Intelligent Model for the Compressibility Prediction of Cement-Stabilized Dredged Soil Based on Random Forest Regression Algorithm

Qianqian Guo,Bingyi Li,Yonghui Chen,Geng Chen,Long Chen 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.10

The determination of the compression characteristics of cement-stabilized dredged soil is an important issue. However, conventional method of laboratory compression test is time-consuming. Considering its robustness, random forest (RF) regression algorithm was utilized in this research to predict the compressibility of cement-stabilized dredge soil. The input variables included fundamental physical parameters of uncemented soil, water/cement ratio, and cement content. The output variables were initial void ratio e0 and compression index Csat the pre-yield state, which can be used to describe the compression curve. Furthermore, acomparative analysis between the RF and support vector machine (SVM) algorithms was implemented, and variable importance was also evaluated according to the RF model. Results indicate that the RF model could quickly predict Cs and e0 values of cement-stabilized dredged soil without one-dimensional oedometer tests. The RF algorithm was found to exhibit better performance than the SVM algorithm, and it has a strong ability to avoid over-fitting. The determination coefficient R2 for Cs and e0 on the validation set were found to respectively reach 0.83 and 0.97. Moreover, the importance values of the initial water content, water/cement ratio, and plastic limit were found to be 0.313, 0.249, and 0.117, respectively. The secant compression modulus Es1-2 obtained from the compression curves could be applied to the calculation of settlement and stress in engineering design.

Revisiting the Knoevenagel condensations: A universal and flexible bis-ammoniated fiber catalyst for the mild synthesis of α,β-unsaturated compounds

Qianqian Hu,Xian-Lei Shi,Yongju Chen,Xuefeng Han,Peigao Duan,Wenqin Zhang 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.54 No.-

A universal fiber catalyst for the Knoevenagel condensations is presented. The detailed characterization by mechanical properties, elemental analysis, FTIR spectroscopy, and SEM confirmed the rangeability of the fiber catalyst during the full-course. Moreover, the mediated condensations proceeded smoothly with lower catalyst amount (1 mol%) in different solvents of varying polarities and the products were obtained in good to excellent yields (95–99%), and even with water as the solvent could also achieve a series of a,b-unsaturated compounds with nearly quantitative yields at room temperature. Furthermore, the catalyst exhibited excellent flexibility and could be easily recovered and recycled with prominent stability over 10 cycles, and the procedure was operationally convenient and effectively amenable to the gram scale on a simple fixed-bed reactor.

Fiber-polyquaterniums@Cu(I) as recyclable polymer-supported copper complex catalysts for alkyne coupling and cycloaddition reactions

Qianqian Hu,Xian-Lei Shi,Yongju Chen,Feng Wang,Yujing Weng,Peigao Duan 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.69 No.-

Herein, a newly designed and synthesized fiber-supported polyquaterniums@Cu(I) served as efficient and recyclable polymer-supported copper complex catalysts for alkyne coupling and cycloaddition reactions, is reported. The fiber-supported copper complex catalyst was prepared systematically from commercially available polyacrylonitrile fiber, and characterized detailedly by elemental analysis, FTIR spectroscopy, mechanical properties, and SEM during both of the preparation and utilization processes. Moreover, the fiber-supported polyquaterniums@Cu(I) has been verified to possess high catalytic activities for the homocoupling of terminal alkyne in ethyl acetate (10 samples yields 83–99%, 10 cycles from 98% to 95%), A3 coupling of alkyne, aldehyde and amine in toluene (10 samples yields 81–94%, 10 cycles from 94% to 90%), and click chemistry of CuAAC reactions in water (10 samples yields 82–99%, 21 cycles from 97% to 96%). Furthermore, the newly developed fiber catalyst in spinning basket reactor displayed excellent stability and recyclability, and the concise and effective gram-scalable operation has extensive application prospect on chemical productions.

Risk factors affecting postoperative pulmonary function in congenital diaphragmatic hernia

Qianqian Wang,Quanhua Liu,Jingyu Zang,Jun Wang,Jie Chen 대한외과학회 2020 Annals of Surgical Treatment and Research(ASRT) Vol.98 No.4

Purpose: It is well known that congenital diaphragmatic hernia (CDH) in infants impacts pulmonary function rehabilitation after surgery. However, the risk factors of postoperative pulmonary function are still unclear. In this research, we analyzed the potential risk factors of postoperative pulmonary function in CDH patients in order to improve the clinical management of CDH patients. Methods: Thirty-three cases CDH infants followed were enrolled from November 2016 to September 2018. Clinical data were reviewed. Tidal breathing pulmonary function testing was performed after surgery. Correlation between pulmonary function and clinical characteristics was evaluated using multivariate analysis of variance. Results: Pulmonary dysfunction was detected in 87.9% patients (29 of 33). The defect size was found to be significantly larger in patients with obstructed and mixed ventilatory disorders (P = 0.001). Diagnosis of gestational age (GA) was also significantly earlier compared to restrictive ventilatory disorders (P = 0.001). Larger defect size, and earlier prenatal diagnosis of GA were detected in severe obstructive ventilatory disorders (P = 0.007, P = 0.001, retrospectively). Conclusion: Most patients had various degrees of pulmonary dysfunction after surgery. Patients with larger defect size and earlier diagnosis time might be vulnerable to severe obstructive and mixed ventilatory disorders.

Inhibition of chromosomal region maintenance 1 suppresses the migration and invasion of glioma cells via inactivation of the STAT3/MMP2 signaling pathway

Qianqian Shan,Shengsheng Li,Qiyu Cao,Chenglong Yue,Mingshan Niu,Xiangyu Chen,Lin Shi,Huan Li,Shangfeng Gao,Jun Liang,Rutong Yu,Xuejiao Liu 대한생리학회-대한약리학회 2020 The Korean Journal of Physiology & Pharmacology Vol.24 No.3

Chromosomal region maintenance 1 (CRM1) is associated with an adverse prognosis in glioma. We previously reported that CRM1 inhibition suppressed glioma cell proliferation both in vitro and in vivo. In this study, we investigated the role of CRM1 in the migration and invasion of glioma cells. S109, a novel reversible selective inhibitor of CRM1, was used to treat Human glioma U87 and U251 cells. Cell migration and invasion were evaluated by wound-healing and transwell invasion assays. The results showed that S109 significantly inhibited the migration and invasion of U87 and U251 cells. However, mutation of Cys528 in CRM1 abolished the inhibitory activity of S109 in glioma cells. Furthermore, we found that S109 treatment decreased the expression level and activity of MMP2 and reduced the level of phosphorylated STAT3 but not total STAT3. Therefore, the inhibition of migration and invasion induced by S109 may be associated with the downregulation of MMP2 activity and expression, and inactivation of the STAT3 signaling pathway. These results support our previous conclusion that inhibition of CRM1 is an attractive strategy for the treatment of glioma.

Fabrication of dual-coated graphene oxide nanosheets by polypyrrole and poly(ionic liquid) and their enhanced electrorheological responses

Chen, Panpan,Cheng, Qianqian,Wang, Li-Min,Liu, Ying Dan,Choi, Hyoung Jin Elsevier 2019 Journal of industrial and engineering chemistry Vol.69 No.-

<P><B>Abstract</B></P> <P>A two-dimensional composite material, poly(ionic liquid)-modified graphene oxide/polypyrrole (GO/PPy/PIL) multilayered nanosheets, was fabricated and applied as a new electrorheological (ER) material. The morphological differences between the single- and dual-coated nanosheets were confirmed using scanning electron microscopy and transmission electron microscopy. Rheological properties measured using a rotational rheometer indicated that the GO/PPy/PIL composite nanosheets exhibited relatively high ER effect under a certain electric field strength than the GO/PPy nanosheets because of the universal PIL second coating. The dual-coated nanosheets also showed a higher applicable electric field strength due to the semiconductive properties of the thick PIL layer.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Dual-coated composite GO/PPy/PIL nanosheets were fabricated. </LI> <LI> The PIL second coating significantly enhanced the ER effect of the nanosheets. </LI> <LI> GO/PPy/PIL exhibited higher available electric field strength than GO/PPy. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Numerical Simulation of the Coalescence Behavior of Intermittent Structures with Fissures

Qianqian Dong,Yulin Wu,Qiyang Chen 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.4

To further study the failure behavior of the rock-like materials containing intermittent fissures subjected to uniaxial compression, 3D printing technology was adopted to manufacture specimens with prefabricated kinked and straight fissures (K-S fissure). The order of average peak strength was -45o > -90o > +90o > +45o. The influence of different parameters, including the effective length and inclination angle of branch fissure, on the coalescence pattern was discussed. Results showed that two failure modes were observed: Model I represented tensile-shear composite failure in the rock bridge area, while Model II showed non-coalescence occurring. The effective length parameter presented a relatively larger influence than the inclination angle on the failure behavior. Additionally, Model I was discovered to tend to occur in the rock bridge region when the branch fissure turned anticlockwise. Based on numerical simulation using the Realistic Failure Process Analysis (RFPA2D), a quick damage criterion approach was proposed to estimate the coalescence behavior in the rock bridge, which was beneficial to determine coalescence pattern and failure behavior. Based on the curve fitted by the simulation, the coalescence pattern of cracks initiated from pre-existing intermittent fissures occurs in the tensile-shear composite fracture pattern, while non-coalescence occurs in the rock bridge below the curve.

Colonic Dysmotility in Murine Partial Colonic Obstruction Due to Functional Changes in Interstitial Cells

Qianqian Wang,Jingyu Zang,Xu Huang,Hongli Lu,Wenxie Xu,Jie Chen 대한소화기 기능성질환∙운동학회 2019 Journal of Neurogastroenterology and Motility (JNM Vol.25 No.4

Background/Aims Interstitial cells play important roles in gastrointestinal (GI) neuro-smooth muscle transmission. The underlying mechanisms of colonic dysmotility have not been well illustrated. We established a partial colon obstruction (PCO) mouse model to investigate the changes of interstitial cells and the correlation with colonic motility. Methods Western blot technique was employed to observe the protein expressions of Kit, platelet-derived growth factor receptor-α (Pdgfra), Ca2+-activated Cl− (Ano1) channels, and small conductance Ca2+- activated K+ (SK) channels. Colonic migrating motor complexes (CMMCs) and isometric force measurements were employed in control mice and PCO mice. Results PCO mice showed distended abdomen and feces excretion was significantly reduced. Anatomically, the colon above the obstructive silicone ring was obviously dilated. Kit and Ano1 proteins in the colonic smooth muscle layer of the PCO colons were significantly decreased, while the expression of Pdgfra and SK3 proteins were significantly increased. The effects of a nitric oxide synthase inhibitor (L-NAME) and an Ano1 channel inhibitor (NPPB) on CMMC and colonic spontaneous contractions were decreased in the proximal and distal colons of PCO mice. The SK agonist, CyPPA and antagonist, apamin in PCO mice showed more effect to the CMMCs and colonic smooth muscle contractions. Conclusions Colonic transit disorder may be due to the downregulation of the Kit and Ano1 channels and the upregulation of SK3 channels in platelet-derived growth factor receptor-α positive (PDGFRα+) cells. The imbalance between interstitial cells of Cajal-Ano1 and PDGFRα-SK3 distribution might be a potential reason for the colonic dysmotility. Background/Aims Interstitial cells play important roles in gastrointestinal (GI) neuro-smooth muscle transmission. The underlying mechanisms of colonic dysmotility have not been well illustrated. We established a partial colon obstruction (PCO) mouse model to investigate the changes of interstitial cells and the correlation with colonic motility. Methods Western blot technique was employed to observe the protein expressions of Kit, platelet-derived growth factor receptor-α (Pdgfra), Ca2+-activated Cl− (Ano1) channels, and small conductance Ca2+- activated K+ (SK) channels. Colonic migrating motor complexes (CMMCs) and isometric force measurements were employed in control mice and PCO mice. Results PCO mice showed distended abdomen and feces excretion was significantly reduced. Anatomically, the colon above the obstructive silicone ring was obviously dilated. Kit and Ano1 proteins in the colonic smooth muscle layer of the PCO colons were significantly decreased, while the expression of Pdgfra and SK3 proteins were significantly increased. The effects of a nitric oxide synthase inhibitor (L-NAME) and an Ano1 channel inhibitor (NPPB) on CMMC and colonic spontaneous contractions were decreased in the proximal and distal colons of PCO mice. The SK agonist, CyPPA and antagonist, apamin in PCO mice showed more effect to the CMMCs and colonic smooth muscle contractions. Conclusions Colonic transit disorder may be due to the downregulation of the Kit and Ano1 channels and the upregulation of SK3 channels in platelet-derived growth factor receptor-α positive (PDGFRα+) cells. The imbalance between interstitial cells of Cajal-Ano1 and PDGFRα-SK3 distribution might be a potential reason for the colonic dysmotility.

Epigenetically Modified Bone Marrow Stromal Cells in Silk Scaffolds Promote Craniofacial Bone Repair and Wound Healing

Han, Qianqian,Yang, Pishan,Wu, Yuwei,Meng, Shu,Sui, Lei,Zhang, Lan,Yu, Liming,Tang, Yin,Jiang, Hua,Xuan, Dongying,Kaplan, David L.,Kim, Sung Hoon,Tu, Qisheng,Chen, Jake Mary Ann Liebert 2015 Tissue engineering. Part A Vol.21 No.15

<P>Epigenetic regulation of gene expression is a central mechanism that governs cell stemness, determination, commitment, and differentiation. It has been recently found that PHF8, a major H4K20/H3K9 demethylase, plays a critical role in craniofacial and bone development. In this study, we hypothesize that PHF8 promotes osteoblastogenesis by epigenetically regulating the expression of a nuclear matrix protein, special AT-rich sequence-binding protein 2 (SATB2) that plays pivotal roles in skeletal patterning and osteoblast differentiation. Our results showed that expression levels of PHF8 and SATB2 in preosteoblasts and bone marrow stromal cells (BMSCs) increased simultaneously during osteogenic induction. Overexpressing PHF8 in these cells upregulated the expression of SATB2, Runx2, osterix, and bone matrix proteins. Conversely, knockdown of PHF8 reduced the expression of these genes. Furthermore, ChIP assays confirmed that PHF8 specifically bound to the transcription start site (TSS) of the SATB2 promoter, and the expression of H3K9me1 at the TSS region of SATB2 decreased in PHF8 overexpressed group. Implantation of the BMSCs overexpressing PHF8 with silk protein scaffolds promoted bone regeneration in critical-sized defects in mouse calvaria. Taken together, our results demonstrated that PHF8 epigenetically modulates SATB2 activity, triggering BMSCs osteogenic differentiation and facilitating bone formation and regeneration in biodegradable silk scaffolds.</P>

Study on the construction and demolition waste management policy in urban cities

( Shanping Chen ),( Bijun Xu ),( Jun Tai ),( Qianqian Tao ) 한국폐기물자원순환학회 2011 ISWA Vol.2011 No.0