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  • 1
    Online Resource
    Online Resource
    Numerical Simulation of Rock Failure Process with a 3D Grain-Based Rock Model
    Hindawi Limited ; 2020
    In:  Advances in Civil Engineering Vol. 2020 ( 2020-07-31), p. 1-11
    Details
    In: Advances in Civil Engineering, Hindawi Limited, Vol. 2020 ( 2020-07-31), p. 1-11
    Abstract: A grain-based rock model was developed and applied to study mechanical characteristics and failure micromechanics in thick-walled cylinder and wellbore stability tests. The rock is represented as an assembly of tetrahedral blocks with bonded contacts. Material heterogeneity is modeled by varying the tensile strength at the block contacts. This grain-based rock model differs from previous disk/sphere particle-based rock models in its ability to represent a zero (or very low) initial porosity condition, as well as highly interlocked irregular block shapes that provide resistance to movement even after contact breakage. As a result, this model can reach higher uniaxial compressive strength to tensile strength ratios and larger friction coefficients than the disk/sphere particle-based rock model. The model captured the rock fragmentation process near the wellbore due to buckling and spalling. Thin fragments of rock similar to onion skins were produced, as observed in laboratory breakout experiments. The results suggest that this approach may be well suited to study the rock disaggregation process and other geomechanical problems in the rock excavation.
    Type of Medium: Online Resource
    ISSN: 1687-8086 , 1687-8094
    URL: Article
    DOI: 10.1155/2020/8810022
    Language: English
    Publisher: Hindawi Limited
    Publication Date: 2020
    detail.hit.zdb_id: 2449760-5
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  • 2
    Online Resource
    Online Resource
    Si3N4 Ceramic Ball Surface Defects’ Detection Based on SWT and Nonlinear Enhancement
    Hindawi Limited ; 2021
    In:  Mathematical Problems in Engineering Vol. 2021 ( 2021-9-13), p. 1-9
    Details
    In: Mathematical Problems in Engineering, Hindawi Limited, Vol. 2021 ( 2021-9-13), p. 1-9
    Abstract: In order to improve the detection accuracy and efficiency of silicon nitride ceramic ball surface defects, a defect detection algorithm based on SWT and nonlinear enhancement is proposed. In view of the small surface defect area and low contrast of the silicon nitride ceramic ball, a machine vision-based nondestructive inspection system for surface images is constructed. Sobel operation is used to eliminate the nonuniform background, and the silicon nitride ceramic ball surface image is decomposed by SWT. And frequency-domain index low-pass filtering is used to modify the decomposition coefficients, and an adaptive nonlinear model is proposed to enhance defects; finally, the image is reconstructed and segmented by the stationary wavelet inverse transform and the dynamic threshold method, respectively. The enhanced algorithm can effectively identify surface defects and is superior to traditional defect detection algorithms.
    Type of Medium: Online Resource
    ISSN: 1563-5147 , 1024-123X
    URL: Article
    DOI: 10.1155/2021/4922315
    Language: English
    Publisher: Hindawi Limited
    Publication Date: 2021
    detail.hit.zdb_id: 2014442-8
    SSG: 11
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  • 3
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    Online Resource
    Screening of Hub Genes in Hepatocellular Carcinoma Based on Network Analysis and Machine Learning
    Hindawi Limited ; 2022
    In:  Computational and Mathematical Methods in Medicine Vol. 2022 ( 2022-11-28), p. 1-32
    Details
    In: Computational and Mathematical Methods in Medicine, Hindawi Limited, Vol. 2022 ( 2022-11-28), p. 1-32
    Abstract: Hepatocellular carcinoma (LIHC) is the fifth common cancer worldwide, and it requires effective diagnosis and treatment to prevent aggressive metastasis. The purpose of this study was to construct a machine learning-based diagnostic model for the diagnosis of liver cancer. Using weighted correlation network analysis (WGCNA), univariate analysis, and Lasso-Cox regression analysis, protein-protein interactions network analysis is used to construct gene networks from transcriptome data of hepatocellular carcinoma patients and find hub genes for machine learning. The five models, including gradient boosting, random forest, support vector machine, logistic regression, and integrated learning, were to identify a multigene prediction model of patients. Immunological assessment, TP53 gene mutation and promoter methylation level analysis, and KEGG pathway analysis were performed on these groups. Potential drug molecular targets for the corresponding hepatocellular carcinomas were obtained by molecular docking for analysis, resulting in the screening of 2 modules that may be relevant to the survival of hepatocellular carcinoma patients, and the construction of 5 diagnostic models and multiple interaction networks. The modes of action of drug-molecule interactions that may be effective against hepatocellular carcinoma core genes CCNA2, CCNB1, and CDK1 were investigated. This study is expected to provide research ideas for early diagnosis of hepatocellular carcinoma.
    Type of Medium: Online Resource
    ISSN: 1748-6718 , 1748-670X
    URL: Article
    DOI: 10.1155/2022/7300788
    Language: English
    Publisher: Hindawi Limited
    Publication Date: 2022
    detail.hit.zdb_id: 2256917-0
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  • 4
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    Online Resource
    Effect of F11R Gene Knockdown on Malignant Biological Behaviors of Pancreatic Cancer Cells
    Hindawi Limited ; 2022
    In:  Journal of Oncology Vol. 2022 ( 2022-3-7), p. 1-8
    Details
    In: Journal of Oncology, Hindawi Limited, Vol. 2022 ( 2022-3-7), p. 1-8
    Abstract: F11R receptor (F11R/junctional adhesion molecule-A/F11R-A) is preferentially concentrated at tight junctions and influences epithelial cell morphology and migration. Numerous studies have shown that the aberrant expression of F11R contributes to tumor progression including pancreatic cancer. However, the significance of F11R in various tumors is controversial, and the role of F11R in regulating the malignant behaviors of human pancreatic cancer is unknown. To investigate the role of F11R in the carcinogenesis of pancreatic cancer and the potential targets of F11R as a therapeutic target for pancreatic cancer, we knocked down F11R in the pancreatic cancer cell line PANC-1 using lentiviral approaches. We found that F11R silencing led to decreased cell proliferation, a loss of cell invasiveness, cell cycle arrest in the G1 phase, and enhanced cell apoptosis. The present results suggest that F11R may be a promising therapeutic target for pancreatic cancer.
    Type of Medium: Online Resource
    ISSN: 1687-8469 , 1687-8450
    URL: Article
    DOI: 10.1155/2022/3379027
    Language: English
    Publisher: Hindawi Limited
    Publication Date: 2022
    detail.hit.zdb_id: 2461349-6
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  • 5
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    Nucleolin Promotes Cisplatin Resistance in Cervical Cancer by the YB1-MDR1 Pathway
    Hindawi Limited ; 2021
    In:  Journal of Oncology Vol. 2021 ( 2021-4-21), p. 1-11
    Details
    In: Journal of Oncology, Hindawi Limited, Vol. 2021 ( 2021-4-21), p. 1-11
    Abstract: Purpose. Cervical cancer is the fourth most common cancer in women worldwide and is the main cause of cancer-related deaths in women. Cisplatin (DDP) is one of the major chemotherapeutic drugs for cervical cancer patients. But, drug resistance limits the effectiveness of cancer therapy. Nucleolin (NCL) is a nucleocytoplasmic multifunctional protein involved in the development of cancer. It has been reported that NCL may be a potential target for modulation of drug resistance. However, the precise molecular mechanisms are poorly understood. Materials and Methods. Human cervical cancer Hela cells and their cisplatin-resistant cell line Hela/DDP were used in this study. The protein level of NCL in cervical cancer cells was measured by western blot analysis. Hela cells and Hela/DDP cells were transfected with NCL overexpression plasmid or NCL siRNA separately. MTT and EdU assay were performed to evaluate the cell viability and sensitivity to cisplatin. The drug efflux function of MDR1 protein was assessed by intracellular rhodamine-123 accumulation assay.The promoter activity of MDR1 was assessed by using a dual-luciferase reporter assay. Results. We found that the protein level of NCL was elevated in Hela/DDP cells. Overexpression of NCL increased cervical cancer cell proliferation and attenuated the sensitivity to cisplatin. Overexpression of NCL increased Multidrug resistance (MDR1) gene expression and drug efflux. Our results demonstrated that NCL was highly related with cisplatin resistance in cervical cancer. NCL played an important role in MDR1 gene transcription through regulation of the transcription factor YB1. Conclusion. Our findings revealed the novel role of NCL in cisplatin-resistant cervical cancer and NCL may be a potential therapeutic target for chemoresistance.
    Type of Medium: Online Resource
    ISSN: 1687-8469 , 1687-8450
    URL: Article
    DOI: 10.1155/2021/9992218
    Language: English
    Publisher: Hindawi Limited
    Publication Date: 2021
    detail.hit.zdb_id: 2461349-6
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  • 6
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    Palbociclib Enhances Migration and Invasion of Cancer Cells via Senescence-Associated Secretory Phenotype-Related CCL5 in Non-Small-Cell Lung Cancer
    Hindawi Limited ; 2022
    In:  Journal of Oncology Vol. 2022 ( 2022-9-27), p. 1-14
    Details
    In: Journal of Oncology, Hindawi Limited, Vol. 2022 ( 2022-9-27), p. 1-14
    Abstract: Palbociclib is the first CDK4/6 inhibitor approved by FDA and has been studied in many types of cancer. However, some studies showed that it could induce epithelial-mesenchymal transition (EMT) of cancer cells. To test the effect of palbociclib on non-small-cell lung cancer (NSCLC) cells, we treated NSCLC cells with different concentrations of palbociclib and detected its effects via MTT, migration and invasion assays, and apoptosis test. Further RNA sequencing was performed in the cells treated with 2 μM palbociclib or control. And Gene Ontology, Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Set Enrichment Analysis (GSEA), and protein-protein interaction network (PPI) were analyzed to explore the mechanism of palbociclib. The results showed that palbociclib significantly inhibited the growth of NSCLC cells and promoted apoptosis of cells, however, enhanced the migration and invasion abilities of cancer cells. RNA sequencing showed that cell cycle, inflammation-/immunity-related signaling, cytokine-cytokine receptor interaction, and cell senescence pathways were involved in the process, and CCL5 was one of the significantly differential genes affected by palbociclib. Further experiments showed that blocking CCL5-related pathways could reverse the malignant phenotype induced by palbociclib. Our results revealed that palbociclib-induced invasion and migration might be due to senescence-associated secretory phenotype (SASP) rather than EMT and suggested that SASP could act as a potential target to potentiate the antitumor effects of palbociclib in cancer treatment.
    Type of Medium: Online Resource
    ISSN: 1687-8469 , 1687-8450
    URL: Article
    DOI: 10.1155/2022/2260625
    Language: English
    Publisher: Hindawi Limited
    Publication Date: 2022
    detail.hit.zdb_id: 2461349-6
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  • 7
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    Online Resource
    Effect of the Double-Line Spiral Tunnel Curvature on the Tunnel Construction Stability
    Hindawi Limited ; 2020
    In:  Advances in Civil Engineering Vol. 2020 ( 2020-12-16), p. 1-9
    Details
    In: Advances in Civil Engineering, Hindawi Limited, Vol. 2020 ( 2020-12-16), p. 1-9
    Abstract: In the construction of mountain highway, in order to avoid complicated geology and adapt to the requirements of the terrain of the large height difference and the large slope, the double-line spiral tunnels are gradually applied. The purpose of this paper is to analyze the mechanical behavior of the double-line spiral tunnel and its surrounding rock under different line curvatures, and to obtain the influence of the curvature of the spiral tunnel on the stability of the double-line tunnel construction. The analysis of this paper is based on the engineering background of double-line spiral tunnels in China’s Yunnan province. The elastoplastic three-dimensional rock strata-tunnel by means of finite difference FLAC3D software was established to simulate the construction process. The model was verified by comparing the calculation results and the actual monitoring data of tunnel vault settlement. The small curvature radius spiral makes the mechanical behavior of the double-line tunnel uneven and the surrounding rock deformed unevenly. A quantitative analysis and qualitative evaluation of the influence of curvature radius were established by the systematic evaluation index of (1) ratio of compressive stress on both sides of the tunnel, (2) stress ratio of double-line tunnel, (3) convergent deformation of the cross section of the tunnel, and (4) deformation of the surrounding rock on the top of the tunnel. The results show that the small curvature radius (less than 200 m) will make the inner pressure of the inner tunnel significantly greater than the external pressure stress, showing obvious asymmetry, and the inner tunnel vault tensile stress is greater than the outer tunnel. With the increase of the curvature radius (about more than 400 m), the ratio of the compressive stress on the inside and outside of the tunnel tends to be constant, and the bias condition is weakened and stabilized. Meanwhile, the smaller curvature radius makes the convergent deformation of the cross section of the tunnel appear asymmetrical, and the compression quantity inside the tunnel center line is larger. It provides a reference basis for the stability control of the construction of the double-line spiral tunnels in the mountainous area.
    Type of Medium: Online Resource
    ISSN: 1687-8094 , 1687-8086
    URL: Article
    DOI: 10.1155/2020/8827806
    Language: English
    Publisher: Hindawi Limited
    Publication Date: 2020
    detail.hit.zdb_id: 2449760-5
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  • 8
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    Online Resource
    Plasma DNA Integrity as a Prognostic Biomarker for Colorectal Cancer Chemotherapy
    Hindawi Limited ; 2021
    In:  Journal of Oncology Vol. 2021 ( 2021-5-26), p. 1-10
    Details
    In: Journal of Oncology, Hindawi Limited, Vol. 2021 ( 2021-5-26), p. 1-10
    Abstract: Objectives. To verify whether the concentrations and integrity index of circulating cell-free DNA (cfDNA) in serum may be clinically useful for the progression monitoring of colorectal cancer (CRC) patients. Methods. Serum samples were collected from 76 primary CRC patients who underwent surgery, including 60 with chemotherapy and 43 with follow-up. Long (247 bp) and short (115 bp) DNA fragments in serum were detected by real-time quantitative PCR by amplifying the ALU repeats. Ten serum traditional biomarkers levels were detected by chemiluminescence immunoassay assay. Results. The median DNA integrity index (ALU247/ALU115) of serum DNA in the preoperative group was significantly higher than those in the postchemotherapy and the follow-up groups, while cfDNA concentration (ALU115) was significantly lower in the preoperative group compared with the postchemotherapy and the follow-up groups. CEA and CA242 were significantly lower in the postoperative group than in the preoperative group. Conclusions. Serum DNA integrity index (ALU247/115) may prove to be a promising candidate biomarker for prognostic prediction of CRC who underwent chemotherapy and during short-term follow-up.
    Type of Medium: Online Resource
    ISSN: 1687-8469 , 1687-8450
    URL: Article
    DOI: 10.1155/2021/5569783
    Language: English
    Publisher: Hindawi Limited
    Publication Date: 2021
    detail.hit.zdb_id: 2461349-6
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  • 9
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    Online Resource
    Competing Deactivation Channels for Excited π -Stacked Cytosines
    Hindawi Limited ; 2014
    In:  International Journal of Photoenergy Vol. 2014 ( 2014), p. 1-9
    Details
    In: International Journal of Photoenergy, Hindawi Limited, Vol. 2014 ( 2014), p. 1-9
    Abstract: The deactivation of π -stacked cytosine molecules following excitation by ultrashort laser pulses was studied using semiclassical dynamics simulations. Another deactivation channel was found to compete with a previously reported path that led to dimerization. For both pathways, the initial excited state was found to form a charge-separated neutral exciton state, which forms an excimer state by charge transfer. When the interbase distance becomes less than 3 Å, charge recombination occurs due to strong intermolecular interaction, ultimately leading to an avoided crossing. Results indicate that the C 2 –N 1 –C 6 –C 5 and C 2 ′ – N 1 ′ – C 6 ′ – C 5 ′ dihedral angles play a significant role in the vibronic coupling between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO). Vibrational energy distribution determines the fate of the excimer at the avoided crossing. Higher-amplitude vibration of C 5 or C 6 atoms leads to a nonadiabatic transition to the electronic ground state (a photophysical pathway); otherwise, a chemical reaction leading to the formation of cyclobutane type dimer occurs as found in earlier studies. The S 1 and S 0 potential energy surfaces calculated at TD-DFT level and the simulated trajectories were found to be consistent with CASPT2 results.
    Type of Medium: Online Resource
    ISSN: 1110-662X , 1687-529X
    URL: Article
    DOI: 10.1155/2014/158523
    Language: English
    Publisher: Hindawi Limited
    Publication Date: 2014
    detail.hit.zdb_id: 2028941-8
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  • 10
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    Online Resource
    Hydromechanical Simulation of Tunnel Excavation in Rock Considering a Nearby Karst Cave
    Hindawi Limited ; 2021
    In:  Mathematical Problems in Engineering Vol. 2021 ( 2021-12-18), p. 1-13
    Details
    In: Mathematical Problems in Engineering, Hindawi Limited, Vol. 2021 ( 2021-12-18), p. 1-13
    Abstract: Tunnel excavation tends to be affected by karst cavities in karst areas. Some cavities that are at low risk of causing safety issues without treatment tend to be ignored in the design and construction of tunnels to reduce costs. It is necessary to gain a better understanding of the effect of such a cavity on the seepage around a tunnel, the deformation of the surrounding rock, and the stress of the tunnel lining. In this paper, a two-dimensional rock-tunnel hydromechanical model with a karst cave was established with FLAC3D finite difference software to simulate the tunnel excavation with the consideration of seepage. Numerical simulations were performed to analyze the deformation of the surrounding rock, the seepage field of the surrounding rock, and the stress of the tunnel lining, and the results were compared for scenarios when the karst cave is at different locations relative to the tunnel. These results can provide a reference for the design and construction of tunnel engineering in rock with karst caves.
    Type of Medium: Online Resource
    ISSN: 1563-5147 , 1024-123X
    URL: Article
    DOI: 10.1155/2021/7875725
    Language: English
    Publisher: Hindawi Limited
    Publication Date: 2021
    detail.hit.zdb_id: 2014442-8
    SSG: 11
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