72 research outputs found
Entropy Weight Measure Model of Online Influential Users’ Relative Social Capital
Based on the perspectives of information resource management and social capital measurement, this paper studies how influential users acquire, accumulate, and use their social capital in social networks to explore the general rules, which enterprises use influential users’ relative competitiveness in their topic areas of expertise to advertise precisely. The paper describes the social capital differences among influential users by introducing and calculating users’ relative social capital. Results show that user’s social capital values in different fields are dissimilar, and the scope and intensity of social capital among different users are relative. The proposed method is proved to be effective and reasonable
Information Entropy-based Social Capital Measure Method of Online Influential Users
Measuring online user influence is a major research topic in social marketing performance maximization. In this study, we comprehensively investigate how online influential users gain, accumulate, and use their social capital from the perspective of information resource management and social capital measurement. First, we define the social capital of online influential users and the attribute characters and relationships reflected fully by personality and sociality index data. We then construct a social capital measurement indicator system and information entropy model of online users. After the calculations of this model, we finally forma social capital measure method of online influential users. The rationality and validity of proposed model are tested by experimental study on real datasets
Epidermal growth factor receptor in breast carcinoma: association between gene copy number and mutations
<p>Abstract</p> <p>Background</p> <p>The epidermal growth factor receptor (EGFR) is an available target of effective anti-EGFR therapy for human breast cancer. The aim of this study was to assess the presence of EGFR gene amplification and mutations in breast cancer and to analyze the association between the statuses of these two gene alterations.</p> <p>Materials and methods</p> <p>EGFR gene amplification and mutations were investigated in formalin-fixed, paraffin-embedded tissues from 139 Chinese female patients with breast cancer by means of fluorescence in-situ hybridization (FISH) and fluorescently labeled real-time quantitative polymerase chain reaction (RT-PCR), respectively.</p> <p>Results</p> <p>EGFR gene amplification was observed in 46/139 (33.1%) of cases by FISH. Based on RT-PCR, 2/139 (1.4%) samples had EGFR gene mutations. Overall, only 1 (0.7%) of the cases was identified with both whole gene amplification and mutation, and 92 (66.2%) of cases were negative for both. High gene copy numbers of EGFR had significant correlation with the occurrence of EGFR protein expressions (P = 0.002).</p> <p>Conclusion</p> <p>In this study, EGFR mutations were presented in only two samples, indicating that EGFR mutations should not be employed in future trials with anti-EGFR therapies for breast cancer. However, EGFR whole gene amplification is frequently observed in patients with breast cancer. It will be of significant interest to investigate whether EGFR gene copy number is a suitable screening test for EGFR-targeted therapy for breast cancer.</p
Genome-wide analyses identify KLF4 as an important negative regulator in T-cell acute lymphoblastic leukemia through directly inhibiting T-cell associated genes
é 2015 Li et al. Background: Kruppel-like factor 4 (KLF4) induces tumorigenesis or suppresses tumor growth in a tissue-dependent manner. However, the roles of KLF4 in hematological malignancies and the mechanisms of action are not fully understood. Methods: Inducible KLF4-overexpression Jurkat cell line combined with mouse models bearing cell-derived xenografts and primary T-cell acute lymphoblastic leukemia (T-ALL) cells from four patients were used to assess the functional role of KLF4 in T-ALL cells in vitro and in vivo. A genome-wide RNA-seq analysis was conducted to identify genes regulated by KLF4 in T-ALL cells. Chromatin immunoprecipitation (ChIP) PCR was used to determine direct binding sites of KLF4 in T-ALL cells. Results: Here we reveal that KLF4 induced apoptosis through the BCL2/BCLXL pathway in human T-ALL cell lines and primary T-ALL specimens. In consistence, mice engrafted with KLF4-overexpressing T-ALL cells exhibited prolonged survival. Interestingly, the KLF4-induced apoptosis in T-ALL cells was compromised in xenografts but the invasion capacity of KLF4-expressing T-ALL cells to hosts was dramatically dampened. We found that KLF4 overexpression inhibited T cell-associated genes including NOTCH1, BCL11B, GATA3, and TCF7. Further mechanistic studies revealed that KLF4 directly bound to the promoters of NOTCH1, BCL2, and CXCR4 and suppressed their expression. Additionally, KLF4 induced SUMOylation and degradation of BCL11B. Conclusions: These results suggest that KLF4 as a major transcription factor that suppresses the expression of T-cell associated genes, thus inhibiting T-ALL progression.Link_to_subscribed_fulltex
An Underwater Image Enhancement Algorithm for Environment Recognition and Robot Navigation
There are many tasks that require clear and easily recognizable images in the field of underwater robotics and marine science, such as underwater target detection and identification of robot navigation and obstacle avoidance. However, water turbidity makes the underwater image quality too low to recognize. This paper proposes the use of the dark channel prior model for underwater environment recognition, in which underwater reflection models are used to obtain enhanced images. The proposed approach achieves very good performance and multi-scene robustness by combining the dark channel prior model with the underwater diffuse model. The experimental results are given to show the effectiveness of the dark channel prior model in underwater scenarios
Oxaliplatin-induced upregulation of exosomal miR-424-3p derived from human bone marrow mesenchymal stem cells attenuates progression of gastric cancer cells
Abstract Chemotherapy, particularly with oxaliplatin, is a key treatment for advanced gastric cancer (GC), and exosomes derived from human bone marrow mesenchymal stem cells (hBM-MSCs) play a vital role in the tumor microenvironment. The study aims to elucidate the previously unexplored role of exosomes derived from hBM-MSCs in GC tumorigenesis, especially under the influence of chemotherapy. We conducted an experimental study, utilizing miRNA sequencing and biological experiments, to analyze the tumorigenicity of exosomal miR-424-3p secreted by hBM-MSCs and its target gene RHOXF2 in GC cell lines. The results were confirmed through experimentation using a xenograft mouse model. This study demonstrated the role of hBM-MSCs in the GC microenvironment, focusing on their epithelial-mesenchymal transition (EMT) facilitation through exosomes, which led to enhanced tumorigenicity in GC cells. Intriguingly, this pro-tumor effect was abrogated when hBM-MSCs were treated with oxaliplatin. Exosomal miRNA sequencing revealed that oxaliplatin can upregulate the levels of miR-424-3p in exosomes secreted by hBM-MSCs, thereby inhibiting the EMT process in GC cells. Furthermore, miR-424-3p was identified to target and downregulate RHOXF2 expression, impeding the malignant behavior of GC cells both in vitro and in the mouse model. These findings uncover a potential hidden mechanism of oxaliplatin's anti-tumor action and propose the delivery of miR-424-3p via exosomes as a promising avenue for anti-tumor therapy
Impact of multi-hole-wall air coupling with air-staged technology on H2S evolution during pulverized coal combustion
The multi-hole-wall air coupling with air-staged technology (MH&AS) was developed for pulverized coal combustion to affect a simultaneous realization of multiple benefits, including prevention of high-temperature corrosion, highly efficient burning of pulverized coal, and low NOx emissions. In this work, the impact of MH&AS on H2S evolution under different conditions was investigated by applying a laboratory-scale MH&AS furnace to test its feasibility for preventing high-temperature corrosion. Some important inclusions were obtained: (i) the lack of multi-hole-wall air for Daheng (DH) coal combustion resulted in H2S concentration exceeding the critical value (namely, 100 ppm) causing high-temperature corrosion, but H2S near the wall could be completely eliminated with a multi-hole-wall air ratio (αm) of 0.1; (ii) the higher the pyrite content of the coal sample was or the smaller the particle size, the larger the H2S concentration near the wall; (iii) the four reactions leading to H2S formation were validated by Gibbs free energy and chemical equilibrium constant calculations. This study affirms the efficiency of MH&AS in mitigating the high-temperature associated with air-staged combustion
Comprehensive physiology and proteomics analysis revealed the resistance mechanism of rice (Oryza sativa L) to cadmium stress
Cadmium contamination can lead to a decrease in crop yield and quality. However, Cd-tolerant rice can improve rice resistance genes, improve crop tolerance to heavy metals, and protect plants from oxidative damage. In this study, Japonica rice: Chunyou 987 and Indica rice: Chuanzhong you 3607 were used to reveal the molecular response mechanism of Cd-tolerant rice under cadmium concentration of 3 mg/kg through comparative experiments combined with physiology and proteomics. The results showed that compared with indica rice, japonica rice showed more robust resistance to Cd stress and effectively retained many Cd ions in roots. Moreover, it enhanced its enzymatic and non-enzymatic anti-oxidative stress mechanism, which increased the activities of catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) by 47.37%, 21.75%, and 55.42%, respectively. The contents of non-enzymatic antioxidant substances ascorbic acid (AsA), glutathione (GSH), cysteine (Cys), proline (PRO), anthocyanins (OPC), and flavonoids were increased by 25.32%, 42.67%, 21.43%, 50.81%, 33.23%, and 72.16%, respectively. Through proteomics analysis, it was found that in response to the damage caused by cadmium stress, Japonica rice makes Photosynthesis functional proteins (psbO and PetH), Photosynthesis antenna proteins (LHCA and ASCAB9), Carbon fixation functional proteins (PEPC and OsAld), Porphyrin metabolism functional proteins (OsRCCR1 and SE5), Glyoxylate and dicarboxylate The expression of metabolism functional proteins (CATC and GLO4.) and Glutathione metabolism functional proteins (APX8 and OsGSTU13) were significantly up-regulated, which stimulated the antioxidant stress mechanism and photosynthetic system, and constructed a robust energy supply system to ensure the normal metabolic activities of life. Strengthening the mechanisms of plant homeostasis. In summary, this study revealed the molecular mechanism of tolerance to Cd stress in japonica rice, and the results of this study will provide a possible way to improve Cd-resistant rice seedlings
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