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      • SCIESCOPUSKCI등재
      • SCIESCOPUSKCI등재

        Engineering of Biosynthesis Pathway and NADPH Supply for Improved L-5-Methyltetrahydrofolate Production by Lactococcus lactis

        ( Chuanchuan Lu ),( Yanfeng Liu ),( Jianghua Li ),( Long Liu ),( Guocheng Du ) 한국미생물생명공학회(구 한국산업미생물학회) 2021 Journal of microbiology and biotechnology Vol.31 No.1

        L-5-methyltetrahydrofolate (5-MTHF) is one of the biological active forms of folate, which is widely used as a nutraceutical. However, low yield and serious pollution associated with the chemical synthesis of 5-MTHF hampers its sustainable supply. In this study, 5-MTHF production was improved by engineering the 5-MTHF biosynthesis pathway and NADPH supply in Lactococcus lactis for developing a green and sustainable biosynthesis approach. Specifically, overexpressing the key rate-limiting enzyme methylenetetrahydrofolate reductase led to intracellular 5-MTHF accumulation, reaching 18 μg/l. Next, 5-MTHF synthesis was further enhanced by combinatorial overexpression of 5-MTHF synthesis pathway enzymes with methylenetetrahydrofolate reductase, resulting in 1.7-fold enhancement. The folate supply pathway was strengthened by expressing folE encoding GTP cyclohydrolase I, which increased 5-MTHF production 2.4-fold to 72 μg/l. Furthermore, glucose-6-phosphate dehydrogenase was overexpressed to improve the redox cofactor NADPH supply for 5- MTHF biosynthesis, which led to a 60% increase in intracellular NADPH and a 35% increase in 5-MTHF production (97 μg/l). To reduce formation of the by-product 5-formyltetrahydrofolate, overexpression of 5-formyltetrahydrofolate cyclo-ligase converted 5-formyltetrahydrofolate to 5,10-methyltetrahydrofolate, which enhanced the 5-MTHF titer to 132 μg/l. Finally, combinatorial addition of folate precursors to the fermentation medium boosted 5-MTHF production, reaching 300 μg/l. To the best of our knowledge, this titer is the highest achieved by L. lactis. This study lays the foundation for further engineering of L. lactis for efficient 5-MTHF biosynthesis.

      • SCIESCOPUS

        Experimental study of extracting artificial boundary condition frequencies for dynamic model updating

        Hou, Chuanchuan,Mao, Lei,Lu, Yong Techno-Press 2017 Smart Structures and Systems, An International Jou Vol.20 No.2

        In the field of dynamic measurement and structural damage identification, it is generally known that modal frequencies may be measured with higher accuracy than mode shapes. However, the number of natural frequencies within a measurable range is limited. Accessing additional forms of modal frequencies is thus desirable. The present study is concerned about the extraction of artificial boundary condition (ABC) frequencies from modal testing. The ABC frequencies correspond to the natural frequencies of the structure with a perturbed boundary condition, but they can be extracted from processing the frequency response functions (FRF) measured in a specific configuration from the structure in its existing state without the need of actually altering the physical support condition. This paper presents a comprehensive experimental investigation into the measurability of the ABC frequencies from physical experiments. It covers the testing procedure through modal testing, the data processing and data analysis requirements, and the FRF matrix operations leading to the extraction of the ABC frequencies. Specific sources of measurement errors and their effects on the accuracy of the extracted ABC frequencies are scrutinised. The extracted ABC frequencies are subsequently applied in the damage identification in beams by means of finite element model updating. Results demonstrate that it is possible to extract the first few ABC frequencies from the modal testing for a variety of artificial boundary conditions incorporating one or two virtual pin supports, and the inclusion of ABC frequencies enables the identification of structural damages without the need to involve the mode shape information.

      • KCI등재

        Fabrication of copper ions-substituted hydroxyapatite/polydopamine nanocomposites with high antibacterial and angiogenesis effects for promoting infected wound healing

        Bailong Tao,Chuanchuan Lin,Ai Guo,Yonglin Yu,Xian Qin,Kai Li,Hongchuan Tian,Weiwei Yi,Dengliang Lei,Lixue Chen 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.104 No.-

        Infected wound healing remains a critical threat, which frequently delays the healing process and evenleads to severe life-threatening complications. Herein, we reported an effective anti-infection approach,which was based on copper ions-releasing hydroxyapatite/polydopamine (HA-Cu/PDA) nanocompositeswith photothermal effect. The HA-Cu/PDA nanocomposites was fabricated through a co-precipitationreaction between polydopamine (PDA)-coated hydroxyapatite nanoparticles (HA)-loaded Cu2+ (HA-Cu). Through a synergistic effect of released Cu2+ and photothermal efficiency of PDA coating, and the HACu/PDA nanocomposites exhibited extraordinary antibacterial capacities against Escherichia coli (E. coli)and Staphylococcus aureus (S. aureus). The nanocomposites presented good biocompatibility for mouseembryonic fibroblast (NIH-3T3) cells and promoted NIH3T3 cells to migrate toward wound sites. Additionally, this nanocomposite could stimulate the tissue remodeling-related gene expression toinduce the blood vessels formation, granulation tissues and collagen deposition, and eventually enhancewound healing. In vivo study further verified that HA-Cu/PDA nanocomposites with NIR irradiation couldsignificantly improve bacterial infected wound healing through the prominent antibacterial property,reduced inflammatory response, the formation of granulation tissue, collagen deposition, and angiogenesisability. Thus, this study develops a versatile strategy for a broad range of wound healing and skinreconstruction caused by bacterial infection.

      • KCI등재

        Carbonation Model and Prediction of Polyvinyl Alcohol Fiber Concrete with Fiber Length and Content Effects

        Zuyun Luo,Xinhua Yang,Heli Ji,Chuanchuan Zhang 한국콘크리트학회 2022 International Journal of Concrete Structures and M Vol.16 No.2

        Durability is an important aspect of reliability of concrete structures. In order to establish the carbonation model of polyvinyl alcohol (PVA) fiber concrete including the influences of PVA fiber length and volume content, a series of accelerated carbonation experiments were carried out on the normal concrete specimens and PVA fiber concrete specimens with fiber lengths of 3 mm, 6 mm, 12 mm and 18 mm and fiber volume contents of 0.1%, 0.3%, 0.5%, 0.75%, 1.0% and 1.5%, respectively. The experimental conditions remained at temperature of 20 ℃, humidity of 70%, and carbon dioxide concentration of 20%. It was found that the addition of PVA fibers could improve the carbonation resistance of concrete considerably. Within the investigated range of fiber length and content, the carbonation resistance of concrete is first strengthened and then weakened with increasing PVA fiber length or content. The quadratic carbonation depth prediction model could characterize the influences of PVA fiber length and content better than the linear model. The carbon dioxide diffusion equation was established by introducing a PVA fiber influence factor and its parameters were determined from the carbonation depth prediction model. The carbonation process of PVA fiber concrete under the accelerated carbonation experiment condition was simulated. Both the model and the numerical method were validated by comparison between the experimental and numerical results. Finally, the influences of added PVA fibers on the carbonation life and durability of reinforced concrete components were further studied numerically. The results showed that compared with the normal concrete component, the durability of PVA fiber concrete components is significantly improved.

      • KCI등재

        One-Step Hydrothermal Preparation of 1D α-MoO3 Nanobelt Electrode Material for Supercapacitor

        Puhong Wen,Jingjing Guo,Lijun Ren,Chuanchuan Wang,Yuzhu Lan,Xiaowen Jiang 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.7

        1D α-MoO3 nanobelts were prepared using ammonium heptamolybdate tetrahydrate [(NH4)6Mo7O24 · 4H2O] as raw material by one-step hydrothermal method without template or guide agent at 180 ℃. The layered α-MoO3 nanobelt electrode has favorable electrochemical performance, and displays a fairly high specific capacitance, which can be up to 445 F/g at a current density of 0.5 A/g.

      • SCIESCOPUSKCI등재

        Low-dose of organic trace minerals reduced fecal mineral excretion without compromising performance of laying hens

        Qiu, Jialing,Lu, Xintao,Ma, Lianxiang,Hou, Chuanchuan,He, Junna,Liu, Bing,Yu, Dongyou,Lin, Gang,Xu, Jiming Asian Australasian Association of Animal Productio 2020 Animal Bioscience Vol.33 No.4

        Objective: The objective of this study was to investigate the effects of low doses of organic trace minerals (iron, copper, manganese, and zinc) on productive performance, egg quality, yolk and tissue mineral retention, and fecal mineral excretion of laying hens during the late laying period. Methods: A total of 405 healthy hens (HY-Line White, 50-week-old) were randomly divided into 3 treatments, with 9 replicates per treatment and 15 birds per replicate. The dietary treatments included feeding a basal diet + inorganic trace minerals at commercial levels (CON), a basal diet + inorganic trace minerals at 1/3 commercial levels (ITM), and a basal diet + proteinated trace minerals at 1/3 commercial levels (TRT). The trial lasted for 56 days. Results: Compared to CON, ITM decreased (p<0.05) egg production, daily egg mass, albumen height, eggshell strength, yolk Fe concentration, serum alkaline phosphatase activity and total protein, and increased (p<0.05) egg loss and feed to egg ratio. Whereas with productive performance, egg quality, yolk mineral retention, and serum indices there were no differences (p>0.05) between CON and TRT. The concentrations of Fe and Mn in the tissue and tibia were changed notably in ITM relative to CON and TRT. Both ITM and TRT reduced (p<0.05) fecal mineral excretion compared to CON. Conclusion: These results indicate that dietary supplementation of low-dose organic trace minerals reduced fecal mineral excretion without negatively impacting hen performance and egg quality.

      • SCIESCOPUSKCI등재

        Effects of low-dose organic trace minerals on performance, mineral status, and fecal mineral excretion of sows

        Ma, Lianxiang,He, Junna,Lu, Xintao,Qiu, Jialing,Hou, Chuanchuan,Liu, Bing,Lin, Gang,Yu, Dongyou Asian Australasian Association of Animal Productio 2020 Animal Bioscience Vol.33 No.1

        Objective: To investigate the effects of low-dose trace mineral proteinates on reproductive performance, mineral status, milk immunoglobulin contents and fecal mineral excretion of sows. Methods: Eighty crossbred sows (Landrace×Large White) were randomly allocated to two groups in a 135-day trail, from breeding through 21 d postpartum. The two treatments were inorganic trace minerals (ITM): a basal diet+inorganic iron (Fe), copper (Cu), manganese (Mn), and zinc (Zn) at 90, 15, 25 and 90 mg/kg, respectively and organic trace minerals (OTM): a basal diet+proteinates of Fe, Cu, Mn, and Zn at 72, 12, 20, and 72 mg/kg, respectively. Results: Compared with ITM, OTM significantly increased (p<0.05) the number of piglets with birthweight >1 kg, the litter weaning weight, and milk Fe, Cu contents. No significant differences (p>0.05) were observed on sow hair mineral contents or immunoglobulin M (IgM), IgG, and IgA contents in colostrum and milk. In comparsion to ITM, OTM decreased fecal Fe, Cu, Mn, and Zn contents of gestating sows (p<0.01) and Fe, Mn, and Zn in lactating sows (p<0.01). Conclusion: These results indicate that low-dose mineral proteinates can increase the number of piglets with birthweight >1 kg, the litter weaning weight and certain milk mineral concentrations while reducing fecal mineral excretion.

      • KCI등재

        Effects of compound organic acid calcium on growth performance, hepatic antioxidation and intestinal barrier of male broilers under heat stress

        He Junna,Ma Lianxiang,Qiu Jialing,Lu Xintao,Hou Chuanchuan,Liu Bing,Yu Dongyou 아세아·태평양축산학회 2020 Animal Bioscience Vol.33 No.7

        Objective: The aim of this study was to evaluate the effects of compound organic acid calcium (COAC) on growth performance, hepatic antioxidant status and intestinal barrier of male broilers under high ambient temperature (32.7°C). Methods: Nine hundred healthy one-d-old Cobb-500 male broiler chicks were randomly assigned into three groups with six replicates of 50 birds each. A basal diet supplemented with 0% (control), 0.4% and 0.8% COAC, respectively were fed to birds for 6 weeks. All treatments were under high ambient indoor temperature of 32.7°C, and had a constant calcium and available phosphorus ratio. Results: The results showed that, compared with control, the average daily gain of broilers in 0.4% and 0.8% was significantly increased and the ratio of feed to gain in in 0.4% and 0.8% was significantly decreased at 1 to 21, 22 to 42 and 1 to 42 days of age (p<0.05). Compared with control, 0.8% COAC slightly decreased (p = 0.093) the content of malondialdehyde in liver at 42 days of age while 0.4% COAC significantly decreased (p<0.05) the activity of alkaline phosphatase. Furthermore, 0.4% COAC significantly enhanced the intestinal barrier function via increasing jejunal and ileal ocln transcription, promoting jejunal mucin 2 transcription at 42 days of age (p<0.05), and decreasing jejunal toll-like receptor 2 (TLR-2) and ileal TLR-15, inducible nitric oxide synthase compared with control group (p<0.05). Whereas, no significant differences on the transcription of interleukin-1β in jejunum and ileum were observed among three treatments (p>0.05). Overall, heat stress caused by high natural environment temperature may induce the damage to hepatic antioxidation and intestinal barrier. Conclusion: Dietary inclusion of COAC can improve the tolerance of broilers to thermal environment through the modification of antioxidative parameters in liver and the mRNA expression of genes in intestinal barrier, resulting in an optimal inclusion level of 0.4%.

      • Crustal structure of the Gunsan Basin in the SE Yellow Sea from ocean bottom seismometer (OBS) data and its linkage to the South China Block

        Kim, Han-Joon,Kim, Chung-Ho,Hao, Tianyao,Liu, Lihua,Kim, Kwang-Hee,Jun, Hyunggu,Jou, Hyeong-Tae,Moon, Sunghoon,Xu, Ya,Wu, Zhiqiang,Lu, Chuanchuan,Lee, Sang Hoon Elsevier 2019 Journal of Asian earth sciences Vol.180 No.-

        <P><B>Abstract</B></P> <P>Two major tectonic units in NE Asia are the Sino-Korean (or North China) and South China Blocks that collided in the Permo-Triassic periods. The South China Block is suggested to extend eastward to the Korean Peninsula across the southern Yellow Sea. The Gunsan Basin is a well-defined, fault-bounded sedimentary basin in the SE Yellow Sea and is regarded as a structural link of the South China Block to the Korean Peninsula. We collected deep seismic sounding data recorded on ocean bottom seismometers to investigate how the crustal structure and nature of the South China Block vary in the Gunsan Basin toward the middle part of the Korean Peninsula. The main part of the Gunsan Basin is underlain by relatively thin (∼10 km thick) upper and much thicker (∼20 km thick) lower crustal layers, indicating a close affinity to the South China Block; whereas it shows distinction from the Korean Peninsula underlain by upper and lower crustal layers with equal (∼15 km) thickness. A change in crustal structure is recognized under the eastern margin of the Gunsan Basin toward the Korean Peninsula, that features a transition to the Korean Peninsula. The thick lower crustal layer in the Gunsan Basin appears to be inherited from the evolution of the South China Block including crustal shortening associated with the assembly of Rodinia in the Neoproterozoic before the collision between the Sino-Korean and South China Blocks.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We image how the crustal stucture nature vary in the SE Yellow Sea. </LI> <LI> The Gunsan Basin is underlain by relatively thin upper and much thick lower crustal layers. </LI> <LI> A transition in crustal structure is recognized from the South China Block to the Korean Peninsula. </LI> <LI> The crustal structure is inherited from the growth of Rodinia. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

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