Enhanced Cutinase Production of Thermobifida fusca by a Two-stage Batch and Fed-batch Cultivation Strategy

Gangqiang He,Guanghua Huo,Liming Liu,Yang Zhu,Jian Chen,Guocheng Du 한국생물공학회 2009 Biotechnology and Bioprocess Engineering Vol.14 No.1

In this study, cutinase production by Thermobifida fusca WSH03-11 was investigated with mixed short-chain organic acids as co-carbon sources to demonstrate the possibility of producing high value-added products from organic wastes. T. fusca WSH03-11 was cultured with different combinations of butyrate, acetate, and lactate with a purpose of increasing cutinase activity. The optimum proportion of butyrate, acetate, and lactate was 4:1:3. In batch cultivation, acetate and lactate were consumed quickly, while the consumption of butyrate was depressed in the presence of acetate with a concentration higher than 0.5 g/L. Based on these results, a two-stage batch and fed-batch cultivation strategy was proposed: a batch culture with acetate and lactate as the co-carbon sources in the first 10 h, and then a fed-batch culture with a constant butyrate feeding rate of 12 mL/h during 11~20 h. By this two-stage cultivation strategy, cutinase activity, dry cell weight, and con-sumption rate of butyrate were increased by 70%, 103.4%, and 4.3-fold, respectively, compared to those of the batch cultivation. These results provided a novel and efficient way to produce high value-added products from organic wastes.

Group Effect of Dragload in Pile Groups Embedded in Consolidating Soil under Embankment Load

Gangqiang Kong,Yang Zhou,Qing Yang 대한토목학회 2016 KSCE JOURNAL OF CIVIL ENGINEERING Vol.20 No.6

In this paper, model tests and numerical simulations on 3 × 3 pile group embedded in consolidating soil under embankment load with different pile spacings are carried out. Single pile and 2 × 2 pile group are studied for comparative analyses. The performances of dragload versus relative displacement of pile-soil, load sequence and load rate, and the group effects of dragload and downdrag versus pile spacing are analyzed. A case study on dragload of a pile group considering with or without couple effect is also presented. It is worth pointing out that in this experimental condition, when pile-soil relative displacements reach 2 mm, dragload will reaches nearly 75-95% of the maximum values; When consolidation time reaches 240 h, the neutral plane becomes stable approximately at 0.95H (H is the thickness of compression soil). The dragload and downdrag are influenced by load sequence of pile head load versus surcharge load.

Ultimate Lateral Bearing Capacity and Group Effect of Belled Wedge Pile Groups

Gangqiang Kong,Huaifeng Peng,Hongyu Qin,Lehua Wang,Yongdong Meng 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.12

Pile foundation of ports, high-voltage transmission line tower are subjected to amount of lateral loading, prediction on lateral bearing capacity is one of the most important projects in structure design. This paper pertains to the model tests on pile-soil interaction of single pile, 2 × 1 and 2 × 2 belled wedge pile groups embedded in sand under lateral load. The load versus displacement, and the soil pressures along depth surrounding piles are measured, the ultimate lateral bearing capacities and group effects of belled wedge piles are analyzed and discussed. An simplified theoretical calculation method on predicting the lateral bearing capacities of shaped pile groups with considering group pile p-y curves, and longitudinal cross-section variation are proposed. The accuracy and reliability of this developed calculation method are verified through the comparative analysis with model test results obtained in this study and previous literature. The predicted values of lateral bearing capacities have suitable agreement with the measured data. It also shows that the ultimate lateral bearing capacities of belled wedge pile group are nearly 1.8 − 2.0 times of those of traditional belled pile with the same concrete usage in this study’s condition.

Enhancing visible-light-induced photocatalytic activity of BiOI microspheres for NO removal by synchronous coupling with Bi metal and graphene

Zhu, Gangqiang,Hojamberdiev, Mirabbos,Zhang, Shaolin,Din, Syed Taj Ud,Yang, Woochul Elsevier 2019 APPLIED SURFACE SCIENCE - Vol.467 No.-

<P><B>Abstract</B></P> <P>In order to further improve its photocatalytic activity, the BiOI microspheres were activated by a synchronous coupling of Bi metal and graphene under solvothermal conditions. The effects of the synthesis temperature (160–200 °C) on crystallinity, morphology, and photocatalytic activity were studied in particular. As expected, the ternary Bi-BiOI/graphene photocatalyst synthesized at 180 °C exhibited higher photocatalytic activity for NO oxidation removal under visible light irradiation than individual BiOI, and binary Bi-BiOI and BiOI/graphene composites. The photocatalytic efficiency for the NO removal of the ternary Bi-BiOI/graphene photocatalyst synthesized at 180 °C reached 51.8% within 30 min of visible light irradiation. The enhanced photocatalytic activity of the ternary Bi-BiOI/graphene photocatalyst is attributed to (I) the efficient transfer of photo-generated electrons from BiOI and Bi to graphene, leading to the effective separation of the photo-generated electron-hole pairs and (II) the surface plasmon resonance effect of Bi nanoparticles in the composite photocatalyst. Furthermore, the results of the scavenger experiments and DMPO-ESR spin-trapping measurements reveal that O<SUB>2</SUB> <SUP>−</SUP> radical species play the most critical role and holes serve as a secondary active species in the oxidative removal process of NO by 180BOI/GR composite under visible light irradiation.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Ternary Bi-BiOI/graphene photocatalyst was synthesized by solvothermal method. </LI> <LI> The composite photocatalyst can harness from visible to NIR spectrum. </LI> <LI> Bi-BiOI/graphene shows efficient photocatalytic activity for NO oxidation removal. </LI> <LI> O<SUB>2</SUB> <SUP>–</SUP> radical species play the most critical role in the photocatalytic process. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Mechanical Properties and Water Absorption of Alginate/hydroxypropyl Methyl Cellulose Blend Membranes with Semiinterpenetrating Network

Qianqian Wang,Gangqiang Zhang,Lin Zhang,Ping Zhu 한국섬유공학회 2020 Fibers and polymers Vol.21 No.7

Sodium alginate (SA) is a renewable material with broad application prospects in textiles, medicine, and otherfields. However, the disadvantage of poor strength and brittleness limited its future application. In this work, the SA wasreinforced by the hydroxypropyl methyl cellulose (HPMC) with a semi-interpenetrating network which leverages thefavourable properties. The structure and surface morphology of SA/HPMC blend membranes after Ca ion cross-linking wereexamined by FTIR, Raman, XRD and SEM. The mechanical properties and water absorbency of the blend membranes werealso studied. The results indicated that the hydrogen bond was found in SA/HPMC blend membranes, which improved theSA/HPMC blend membranes stability. Compared with calcium alginate membrane, the tensile strength and elongation atbreak of SA/HPMC blend membranes were improved to 57 % and 400 %, respectively.

Knockdown of lncRNA PVT1 Inhibits Vascular Smooth Muscle Cell Apoptosis and Extracellular Matrix Disruption in a Murine Abdominal Aortic Aneurysm Model

Zhidong Zhang,Gangqiang Zou,Xiaosan Chen,Wei Lu,Jianyang Liu,Shuiting Zhai,Gang Qiao 한국분자세포생물학회 2019 Molecules and cells Vol.42 No.3

This study was designed to determine the effects of the long non-coding RNA (lncRNA) plasmacytoma variant translocation 1 (PVT1) on vascular smooth muscle cell (VSMC) apoptosis and extracellular matrix (ECM) disruption in a murine abdominal aortic aneurysm (AAA) model. After injection of PVT1-silencing lentiviruses, AAA was induced in Apolipoprotein E-deficient (ApoE?/?) male mice by angiotensin II (Ang II) infusion for four weeks. After Ang II infusion, mouse serum levels of pro-inflammatory cytokines were analysed, and aortic tissues were isolated for histological, RNA, and protein analysis. Our results also showed that PVT1 expression was significantly upregulated in abdominal aortic tissues from AAA patients compared with that in controls. Additionally, Ang II treatment significantly increased PVT1 expression, both in cultured mouse VSMCs and in AAA murine abdominal aortic tissues. Of note, the effects of Ang II in facilitating cell apoptosis, increasing matrix metalloproteinase (MMP)-2 and MMP-9, reducing tissue inhibitor of MMP (TIMP)-1, and promoting switching from the contractile to synthetic phenotype in cultured VSMCs were enhanced by overexpression of PVT1 but attenuated by knockdown of PVT1. Furthermore, knockdown of PVT1 reversed Ang II-induced AAA-associated alterations in mice, as evidenced by attenuation of aortic diameter dilation, marked adventitial thickening, loss of elastin in the aorta, enhanced aortic cell apoptosis, elevated MMP-2 and MMP-9, reduced TIMP-1, and increased proinflammatory cytokines. In conclusion, our findings demonstrate that knockdown of lncRNA PVT1 suppresses VSMC apoptosis, ECM disruption, and serum pro-inflammatory cytokines in a murine Ang II-induced AAA model.

In Situ Formation of Leaf-Like Ag2S/CdS Heterojunction Photocatalyst Harnessing Vis-NIR Light for Photodegradation of Organic Pollutants

Chang, Libin,Zhu, Gangqiang,Lu, Huan,Hojamberdiev, Mirabbos,Zhang, Zengping,Gao, Jianzhi,Wang, Chenghui,Yang, Woochul Springer-Verlag 2018 Catalysis letters Vol.148 No.9

Knockdown of lncRNA PVT1 Inhibits Vascular Smooth Muscle Cell Apoptosis and Extracellular Matrix Disruption in a Murine Abdominal Aortic Aneurysm Model

Zhang, Zhidong,Zou, Gangqiang,Chen, Xiaosan,Lu, Wei,Liu, Jianyang,Zhai, Shuiting,Qiao, Gang Korean Society for Molecular and Cellular Biology 2019 Molecules and cells Vol.42 No.3

This study was designed to determine the effects of the long non-coding RNA (lncRNA) plasmacytoma variant translocation 1 (PVT1) on vascular smooth muscle cell (VSMC) apoptosis and extracellular matrix (ECM) disruption in a murine abdominal aortic aneurysm (AAA) model. After injection of PVT1-silencing lentiviruses, AAA was induced in Apolipoprotein E-deficient ($ApoE^{-/-}$) male mice by angiotensin II (Ang II) infusion for four weeks. After Ang II infusion, mouse serum levels of pro-inflammatory cytokines were analysed, and aortic tissues were isolated for histological, RNA, and protein analysis. Our results also showed that PVT1 expression was significantly upregulated in abdominal aortic tissues from AAA patients compared with that in controls. Additionally, Ang II treatment significantly increased PVT1 expression, both in cultured mouse VSMCs and in AAA murine abdominal aortic tissues. Of note, the effects of Ang II in facilitating cell apoptosis, increasing matrix metalloproteinase (MMP)-2 and MMP-9, reducing tissue inhibitor of MMP (TIMP)-1, and promoting switching from the contractile to synthetic phenotype in cultured VSMCs were enhanced by overexpression of PVT1 but attenuated by knockdown of PVT1. Furthermore, knockdown of PVT1 reversed Ang II-induced AAA-associated alterations in mice, as evidenced by attenuation of aortic diameter dilation, marked adventitial thickening, loss of elastin in the aorta, enhanced aortic cell apoptosis, elevated MMP-2 and MMP-9, reduced TIMP-1, and increased pro-inflammatory cytokines. In conclusion, our findings demonstrate that knockdown of lncRNA PVT1 suppresses VSMC apoptosis, ECM disruption, and serum pro-inflammatory cytokines in a murine Ang II-induced AAA model.

Experimental study on vacuum preloading with flocculation for solid-liquid separation in waste slurry

Wu, Yajun,Kong, Gangqiang,Lu, Yitian,Sun, De'an Techno-Press 2017 Geomechanics & engineering Vol.13 No.2

This vacuum preloading combined with polyacrylamide (PAM) flocculation was proposed to separating solid-liquid in waste slurry and to improving bearing capacity of soft soil ground. By using waste slurry taken from drilled shaft construction site in Shanghai, China, a series of settling column tests with four typical flocculants and one normal for waste slurry were carried out for comparative analysis. The optimal amounts for each flocculant were obtained from the column tests. Then, model tests on vacuum preloading with anionic polyacrylamide (APAM) flocculation and without flocculants were carried out. The out of water and the settlement of slurry surface ground were monitored during the model tests, and the changes in water content, particle-size and pore-size distributions in different positions after the model tests were measured and discussed. It is found that water content of the waste slurry without APAM flocculation changed from 204 to 195% by 24 hours standing and 15 hours vacuum preloading, while the water content of the waste slurry with APAM flocculation was declined from 163 to 96% by 24 hours standing, and was further reduced into 37% by 136 hours vacuum preloading, which shows that the combined method is feasible and effective.

Wave propagation in a concrete filled steel tubular column due to transient impact load

Xuanming Ding,Yuming Fan,Gangqiang Kong,Changjie Zheng 국제구조공학회 2014 Steel and Composite Structures, An International J Vol.17 No.6

This study aims to present a three dimensional finite element model to investigate the wave propagation in a concrete filled steel tubular column (CFSC) due to transient impact load. Both the concrete and steel are regarded as linear elastic material. The impact load is simulated by a semi sinusoidal impulse. Besides the CFSC models, a concrete column (CC) model is established for comparing under the same loading condition. The propagation characteristics of the transient waves in CFSC are analyzed in detail. The results show that at the intial stage of the wave propagation, the velocity waves in CFSC are almost the same as those in CC before they arrive at the steel tube. When the waves reach the column side, the velocity responses of CFSC are different from those of CC and the difference is more and more obvious as the waves travel down along the column shaft. The travel distance of the wave front in CFSC is farther than that in CC at the same time. For different wave speeds in steel and concrete material, the wave front in CFSC presents an arch shape, the apex of which locates at the center of the column. Differently, the wave front in CC presents a plane surface. Three dimensional effects on top of CFSC are obvious, therefore, the peak value and arrival time of incident wave crests have great difference at different locations in the radial direction. High-frequency waves on the waveforms are observed. The time difference between incident and reflected wave peaks decreases significantly with r/R when r/R < 0.6, however, it almost keeps constant when r/R ≥ 0.6. The time duration between incident and reflected waves calculated by 3D FEM is approximately equal to that calculated by 1D wave theory when r/R is about 2/3.