Oxygen Limitation Improves Ganoderic Acid Biosynthesis in Submerged Cultivation of Ganoderma lucidum

Wen-Xian Zhang,Jian-Jiang Zhong 한국생물공학회 2013 Biotechnology and Bioprocess Engineering Vol.18 No.5

The effects of oxygen limitation on the production of ganoderic acid (GA), a secondary metabolite with antitumor activity, and on transcription levels of triterpene biosynthesis genes were investigated in liquid cultures of Ganoderma lucidum. A low oxygen supply level was beneficial to total GA biosynthesis, but negative to the cell growth. The higher GA production was obtained under micro-aerobic conditions (i.e. initial overall kLa values at 0.02 and 0.13/h). The maximum GA production of 272.3 ± 11.5 mg/L was obtained at an initial overall kLa of 0.13/h, which was 1.7-fold that at a normal cultivation condition (an initial kLa of 5.51/h). For four major individual GAs, the production level of GA-Mk, -T, -S, and -Me in the hypoxia-induced cells was increased by 50, 87,62, and 111%, compared with that of the control, respectively. Meanwhile, the transcriptions of four key genes encoding 3-hydroxy-3-methylglutaryl coenzyme A reductase, mevalonate-5-pyrophosphate decarboxylase, squalene synthase and squalene epoxidase in the triterpene biosynthetic pathway were up-regulated under the hypoxia condition (at an initial kLa of 0.13/h). Reactive oxygen species was generated in response to hypoxia, which seemed to be involved in the regulation of GA biosynthesis. The information obtained provides an insight into the role of oxygen limitation in the GA biosynthesis, and will be helpful for optimizing the fermentation process on a large scale.

Protective Effects of Silibinin and Its Possible Mechanism of Action in Mice Exposed to Chronic Unpredictable Mild Stress

( Wen Jing Yan ),( Ying Chun Tan ),( Ji Cheng Xu ),( Xian Ping Tang ),( Chong Zhang ),( Peng Bo Zhang ),( Ze Qiang Ren ) 한국응용약물학회 2015 Biomolecules & Therapeutics(구 응용약물학회지) Vol.23 No.3

Silibinin, a natural flavonoid antioxidant isolated from extracts of the milk thistle herb, has recently been identified as having antihepatotoxic and anticancer properties. In this paper, we investigated the effects of silibinin on behavior and neuroplasticity in mice subjected to chronic unpredictable mild stress (CUMS). After 5 consecutive weeks of CUMS, the mice were treated with silibinin (100 mg/kg, 200 mg/kg and 400 mg/kg by oral gavage) for 3 consecutive weeks. The results showed that silibinin administration significantly alleviated the CUMS-induced depressive-like behavior, including the total number of squares crossed and the frequency of rearing in the open field test, the immobility time in the tail suspension test and the forced swimming test. Furthermore, silibinin treatment increased the levels of brain-derived neurotrophic factor (BDNF), serotonin (5-HT) and norepinephrine (NE) in the prefrontal cortex and hippocampus. Our study provides new insight into the protective effects of silibinin on the depressive status of CUMS mice, specifically by improving neuroplasticity and neurotransmission.

Synthesis and Characterization of MoS₂/Graphene-TiO₂ Ternary Photocatalysts for High-Efficiency Hydrogen Production under Visible Light

Zhang, Feng-Jun,Kong, Cui,Li, Xuan,Sun, Xian-Yang,Xie, Wen-Jie,Oh, Won-Chun The Korean Ceramic Society 2019 한국세라믹학회지 Vol.56 No.3

Ternary MoS₂/graphene (G)-TiO₂ photocatalysts were prepared by a simple hydrothermal method. The morphology, phase structure, band gap, and catalytic properties of the prepared samples were investigated by X-ray diffraction, Raman spectroscopy, scanning electron microscopy, UV-vis spectrophotometry, and Brunauer-Emmett-Teller surface area measurement. The H₂ production efficiency of the prepared catalysts was tested in methanol-water mixture under visible light. MoS₂/G-TiO₂ exhibited the highest activity for photocatalytic H₂ production. For 5 wt.% and 1 wt.% MoS₂ and graphene (5MT-1G), the production rate of H₂ was as high as 1989 µmol^-1h^-1. The catalyst 5MT-1G showed H₂ production activity that was ~ 11.3, 5.6, and 4.1 times higher than those of pure TiO₂, 1GT, and 5MT, respectively. The unique structure and morphology of the MoS₂/G-TiO₂ photocatalyst contributed to its improved hydrogen production efficiency under visible light.

A Generative Adversarial Network to Denoise Depth Maps for Quality Improvement of DIBR-Synthesized Stereoscopic Images

Zhang Chuang,Sun Xian-wen,Xu Jiawei,Huang Xiao-yu,Yu Gui-yue,Park Seop Hyeong 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.4

Depth map quality is an important factor that aff ects the quality of synthesized stereoscopic images in stereoscopic visual communication systems using the depth image-based rendering (DIBR) technique. This paper proposes a method using a generative adversarial network (GAN) to denoise depth maps corrupted by several types of distortion. The generative network of the proposed GAN builds on convolutional layers, residual layers, and transposed convolutional layers with symmetric skip connections. The discriminative network of the proposed GAN is designed as a convolutional neural network. The generative network for denoising depth maps is trained with cropped depth maps where distortion is applied. Objective and subjective assessment of denoised depth maps and DIBR-synthesized stereoscopic images demonstrate that the proposed GAN eff ectively reduces the distortion in the depth maps and improves the quality of DIBR-synthesized stereoscopic images.

A new phenylethanoid glycoside with antioxidant and anti-HBV activity from Tarphochlamys affinis

Xian-Li Zhou,Qing-Wei Wen,Xing Lin,Shi-Jun Zhang,Ying-Xin Li,You-Jia Guo,Ren Bin Huang 대한약학회 2014 Archives of Pharmacal Research Vol.37 No.5

A new phenylethanoid glycoside, named taraffinisosideA (1), together with five known glycosideswere isolated from the stems and leaves of Tarphochlamysaffinis. The structure of taraffinisoside A was identified onthe basis of detailed spectral analysis. Compounds 1–4 and6 showed potent antioxidant activities with IC50 values of10.36, 19.73, 43.95, 15.30 and 46.04 lM by 1,1-diphenyl-2-picryhydrazyl radical-scavenging assay. Compounds 1, 2and 4 showed anti-HBV activities, with IC50 values of0.50, 0.72 and 0.26 mM for HBsAg and 0.93, 0.42 and0.07 mM for HBeAg, respectively.

RPSA Gene Mutants Associated with Risk of Colorectal Cancer among the Chinese Population

Zhang, Shan-Chun,Jin, Wen,Liu, Hui,Jin, Ming-Juan,Chen, Ze-Xin,Ding, Zhe-Yuan,Zheng, Shuang-Shuang,Wang, Li-Juan,Yu, Yun-Xian,Chen, Kun Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.12

The primary aim of this study was to evaluate the relationship of single nucleotide polymorphisms (SNPs) in ribosomal protein SA (RPSA) gene with colorectal cancer (CRC). A case-control study including 388 controls and 387 patients with CRC was conducted in a Chinese population. Information about socio-demography and living behavior factors was collected by a structured questionnaire. Three SNPs (rs2133579, rs2269349, rs7641291) in RPSA gene were genotyped by Illumina SnapShot method. Multiple logistic regression models were used for assessing the joint effects between tea consumption and SNPs on CRC. The subjects with rs2269349 CC genotype had a decreased risk for CRC (OR=0.60; 95%CI = 0.37-0.99), compared with TT/CT genotype after adjustment for covariates. A similar association of rs2269349 with rectal cancer was observed (OR=0.49; 95%CI=0.24-1.00). Further analyses indicated that this SNP could modify the protective effect of tea drinking on CRC. Among the subjects with rs2269349 TT/CT or rs2133579 AA/GA, there was a marginal significantly lower risk of CRC (OR and 95%CI: 0.63 and 0.39-1.01 for rs2269349; 0.64 and 0.40-1.02 for rs2133579) in tea-drinking subjects in comparison to non-tea-drinking subjects. Mutants in the RPSA gene might be associated with genetic susceptibility to CRC and influence the protective effect of tea consumption in the Chinese population.

A new phenylethanoid glycoside with antioxidant and anti-HBV activity from Tarphochlamys affinis

Zhou, Xian-Li,Wen, Qing-Wei,Lin, Xing,Zhang, Shi-Jun,Li, Ying-Xin,Guo, You-Jia,Huang, Ren-Bin 대한약학회 2014 Archives of Pharmacal Research Vol.37 No.5

A new phenylethanoid glycoside, named taraffinisoside A (1), together with five known glycosides were isolated from the stems and leaves of Tarphochlamys affinis. The structure of taraffinisoside A was identified on the basis of detailed spectral analysis. Compounds 1-4 and 6 showed potent antioxidant activities with $IC_{50}$ values of 10.36, 19.73, 43.95, 15.30 and $46.04{\mu}M$ by 1,1-diphenyl-2-picryhydrazyl radical-scavenging assay. Compounds 1, 2 and 4 showed anti-HBV activities, with $IC_{50}$ values of 0.50, 0.72 and 0.26 mM for HBsAg and 0.93, 0.42 and 0.07 mM for HBeAg, respectively.

Optimization of Nominal Mixing Ratio of Mg to B in Fabrication of Magnesium Diboride Bulk

Yun Zhang,Cheng Lu,Si Hai Zhou,Kookchae Chung,Wen Xian Li IEEE 2009 IEEE transactions on applied superconductivity Vol.19 No.3

<P>In this paper bulk magnesium diboride (Mg<SUB>x</SUB>B<SUB>2</SUB>) with x varying from 0.9 to 1.3 was prepared by solid state reaction. The Mg:B mixing ratio for ideal MgB<SUB>2</SUB> is 1:2. The samples were sintered at 800degC for 60 h. Quantitative X-ray diffraction (XRD) analysis was performed to obtain the lattice parameters, the microstrain, and the weight fraction of impurities using the Rietveld refinement method. It has been found that the fraction of pure MgB<SUB>2</SUB> phase increases from x = 0.9 to x = 1.1, and then decreases with further increases in x. Mg<SUB>1.1</SUB>B<SUB>2</SUB> exhibits the highest critical current density, J<SUB>c</SUB>, over other samples in both low fields and high fields. A direct correlation between J<SUB>c</SUB> and connectivity indicates that better connectivity, caused by smaller amounts of impurities, results in the best J<SUB>c</SUB> in Mg<SUB>1.1</SUB>B<SUB>2</SUB>.</P>

Risk Factors for the Rupture of Bifurcation Intracranial Aneurysms Using CT Angiography

Li Wen,Guang-xian Wang,Dong Zhang,Zhi-ping Wang,Liu-qing Yang,Lei Zhang 연세대학교의과대학 2016 Yonsei medical journal Vol.57 No.5

Purpose: To investigate the clinical and morphological characteristics in relation to risk of bifurcation intracranial aneurysm rupture. Materials and Methods: Data from 202 consecutive patients with 219 bifurcation aneurysms (129 ruptured and 90 unruptured) managed at the authors’ facility between August 2011 and July 2014 were retrospectively reviewed. Based on their clinical records and CT angiographic findings, the ability of risk factors to predict aneurysm rupture was assessed using statistical methods. Results: Age, hypertension, diabetes mellitus, and cerebral atherosclerosis were negatively correlated with aneurysm rupture. Aneurysms located in the middle cerebral artery, daughter artery ratio, lateral angle ratio (LA ratio), and neck width were negativelycorrelated with rupture. Aneurysms located in the anterior communicating artery, irregularity, with daughter sac, depth, width, maximum size, aspect ratio (AR), depth-to-width ratio, and bottleneck factor were significantly and positively correlated with rupture. Binary logistic regression model revealed that irregular shape [odds ratio (OR) 6.598] and AR (OR 3.507) strongly increasedthe risk of bifurcation aneurysm rupture, while age (OR 0.434), cerebral atherosclerosis (OR 0.125), neck width (OR 0.771), and LA ratio (OR 0.267) were negatively correlated with rupture (p<0.05). Receiver operating characteristic analysis revealedthe threshold values of AR and LA ratio to be 1.18 and 1.50, respectively. Conclusion: Age (≥60 yr), cerebral atherosclerosis, and aneurysms with a larger neck width and larger LA ratio are protective factorsagainst bifurcation aneurysm rupture. An aneurysm with an irregular shape and an increased AR reflect the greater likelihoodof a rupture.

MRI Findings of Primary CNS Lymphoma in 26 Immunocompetent Patients

Dong Zhang,Liang-Bo Hu,Tobias D Henning,Elisabeth M Ravarani,Li-Guang Zou,Xiao-Yuan Feng,Wen-Xian Wang,Li Wen 대한영상의학회 2010 Korean Journal of Radiology Vol.11 No.3

Objective: To record the MR imaging features of primary central nervous system lymphoma (PCNSL) and compare these features in monofocal and multifocal disease. Materials and Methods: Twenty-one cases of monofocal disease were compared to five cases of multifocal disease. All patients were examined by nonenhanced and contrast-enhanced MRI. Tumor location, tumor size, signal intensity, enhancement characteristics, age distribution, peritumoral edema, cystic changes, and the presence of calcifications were assessed. The MRI features were compared between the monofocal and multifocal disease cases. Results: The 26 cases, including both the monofocal and multifocal cases, exhibited 37 lesions. Contrast-enhanced images showed variable enhancement patterns: homogeneous enhancement (33 lesions), ring-like enhancement (2), and ‘open-ring-like’ enhancement (2). The ‘notch sign’ was noted in four of 33 homogeneously enhancing lesions. One case of hemorrhage and three cases of cystic formation were observed. Intra-tumoral calcification was not found. The frontal lobe, the corpus callosum and the basal ganglia were commonly affected in both the monofocal and multifocal groups. Tumor size differed significantly between the two groups (t = 3.129, p < 0.01) and mildly or moderately enhanced lesions were more frequently found in the monofocal group (p < 0.05). There was no statistical difference between perifocal edema (p > 0.05) and the signal characteristics (p > 0.05) between the two groups. Conclusion: Our data show that PCNSL has a variable enhancement pattern on MR images. We first reported two lesions with an ‘open-ring’ enhancement as well as four cases with a ‘notch sign’. Monofocal PCNSL cases typically have larger sized tumors with mild or moderate enhancement. Objective: To record the MR imaging features of primary central nervous system lymphoma (PCNSL) and compare these features in monofocal and multifocal disease. Materials and Methods: Twenty-one cases of monofocal disease were compared to five cases of multifocal disease. All patients were examined by nonenhanced and contrast-enhanced MRI. Tumor location, tumor size, signal intensity, enhancement characteristics, age distribution, peritumoral edema, cystic changes, and the presence of calcifications were assessed. The MRI features were compared between the monofocal and multifocal disease cases. Results: The 26 cases, including both the monofocal and multifocal cases, exhibited 37 lesions. Contrast-enhanced images showed variable enhancement patterns: homogeneous enhancement (33 lesions), ring-like enhancement (2), and ‘open-ring-like’ enhancement (2). The ‘notch sign’ was noted in four of 33 homogeneously enhancing lesions. One case of hemorrhage and three cases of cystic formation were observed. Intra-tumoral calcification was not found. The frontal lobe, the corpus callosum and the basal ganglia were commonly affected in both the monofocal and multifocal groups. Tumor size differed significantly between the two groups (t = 3.129, p < 0.01) and mildly or moderately enhanced lesions were more frequently found in the monofocal group (p < 0.05). There was no statistical difference between perifocal edema (p > 0.05) and the signal characteristics (p > 0.05) between the two groups. Conclusion: Our data show that PCNSL has a variable enhancement pattern on MR images. We first reported two lesions with an ‘open-ring’ enhancement as well as four cases with a ‘notch sign’. Monofocal PCNSL cases typically have larger sized tumors with mild or moderate enhancement.