The role of cultural development in urban strategy: the Hub City of Asian Culture in Gwangju, Korea

This thesis investigates the role of cultural development in urban strategy. In particular, it reflects on the application of Western-developed theories and practices of cultural planning to culture-led urban developments in Asian cities. Through the case study of the Hub City of Asian Culture project in Gwangju, Korea by employing documentary analysis and supplementary semi-structured intervews, the thesis investigates cultural and urban policies, the background and process of the project delivery, the ways the project has affected change in the city, and future challenges for Gwangju. The thesis identifies four key characteristics of culture-led urban development projects: these are, the emergence of most large scale culture-led urban developments out of a longer history of culturally focused planning and policy, the centrality of city image change as a key driver, as well as the pursuit of economic impact, and the engagement of local communities as, at least, an important discourse in the development and implementation of such projects. The thesis uses its identification of these characteristics as a frame to examine the case of the Hub City of Asian Culture project. It was initially anticipated that this frame for understanding culture-led urban development projects would reveal the similarities of the Asian case with those Western cases which the frame was developed. In fact the investigation has revealed that the processes of project delivery in Gwangju have shown quite different aspects from the Western examples due to the city’s unique local context. Drawing particular attention to the ways in which the Hub City of Asian Culture has been implemented, and how it has tried to solve the challenges and opportunities that emerged from the local context, the research contributes to a wider discussion of culture-led urban strategy, and furthermore hopes to contribute to the developing discussion of culture-led development in Asia

Gold nanoparticle encoded with marigold (Tagetes erecta L.) suppressed hyperglycemia -induced senescence in retinal pigment epithelium via suppression of lipid peroxidation

This paper presents a simple and environmentally friendly method for synthesizing Tagetes erecta L. gold nanoparticles (TE-GNPs) using an aqueous extract of Tagetes erecta L. (TE). The TE extract serves as a reducing and stabilizing agent, and its antioxidant activity is evaluated using 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays. The TE extract exhibits significant DPPH and ABTS radical scavenging activities, indicating its strong antioxidative properties attributed to various antioxidant compounds. TE-GNPs are successfully synthesized by incubating the TE extract with a chloroauric acid solution, resulting in a color change from light yellow to ruby red. UV–Vis spectroscopy confirms the synthesis of TE-GNPs, evidenced by a characteristic absorption peak at approximately 524 nm, corresponding to the nanoparticles' surface plasmon resonance. Physicochemical characterization reveals that TE-GNPs possess nanoscale dimensions (28.9 ± 2.3 nm), stability (zeta potential of −31.5 ± 28), and a crystalline nature (validated via X-ray diffraction; XRD). Functional groups responsible for biosynthesis and stabilization are identified through Fourier transform infrared spectroscopy (FT-IR) analysis. high-resolution transmission electron microscopy (HR-TEM) images demonstrate the morphology, size, and dispersion of TE-GNPs, while selected area electron diffraction (SAED) patterns confirm their crystalline structures. Additionally, high-angle annular dark field (HAADF) imaging and energy-dispersive X-ray spectroscopy (EDX) spectroscopy verify the distribution and presence of gold in the TE-GNPs, respectively. Cytotoxicity assays confirm the biocompatibility of TE-GNPs. Furthermore, their potential in mitigating high glucose-induced cell death and oxidative stress in retinal pigment epithelial (RPE) cells is evaluated. Treatment with TE-GNPs restores the proliferation rate of RPE cells and reduces the proportion of apoptotic cells under high glucose conditions. TE-GNPs also decrease the high glucose-induced production of intracellular and mitochondrial reactive oxygen species. Markers of cellular senescence, including SA-β-galactosidase activity and lysosomal dysfunction, are attenuated by the TE-GNPs. Moreover, the TE-GNPs effectively reduce lipid accumulation and peroxidation in RPE cells exposed to high levels of glucose. These findings highlight the successful green synthesis of TE-GNPs using an aqueous extract of TE and underscore their desirable properties and anti-senescence effects

Green Synthesis of Silver and Gold Nanoparticles via <i>Sargassum serratifolium</i> Extract for Catalytic Reduction of Organic Dyes

The green synthesis of inorganic nanoparticles (NPs) using bio-materials has attained enormous attention in recent years due to its simple, eco-friendly, low-cost and non-toxic nature. In this work, silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) were synthesized by the marine algae extract, Sargassum serratifolium (SS). The characteristic studies of bio-synthesized SS-AgNPs and SS-AuNPs were carried out by using ultraviolet–visible (UV–Vis) absorption spectroscopy, dynamic light scattering (DLS), high-resolution transmission electron microscope (HR-TEM), selected area electron diffraction (SAED), energy-dispersive X-ray spectroscopy (EDX), X-ray powder diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). Phytochemicals in the algae extract, such as meroterpenoids, acted as a capping agent for the NPs’ growth. The synthesized Ag and Au NPs were found to have important catalytic activity for the degradation of organic dyes, including methylene blue, rhodamine B and methyl orange. The reduction of dyes by SS-AgNPs and -AuNPs followed the pseudo-first order kinetics

Cucurbitacin B-, E-, and I-Induced Browning of White Adipocytes Is Promoted by the Inhibition of Phospholipase D2

The mechanism of white adipose tissue browning is not well understood; however, naturally occurring compounds are known to play a positive role. The effects of cucurbitacins B, E, and I on the browning of mature white adipocytes were investigated. First, the cell viability exhibited by cucurbitacins B, E, and I in pre- and mature adipocytes was verified. Cucurbitacins B, E, and I had no effect on cell viability in pre- and mature adipocytes at concentrations up to 300 nM. To investigate the characteristics of representative beige adipocytes, the formation and morphology of cucurbitacin B, E, and I lipid droplets were verified. The total lipid droplet surface area, maximum Feret diameter, and total Nile red staining intensity of cucurbitacin B-, E-, and I-treated adipocytes were lower than those of mature white adipocytes. Furthermore, treatment of white mature adipocytes with cucurbitacin B, E, and I led to the formation of several small lipid droplets that are readily available for energy expenditure. We evaluated the effect of cucurbitacins B, E, and I on the expression of representative browning markers UCP1, PGC1a, and PRDM16, which participate in the browning of white adipose tissue. Cucurbitacins B, E, and I increased the mRNA and protein expression levels of UCP1, PGC1a, and PRDM16 in a concentration-dependent manner. To promote energy consumption by beige adipocytes, active mitochondrial biogenesis is essential. Next, we investigated the effects of cucurbitacin B, E, and I on mitochondrial biogenesis in mature adipocytes. Mitochondrial mass increased when mature adipocytes were treated with cucurbitacin B, E, and I. The degree of cucurbitacin B-, E- and I-induced transformation of white adipocytes into beige adipocytes was in the order of Cu E > Cu B > Cu I. To verify the effect of phospholipase D2 on the browning of white adipocytes, CAY10594—a PLD2 pharmacological inhibitor, and a knockdown system were used. PLD2 inhibition and knockdown improved the expression levels of UCP1, PGC1a, and PRDM16. In addition, PLD2 inhibition and knockdown in mature white adipocytes promoted mitochondrial biosynthesis. The effect of PLD2 inhibition and knockdown on promoting browning of white adipocytes significantly increased when Cu B, Cu E, and Cu I were co-treated. These data indicate that mature white adipocytes’ beige properties were induced by cucurbitacins B, E, and I. These effects became more potent by the inhibition of PLD2. These findings provide a model for determining anti-obesity agents that induce browning and increase energy expenditure in mature white adipocytes

A Comparative Study on Physicochemical, Photocatalytic, and Biological Properties of Silver Nanoparticles Formed Using Extracts of Different Parts of Cudrania tricuspidata

Green-synthesized silver nanoparticles (SNPs) have great potential for biomedical applications, due to their distinctive optical, chemical, and catalytic properties. In this study, we aimed to develop green-synthesized SNPs from extracts of Cudrania tricuspidata (CT) roots (CTR), stems (CTS), leaves (CTL), and fruit (CTF) and to evaluate their physicochemical, photocatalytic, and biological properties. CTR, CTS, CTL, and CTF extracts were evaluated and compared for their total phenol and flavonoid content, reducing capacity, and antioxidant activity. The results revealed that CTR, CTS, CTL, and CTF extracts have high phenol and flavonoid content, as well as a powerful antioxidant and reducing capacity. CTR and CTS extracts showed the strongest effects. The results from UV-Vis spectra analysis, dynamic light scattering, high-resolution transmission electron microscopy, energy dispersive spectroscopy, X-ray diffraction, and Fourier-transform infrared spectroscopy showed the successful formation of CT-SNPs with surface morphology, crystallinity, reduction capacity, capsulation, and stabilization. Synthesized CT-SNPs successfully photocatalyzed methylene blue, methyl orange, rhodamine B, and Reactive Black 5 within 20 min. The CTR- and CTS-SNPs showed better antibacterial properties against different pathogenic microbes (Staphylococcus aureus, Bacillus cereus, Escherichia coli, and Salmonella enteritidis) than the CTL- and CTF-SNPs. CTS- and CTR-SNPs showed the most effective cytotoxicity and antiapoptosis properties in human hepatocellular carcinoma cells (HepG2 and SK-Hep-1). CT-SNPs also seemed to be more biologically active than the CT extracts. The results of this study provide evidence of the establishment of CT extract SNPs and their physicochemical, photocatalytic, and biological properties

Experimental and Theoretical Analysis of Flexural Properties of Mortar Beam Reinforced with Coated Carbon-Fiber Textile

The flexural behavior of mortar beams reinforced with coated carbon-fiber textile was experimentally analyzed in this study. Accordingly, pull-out and bending tests were performed on textile-reinforced mortar (TRM) beam specimens. The experimental results demonstrated the superior bond performance of the coated carbon-fiber textile. The TRM beam exhibited sufficient ductility even after the occurrence of flexural cracks. In addition, a theoretical analysis method for predicting the flexural behavior of a TRM beam was established based on the experimentally determined bond behaviors of the textile reinforcement in cementitious materials. The analysis demonstrated that the bending behavior of the TRM beam was reasonably predicted. The results of this study can serve as basic data for the structural application of textile-reinforced cementitious composites

Characterization of <i>Plocamium telfairiae</i> Extract-Functionalized Au Nanostructures and Their Anti-Adipogenic Activity through PLD1

Here, Au nanostructure (AuNS) biosynthesis was mediated through ethanolic extract of Plocamium telfairiae (PT) without the use of stabilizers or surfactants. PT-functionalized AuNSs (PT-AuNSs) were analyzed using ultraviolet–visible spectroscopy, dynamic light scattering, high-resolution transmission electron microscopy, energy-dispersive spectroscopy, and Fourier-transform infrared spectroscopy. Stable monodisperse PT-AuNSs were synthesized, with a mean size of 15.36 ± 0.10 nm and zeta potential of −35.85 ± 1.36 mV. Moreover, biosynthetic AuNPs with a face-centered structure of PT-AuNS exhibited crystalline characteristics. In addition, many functional groups playing important roles in the biological reduction of PT extracts were adsorbed on the surface of PT-AuNSs. Furthermore, the effects of PT-AuNSs on adipogenesis in immature adipocytes were investigated. PT-AuNSs reduced morphological changes, lowered triglyceride content, and increased lipid accumulation by approximately 78.6% in immature adipocytes compared with the values in mature adipocytes (MDI-induced). PT-AuNS suppressed lipid accumulation by downregulating the transcript and protein expression of C/EBPα, PPARγ, SREBP 1, FAS, and aP2. Finally, PT-AuNS induced the transcript and protein expression of UCP1, PRDM16, and PGC1a, thereby increasing mitochondrial biogenesis in mature adipocytes and effectively inducing brown adipogenesis. In this study, the biosynthesized PT-AuNS was used as a potential therapeutic candidate because it conferred a potent anti-lipogenic effect. As a result, it can be used in various scientific fields such as medicine and the environment

Reducing Specific Contact Resistivity for n-type Germanium using Laser Activation Process and Nano-island Formation

This study presents a laser activation process (LAP) for germanium (Ge) to improve the electrical performance of n-type Ge devices. The LAP highly activated the dopant and created a shallow junction in Ge. We also investigated a triple contact of titanium (Ti)/nickel (Ni) nano-island/Ge to reduce contact resistivity and enhance the tunneling current. The results showed that the LAP with a fluence of 140 mJ/cm2 effectively activated the dopant, resulting in a high forward current density and a low ideality factor of the n+-p junction diode. The triple contact of Ti/Ni nano-island/Ge showed the lowest specific contact resistivity, indicating an increase in the tunneling current. The Ni nano-island contact showed the best overall electrical performance, attributed to the boosted electric field and the lower density of states at the interface. The results show that combining multiple approaches, including the optimized laser activation process and triple contact formation, can significantly reduce the contact resistance on n-type Ge, providing a promising approach for improving performance.TRU