High Levels of Malic Acid Production by the Bioconversion of Corn Straw Hydrolyte Using an Isolated Rhizopus Delemar Strain

Xingjiang Li,Ya Liu,Ying Yang,Hua Zhang,Hualin Wang,Yue Wu,Min Zhang,Ting Sun,Jieshun Cheng,Xuefeng Wu,Lijun Pan,Shaotong Jiang,Hongwei Wu 한국생물공학회 2014 Biotechnology and Bioprocess Engineering Vol.19 No.3

The microbial fermentation of malic acid,which is one of the most important organic acid platformsused widely in food and chemical engineering, hasattracted considerable interest. A malate production strainwas isolated, a mutation was induced, and regulation of themetabolic network was then conducted. The identificationresults showed that the malic acid production strain, HF-119, belonged to Rhizopus delemar. An analysis of themetabolic pathway showed that the malic acid flux of thisstrain occurred through three main pathways, and manybyproducts, such as succinic acid, fumaric acid andethanol, were produced. Although corn straw hydrolytewas used, the metabolism of xylose was not as rapid as thatof glucose. Subsequently, breeding of the strains andregulation of the metabolic network resulted in an increasein malate yield, and the strain HF-121 produced more than120 g/L malic acid within 60 h. The ability to producemalic acid from biomass hydrolyte highlights the industrialdevelopment potential of this strain.

Heteroexpression and Functional Characterization of Glucose 6-Phosphate Dehydrogenase from Industrial Aspergillus oryzae

( Hongwei Guo ),( Jinyao Han ),( Jingjing Wu ),( Hongwen Chen ) 한국미생물생명공학회(구 한국산업미생물학회) 2019 Journal of microbiology and biotechnology Vol.29 No.4

The engineered Aspergillus oryzae has a high NADPH demand for xylose utilization and overproduction of target metabolites. Glucose-6-phosphate dehydrogenase (G6PDH, E.C. 1.1.1.49) is one of two key enzymes in the oxidative part of the pentose phosphate pathway, and is also the main enzyme involved in NADPH regeneration. The open reading frame and cDNA of the putative A. oryzae G6PDH (AoG6PDH) were obtained, followed by heterogeneous expression in Escherichia coli and purification as a his6-tagged protein. The purified protein was characterized to be in possession of G6PDH activity with a molecular mass of 118.0 kDa. The enzyme displayed maximal activity at pH 7.5 and the optimal temperature was 50°C. This enzyme also had a half-life of 33.3 min at 40°C. Kinetics assay showed that AoG6PDH was strictly dependent on NADP+ (K_m = 6.3 μM, k_cat = 1000.0 s^-1, k_cat/K_m =158.7 s^-1·μM^-1) as cofactor. The K_m and k_cat/K_m values of glucose-6-phosphate were 109.7 s^-1·μM^-1 and 9.1 s^-1·μM^-1 respectively. Initial velocity and product inhibition analyses indicated the catalytic reaction followed a two-substrate, steady-state, ordered BiBi mechanism, where NADP⁺ was the first substrate bound to the enzyme and NADPH was the second product released from the catalytic complex. The established kinetic model could be applied in further regulation of the pentose phosphate pathway and NADPH regeneration of A. oryzae to improve its xylose utilization and yields of valued metabolites.

A Three-phase Hybrid Power Flow Algorithm for Meshed Distribution System with Transformer Branches and PV Nodes

Hongwei Li,Huabing Wu,Biyu Jiang,Anan Zhang,Wei Fang 대한전기학회 2016 Journal of Electrical Engineering & Technology Vol.11 No.1

Aiming at analyzing the power flow of the distribution systems with distribution transformer (DT) branches and PV nodes, a hybrid three-phase power flow methodology is presented in this paper. The incidence formulas among node voltages, loop currents and node current injections have been developed based on node-branch incidence matrix of the distribution network. The method can solve the power flow directly and has higher efficiency. Moreover, the paper provides a modified method to model DT branches by considering winding connections, phase shifting and off-nominal tap ratio, and then DT branches could be seen like one transmission line with the proposed power flow method. To deal with the PV nodes, an improved approach to calculate reactive power increment at each PV node was deduced based on the assumption that the positive-sequence voltage magnitude of PV node is fixed at a given value. Then during calculating the power flow at each iteration, it only needs to update current injection at each PV node with the proposed algorithm. The process is very simple and clear. The results of IEEE 4 nodes and the modified IEEE 34 nodes test feeders verified the correctness and efficiency of the proposed hybrid power flow algorithm.

Xinhuang Tablets Improve Intestinal Barrier Function via Regulating Epithelial Tight Junctions in Dextran Sulfate Sodium-Induced Ulcerative Colitis Mice

Meizhu Wu,Aling Shen,Youqin Chen,Liya Liu,Li Li,Senthilkumar Sankararaman,Hongwei Chen,Bin Guan,Zhixue Zhan,Shuhua Nan,Thomas J. Sferra,Jun Peng 한국식품영양과학회 2021 Journal of medicinal food Vol.24 No.1

Intestinal mucosal barrier dysfunction is involved in the pathogenesis of inflammatory bowel disease, including ulcerative colitis (UC). Xinhuang tablets (XHTs) have been prescribed for several kinds of inflammatory diseases, including UC, whereas its possible underlying molecular mechanisms had never been explored. Mouse model of UC was constructed by DSS treatment and followed by XHT treatment. Disease activity index, histopathological of colonic tissue, tumor necrosis factor-alpha (TNF-α), and serum amyloid A (SAA) levels in serum were further assessed. The underlying mechanism was further explored by determination of the expression of epithelial tight junction-related protein. XHT administration ameliorated dextran sulfate sodium (DSS)-induced clinical symptoms, colonic histological injury, and decreased the circulating levels of TNF-α and SAA. Moreover, XHT treatment significantly increased the protein levels of zona occludens (ZO)-1, whereas decreased the levels of phosphorylation of Elk-1. In conclusion, this study confirmed the therapeutic effects of XHT treatment on UC in a DSS-induced mouse model, and indicated that by increasing expression of epithelial tight junctions and decreasing phosphorylation of Elk-1 might be one of the underlying mechanisms of XHT treatment on UC.

Preparation of Nano-Convex and Nano-Concave-Patterned Polyimide Surfaces and their Nano-Tribological Behavior

Chunxia Wu,XIAOLIANG ZHANG,HONGWEI CHE,JINGBO MU,Guangshuo Wang,Zhixiao Zhang,Guohua Cui 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2017 NANO Vol.12 No.4

In this work, nano-convex-patterned polyimide surface (notated as 1-sample) and nano-concavepatterned polyimide surface (notated as 2-sample) were prepared by self-assembly and etching. Atomic force microscope (AFM) with a colloidal probe was used to examine the adhesion and nano-tribological behavior of the 1-sample and 2-sample. Results suggest that the 1-sample and 2-sample can decrease the surface friction and adhesive forces because of the decreased contact area between the contacting pairs. The friction forces of the 1-sample and 2-sample increased with the increase in sliding velocity and applied load. Moreover, the nano-concave pattern is more effective in reducing the adhesive force than the nano-convex pattern because of its higher surface roughness. However, the nano-convex patterning is more effective in reducing the friction force than the nano-concave patterning because of the smaller area of contact between the 2-sample and the colloidal probe.

Key Assumption to Evaluate the Mechanical Performance of Widened Voided-slab Bridge Due to Foundation Settlement

Wenqing Wu,Hongwei Shan,Song Yang,Zhangxiang Tang 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.4

In concrete bridge widening projects, it is a common practice to provide a monolithic connection between the existing and newdecks by casting an in situ concrete stitching slab. As a result, the differential foundation settlement between the two decks has aconsiderable effect on the concrete stitching slab and the widened bridge. The widened bridge noted as multi-girder bridge is asimple-supported, precast, voided-slab bridge, located on the Beijing–Shanghai Expressway in east of China. When using a grillageFinite Element Model (FEM) to model the mechanical behavior of the multi-girder bridge after it has been widened, the generalapproach to account for the effect of differential foundation settlement is to load a calculated forced vertical displacement to thebearing of each precast slab of the new bridge. However, there is no suitable mathematical model to be used for calculating the forceddisplacement for all new slab beams, which requires the ability to describe the transverse distribution mode of these forceddisplacement under a given differential foundation settlement. Under this background, an experimental study and finite elementanalysis are conducted to find this suitable mathematical model in this paper. Based on a comprehensive research results, a quadraticcurve model was considered to be a suitable mathematical model to meet the design need of such type of widened multi-girderbridge, and its quadratic equation was also derived in the paper. This finding is the key assumption for accurately analyzing themechanical behavior of a widened multi-girder bridge, with a grillage finite element model.

A Three-phase Hybrid Power Flow Algorithm for Meshed Distribution System with Transformer Branches and PV Nodes

Li, Hongwei,Wu, Huabing,Jiang, Biyu,Zhang, Anan,Fang, Wei The Korean Institute of Electrical Engineers 2016 Journal of Electrical Engineering & Technology Vol.11 No.1

Aiming at analyzing the power flow of the distribution systems with distribution transformer (DT) branches and PV nodes, a hybrid three-phase power flow methodology is presented in this paper. The incidence formulas among node voltages, loop currents and node current injections have been developed based on node-branch incidence matrix of the distribution network. The method can solve the power flow directly and has higher efficiency. Moreover, the paper provides a modified method to model DT branches by considering winding connections, phase shifting and off-nominal tap ratio, and then DT branches could be seen like one transmission line with the proposed power flow method. To deal with the PV nodes, an improved approach to calculate reactive power increment at each PV node was deduced based on the assumption that the positive-sequence voltage magnitude of PV node is fixed at a given value. Then during calculating the power flow at each iteration, it only needs to update current injection at each PV node with the proposed algorithm. The process is very simple and clear. The results of IEEE 4 nodes and the modified IEEE 34 nodes test feeders verified the correctness and efficiency of the proposed hybrid power flow algorithm.

Transcriptomic analyses reveal novel genes with sexually dimorphic expression in Takifugu rubripes brain during gonadal sex differentiation

Xufang Shen,Hongwei Yan,Lei Zhang,Zhen Yuan,Wenlei Liu,Yumeng Wu,Qi Liu,Xiaoyi Luo,Ying Liu 한국유전학회 2020 Genes & Genomics Vol.42 No.4

Background Quantification of mRNAs in gonads and other tissues at the early critical development stage of sex differentiation may help to provide a global view of regulatory mechanisms underlying sex differentiation. We have recently reported the transcriptomic profiling of fugu gonad associated with sex differentiation. Objectives This study attempted to identify the genes in the brain that are involved in gonadal differentiation and development. Methods In this study, a transcriptomic scan of potential candidate genes involved in sex differentiation was conducted in the brains of fugu larvae at 30 and 40 dah (morphological gonadal sex differentiation had not yet occurred). The dimorphic expression patterns of several candidate genes were verified using quantitative PCR. Results A total of 28.24 Gb of clean reads were obtained and 22,337 genes were identified in the brains of fugu larvae. These included 1008 novel genes that provide abundant data for functional analysis of sex differentiation. 229 genes were identified in the 30 dah larvae that were abundant in the XY brain and 21 that were abundant in the XX brain. In the 40 dah larvae, 325 genes were identified abundant in the XY brain and 174 were identified abundant in the XX brain. Conclusion This is the first investigation into the transcriptome of the fugu larvae brain at the early sex differentiation stage. The results obtained here will enhance the understanding of molecular mechanisms that underly fugu sex differentiation.

A flexible piezoelectric-triboelectric hybrid nanogenerator in one structure with dual doping enhancement effects

Yang Xiude,Li Ping,Wu Bo,Li Hongwei,Zhou Guangdong 한국물리학회 2021 Current Applied Physics Vol.32 No.-

For achieving more effective mechanical energy conversion, based on low-cost and flexible polydimethylsiloxane (PDMS) and polyvinylidene fluoride (PVDF) polymer film as triboelectric and piezoelectric function layer respectively, a polymer-based hybrid piezoelectric-triboelectric nanogenerator (PT-NG) with a structure of Al/ PVDF/Cu-PDMS/indium tin oxide (ITO)/polyethylene terephthalate (PET) has been demonstrated. The device has realized the simultaneous triboelectric and piezoelectric conversions in one structure. In addition, when PDMS and PVDF are further modified by graphene quantum dot (GQD) and titanium dioxide (TiO2) nanoparticles respectively, both triboelectric and piezoelectric outputs of the modified device are greatly enhanced synchronously. The experimental results have indicated that the increase of triboelectric output is due to the improvement of dielectric properties of PDMS film doped with conductive GQDs as well as the enhancement of the effective contact caused by the change of PDMS surface microstructure. While the promotion of piezoelectric output is mainly attributed to the fact that PVDF film after TiO2 modification induces more polarized β phase with a polarization-free process. Accordingly, the modified device converts mechanical energy into electricity more effectively, which shows a promising prospect in the fields of flexibility display, electronic skin, wearable electronic products and self-powered sensors.

Enteric dysbiosis-linked gut barrier disruption triggers early renal injury induced by chronic high salt feeding in mice

Jingjuan Hu,Haihua Luo,Jieyan Wang,Wenli Tang,Junqi Lu,Shan Wu,Zhi Xiong,Guizhi Yang,Zhenguo Chen,Tian Lan,Hongwei Zhou,Jing Nie,Yong Jiang,Peng Chen 생화학분자생물학회 2017 Experimental and molecular medicine Vol.49 No.-

Chronic high-salt diet-associated renal injury is a key risk factor for the development of hypertension. However, the mechanism by which salt triggers kidney damage is poorly understood. Our study investigated how high salt (HS) intake triggers early renal injury by considering the ‘gut-kidney axis’. We fed mice 2% NaCl in drinking water continuously for 8 weeks to induce early renal injury. We found that the ‘quantitative’ and ‘qualitative’ levels of the intestinal microflora were significantly altered after chronic HS feeding, which indicated the occurrence of enteric dysbiosis. In addition, intestinal immunological gene expression was impaired in mice with HS intake. Gut permeability elevation and enteric bacterial translocation into the kidney were detected after chronic HS feeding. Gut bacteria depletion by non-absorbable antibiotic administration restored HS loadinginduced gut leakiness, renal injury and systolic blood pressure elevation. The fecal microbiota from mice fed chronic HS could independently cause gut leakiness and renal injury. Our current work provides a novel insight into the mechanism of HS-induced renal injury by investigating the role of the intestine with enteric bacteria and gut permeability and clearly illustrates that chronic HS loading elicited renal injury and dysfunction that was dependent on the intestine.