoretical model initially proposed by Kyriakides and his co-workers which carried out buckling response analysis of elastic-plastic tubes under various load combinations, is further applied to investigate buckling behavior of offshore pipelines under combined tension and bending. In association with practical pipe-laying circumstances, two different types of loadings, i.e., bent over a rigid surface in the presence of tension, and bent freely in the presence of tension, are taken into account in present study. In order to verify the accuracy of the theoretical model, numerical simulations are implemented using a 3D finite element model within the framework of ABAQUS. Excellent agreement between the results validates the effectiveness of this theoretical method. Then, this theoretical model is used to study the effects of some important factors such as load type, loading path, geometric parameters and material properties etc. on buckling behavior of the pipes. Based upon parametric studies, a few significant conclusions are drawn, which offer a theoretical reference for design and installation monitoring of deepwater pipelines.

Modeling the effect of vibration on the quality of stirred yogurt during transportation

Anna Lu,Xinxin Wei,Ruikang Cai,Shujun Xiao,Haina Yuan,Jinyan Gong,Bingquan Chu,Gongnian Xiao 한국식품과학회 2020 Food Science and Biotechnology Vol.29 No.7

When transporting yogurt, vibrations and sharpmovements can damage its quality. This study developed amodel to connect the changes in yogurt quality with thetransportation distance as simulated by the total number ofvibrations. Linear regression analysis showed that therewas a significant negative correlation between the waterholding capacity and hardness of the yogurt over the sametransport distance (p\0.05). The yogurt vibration modelwas established by combining principal component analysiswith a Back-Propagation Artificial Neural Networkmodel. The number of training iterations was 2669, with acorrelation coefficient of 0.96611, indicating that the modelwas reliable. The optimal transportation distance wasdetermined to be within the range from 20 rpm for 8 h to100 rpm for 4 h.

Efficient production of glutathione using hydrolyzate of banana peel as novel substrate

Xue-Dong Chen,Gong-Yuan Wei,Jun-Li Zhang,Ying-Ying Dong 한국화학공학회 2011 Korean Journal of Chemical Engineering Vol.28 No.7

The hydrolyzate of banana peels containing abundant fermentable sugars as glucose, xylose, mannose,and arabinose was successfully used as a novel substrate for the efficient production of glutathione by Candida utilis SZU 07-01. Xylose was first selected as the sole carbon source for glutathione production, medium optimization for better cell growth and higher glutathione using response surface methodology consisting of PB design, the steepest ascent experiment and CCD was carried out, and the optimal combination of nutrients was obtained as follows: xylose 20 g/L, (NH_4)-2SO_4 9.59 g/L, KH_2PO_4 3 g/L, L-methionine 5.72 g/L and MgSO_4 0.20 g/L. The maximum dry cell weight and glutathione achieved using the optimized medium were 7.36 g/L and 154.32 mg/L, respectively. Following with the content in this medium, other sugars like glucose, mannose and arabinose were chosen as the sole carbon source and all tested available for glutathione production. Based on these results, the hydrolyzate of banana peels was selected as a novel substrate, and a high DCW of 7.68 g/L and glutathione yield of 111.33 mg/L were obtained with the initial sugar concentration of 20 g/L in the hydrolyzate of banana peels.