135 research outputs found
Sustainable Transport Infrastructure and Economic Returns: A Bibliometric and Visualization Analysis
Sustainable transport infrastructure can determine the effect of countries&rsquo
transport-driven economic returns. Considering the economic, environmental, and social relevance and growing issues of CO 2 in the countries concerned, this study aims to examine sustainable transport infrastructure related to economic return through a bibliometric and visualization analysis from 2000 to 2019. First, to measure the status of sustainable transport infrastructure literature, we determine the number of publications produced per year. Second, we determine the most frequently cited articles and prominent journals on sustainable transport infrastructure. Third, we examine the co-occurrence of the author&rsquo
s keywords below the abstract. Fifth, we describe the bibliometric details in clusters and analyze the network link between reference, sources, and authors&rsquo
co-citations, and discuss the characteristics and structures of clusters. Sixth, we discuss the bibliographic relationship between authors, and finally, determine the country and the institutional network of co-authors. The obtained results identify that the most influential articles, journals, and authors that make a significant contribution to sustainable transport infrastructure studies and present the research sub-areas or themes related to sustainable transport infrastructure. Overall, the study found the paradigms of today, key research areas, and the link between the fields of sustainable transport infrastructure studies. In the meantime, this study also reveals the improvements in the main topics and sub-sections over the last 20 years and shows the changes in future areas of research. The study concluded that the findings could provide researchers with some insights and help to advance studies on sustainable transport systems.
Document type: Articl
Negative Group Velocity in the Absence of Absorption Resonance
Scientific community has well recognized that a Lorentzian medium exhibits anomalous dispersion behavior in its resonance absorption region. To satisfy the Krammers-Kronig relation, such an anomalous region has to be accompanied with significant loss, and thus, experimental observations of negative group velocity in this region generally require a gain-assisted approach. In this letter, we demonstrate that the negative group velocity can also be observed in the absence of absorption resonance. We show that the k-surface of a passive uniaxial Lorentzian medium undergoes a distortion near the plasma frequency. This process yields an anomalous dispersion bandwidth that is far away from the absorption resonance region, and enables the observation of negative group velocity at the plasma frequency band. Introducing anomalous dispersion in a well-controlled manner would greatly benefit the research of ultrafast photonics and find potential applications in optical delay lines, optical data storage and devices for quantum information processing
Pomolic acid inhibits proliferation of human lung carcinoma cells via induction of apoptosis and suppression of cell migration and invasion
Purpose: To investigate the anti-proliferative effect of pomolic acid on lung cancer cells (A549), and theunderlying mechanism.Methods: The viability of pomolic acid-treated A549 cells was determined by MTT and colony formation assays. Cell colony formation was monitored with acridine orange/ethidium bromide (AO/EB) staining. Protein expressions of Bax and Bcl-2 were assayed by western blotting.Results: Pomolic acid suppressed the growth of A549 cells, with an half-maximal inhibitory concentration of (IC50) of 10 ÎŒM (p < 0.05). However, the IC50 of pomolic acid for normal BEAS-2B cells was 80 ÎŒM. Pomolic acid also decreased colony formation of A549 cells. At 20 ÎŒM, the percentage of A549 colonies decreased to 14 % of control. The dose-dependent cytotoxicity of pomolic acid against A549 cells was mediated via induction of apoptosis and oxidative stress. Pomolic acid treatment enhanced the expression of Bax and decreased the expression of Bcl-2 in A549 cells. Moreover, pomolic acid inhibited the migration and invasion in A549 cells in a dose-dependent manner (p < 0.05).Conclusion: These results indicate the potent anticancer effect of pomolic acid against human lung cancer cells. Thus, pomolic acid has promising potential as a lead molecule for the development of chemotherapy
Screening and Identification of Hub Genes in the Development of Early Diabetic Kidney Disease Based on Weighted Gene Co-Expression Network Analysis
ObjectiveThe study aimed to screen key genes in early diabetic kidney disease (DKD) and predict their biological functions and signaling pathways using bioinformatics analysis of gene chips interrelated to early DKD in the Gene Expression Omnibus database.MethodsGene chip data for early DKD was obtained from the Gene Expression Omnibus expression profile database. We analyzed differentially expressed genes (DEGs) between patients with early DKD and healthy controls using the R language. For the screened DEGs, we predicted the biological functions and relevant signaling pathways by enrichment analysis of Gene Ontology (GO) biological functions and Kyoto Encyclopedia of Genes and Genomes (KEGG) signaling pathways. Using the STRING database and Cytoscape software, we constructed a protein interaction network to screen hub pathogenic genes. Finally, we performed immunohistochemistry on kidney specimens from the Beijing Hospital to verify the above findings.ResultsA total of 267 differential genes were obtained using GSE142025, namely, 176 upregulated and 91 downregulated genes. GO functional annotation enrichment analysis indicated that the DEGs were mainly involved in immune inflammatory response and cytokine effects. KEGG pathway analysis indicated that C-C receptor interactions and the IL-17 signaling pathway are essential for early DKD. We identified FOS, EGR1, ATF3, and JUN as hub sites of protein interactions using a proteinâprotein interaction network and module analysis. We performed immunohistochemistry (IHC) on five samples of early DKD and three normal samples from the Beijing Hospital to label the proteins. This demonstrated that FOS, EGR1, ATF3, and JUN in the early DKD group were significantly downregulated.ConclusionThe four hub genes FOS, EGR1, ATF3, and JUN were strongly associated with the infiltration of monocytes, M2 macrophages, and T regulatory cells in early DKD samples. We revealed that the expression of immune response or inflammatory genes was suppressed in early DKD. Meanwhile, the FOS group of low-expression genes showed that the activated biological functions included mRNA methylation, insulin receptor binding, and protein kinase A binding. These genes and pathways may serve as potential targets for treating early DKD
Structureâactivity relationship study of 2,4-diaminothiazoles as Cdk5/p25 kinase inhibitors
Cdk5/p25 has emerged as a principle therapeutic target for numerous acute and chronic neurodegenerative diseases, including Alzheimerâs disease. A structureâactivity relationship study of 2,4-diaminothiazole inhibitors revealed that increased Cdk5/p25 inhibitory activity could be accomplished by incorporating pyridines on the 2-amino group and addition of substituents to the 2- or 3-position of the phenyl ketone moiety. Interpretation of the SAR results for many of the analogs was aided through in silico docking with Cdk5/p25 and calculating protein hydrations sites using WaterMap. Finally, improved in vitro mouse microsomal stability was also achieved
Structureâactivity relationship study of EphB3 receptor tyrosine kinase inhibitors
A structureâactivity relationship study for a 2-chloroanilide derivative of pyrazolo[1,5-a]pyridine revealed that increased EphB3 kinase inhibitory activity could be accomplished by retaining the 2-chloroanilide and introducing a phenyl or small electron donating substituents to the 5-position of the pyrazolo[1,5-a]pyridine. In addition, replacement of the pyrazolo[1,5-a]pyridine with imidazo[1,2-a]pyridine was well tolerated and resulted in enhanced mouse liver microsome stability. The structureâactivity relationship for EphB3 inhibition of both heterocyclic series was similar. Kinase inhibitory activity was also demonstrated for representative analogs in cell culture. An analog (32, LDN-211904) was also profiled for inhibitory activity against a panel of 288 kinases and found to be quite selective for tyrosine kinases. Overall, these studies provide useful molecular probes for examining the in vitro, cellular and potentially in vivo kinase-dependent function of EphB3 receptor
Satellite Observed Positive Impacts of Fog on Vegetation
Fog is an important water source for many ecosystems, especially in drylands. Most fogâvegetation studies focus on individual plant scale; the relationship between fog and vegetation function at larger spatial scales remains unclear. This hinders an accurate prediction of climate change impacts on dryland ecosystems. To this end, we examined the effect of fog on vegetation utilizing both optical and microwave remote sensingâderived vegetation proxies and fog observations from two locations at Gobabeb and Marble Koppie within the fogâdominated zone of the Namib Desert. Significantly positive relationships were found between fog and vegetation attributes from optical data at both locations. The positive relationship was also observed for microwave data at Gobabeb. Fog can explain about 10%â30% of variability in vegetation proxies. These findings suggested that fog impacts on vegetation can be quantitatively evaluated from space using remote sensing data, opening a new window for research on fogâvegetation interactions
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