Effects of platelet-rich plasma on human gingival fibroblast proliferation and migration in vitro

Objective: This study evaluated the influence of platelet-rich plasma (PRP) on the behaviour of human gingival fibroblasts (hGFs), including fibroblast proliferation, migration and colony formation. Methods: PRP was obtained from the human peripheral blood of a healthy volunteer and then was diluted into platelet concentrations of 1%, 2% and 5%. The proliferation of hGFs was determined by two methods: (1) Cell-number counting with a haemocytometer method at days 1, 3, 5 and 7; (2) Colony-forming unit-fibroblast (CFU-F) assay at 2 weeks. The migration of hGFs was evaluated with scratch assay, then recorded digital images were analysed by Image-Analysis J 1.51j8 software to compare the remaining artificial wound areas between PRP groups at 0, 24 and 48 hours. Results: All hGFs that were cultivated in media with 1%, 2% and 5% PRP showed their ability to proliferate and migrate. Cell numbers incubated with 1% PRP increased significantly during the first three days and peaked at day 5, tending to be similar to their proliferation in complete medium. With concentrations of 2% and 5% PRP, hGFs outgrew and peaked at day 3, which was faster than with those in medium with 1% PRP. Especially, hGFs in the group 5% PRP proliferated with higher cell numbers than those in the other remaining groups at day 3. The hGF colony number that was formed in the group 5% PRP was significantly higher than those in the groups 1% and 2% PRP. Scratch assay showed hGFs in the groups 2% and 5% PRP almost filled the artificial wound and migrated more effectively than in the group 1% PRP at 24 hours, which was significant. Conclusion:In this study, perhaps the medium with 5% PRP is the dominant option, promoting the abilities of hGFs to heal wounds, because of its fast and effective impact on cell proliferation, colony formation and migration

Dynamic Relationship Between Residential Prices and Stock Prices in New Zealand

The purpose of this dissertation is to examine the relationship between house prices and stock prices in New Zealand, using quarterly data from 1990 to 2016. Employing Cointegration and Granger Causality tests, Variance Decomposition and Impulse Response Function, this study finds that while the two markets are generally segmented, there is some weak evidence showing that house prices lead stock prices in short-term and stock prices lead the house prices over long-run

Optimization of Design Procedure for Column-base Connections according to EN 1993-1-8:2006

The stiffness and the strength of a column-base connection have significant impacts on the behavior of a steel frame. The paper develops an interaction curve between moment and axial force for the column-base connections according to EN 1993-1-8:2006 with the variation of the base plate thickness and the bolt diameter. This is the fundamental base to determine the ultimate strength of a column-base plate that allows the designers to estimate the strength of column-base connections. This research investigates the relationship between the base plate thickness, the bolt diameter, and the moment strength of the column-base plate with a specific axial force to select an optimum solution. Also, the initial rotational stiffness is determined under a specific axial load and varied moments that satisfy the ultimate limit state. The relationship between moment–rotation is subsequently performed with the variation of the base plate thickness or the bolt diameter. The design procedure is proposed based on moment-axial force interaction curves and moment-rotation curves. This allows for optimizing the column-base connection from proper selections of base plate dimensions and bolt diameters

Study on Method of Doping Au Nanoparticles on ZnO Stratified Microstructure to Enhance Photocatalytic Ability and Antibacterial Activity

In this study, stratified microstructure gold/zinc oxide (Au/ZnO) composites were successfully prepared by the method of dispersing Au nanoparticles (Au NPs) on the surface of the hierarchical flower ZnO via HAuCl4 reduction in the presence of different reducing agents such as sodium citrate (SC), sodium borohydride (SB), sodium hydroxide and ethanol (SE), and Hg lamp 250W. Au-doped samples were named Au/ZnO-SC, Au/ZnO-SB, Au/ZnO-SE, and Au/ZnO-Hg lamp, respectively. Au/ZnO-SC and Au/ZnO-SB revealed the uniform distribution of Au nanoparticles on the ZnO substrate, meanwhile, Au nanoparticles were very densely distributed in Au/ZnO-SE and Au/ZnO-Hg lamp samples. The pure ZnO only showed an absorption peak in the ultraviolet (UV) region, Au/ZnO samples indicated additional absorption peaks in the visible light region (500-600 nm), which were characteristic of the surface plasmon resonance (SPR) effect of Au NPs in composites. Therefore, their bandgap energy was reduced compared to ZnO (3.202 eV), leading to increased photocatalytic efficiency under visible light irradiation. Among the doped samples, Au/ZnO-SC (with Au content as 5 wt%) had the largest surface area (26.23 m2/g) and the highest pore volume (0.263 cm3/g) and average pore width (33.2 nm). As a result, it showed the highest catalytic efficiency through complete degradation of tartrazine (TA) within 30 min with a reaction rate of 0.124 min−1 under Hg lamp 250 irradiation. In addition, both pure ZnO and Au/ZnO nanocomposites exhibited high antimicrobial activity in killing Escherichia coli (E. coli), and their enhancing effect of them was reliant on the weight ratio of Au on ZnO and the concentration of tested samples. These results indicated that Au/ZnO material has prominent potential for applications in water environment treatment. Copyright © 2023 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)

An improved performance routing protocol based on delay for MANETs in smart cities

Mobile ad-hoc networks (MANETs) is a set of mobile devices that can self-configuration, self-established parameters to transmission in-network. Although limited inability, MANETs have been applied in many domains to serve humanity in recent years, such as disaster recovery, forest fire, military, intelligent traffic, or IoT ecosystems. Because of the movement of network devices, the system performance is low. In order to MANETs could more contribution in the future of the Internet, the routing is a significant problem to enhance the performance of MANETs. In this work, we proposed a new delay-based protocol aim enhance the system performance, called performance routing protocol based on delay (PRPD). In order to analyze the efficiency of the proposed solution, we compared the proposed protocol with traditional protocols. Experiment results showed that the PRPD protocol improved packet delivery ratio, throughput, and delay compared to the traditional protocols

Challenges And Opportunities For The Development Of Infrastructure After ‘Oda Graduation’ - Moving Towards Sustainable Development: Case Study Of Vietnam

The research on ODA will be focused on its relation to Goal 17, the Partnership, considered a major issue by the researchers, especially in the case of Vietnam as a developing economy. ODA was mainly used for investing in economic infrastructure when Vietnam witnessed a downfall in receiving financial aid due to its significant economic growth. ODA helped Vietnam transform from one of the world’s poorest nations into a lower middle-income country and soon, this is going to lead to the ‘ODA Graduation’. However, the process has just begun. The country is still in a process of industrialization and modernization and its socio-economic situation has not been stable or solid. By all means, ODA is not only a financial resource, it also helps the country to accomplish Sustainable Development Goals (SDGs) of the UN. ‘ODA Graduation’ means that the economy of Vietnam has faced certain challenges such as increasing pressure of outbound debts; raising impact on social development or imbalance between high capital recovery investments and public-services investments. However, ‘ODA Graduation’ has brought certain opportunities such as increasing Vietnam’s independence in capital mobilization, preventing the removal of tariffs barrier, reducing losses and waste of funds. This research gives recommendations for improving Vietnam’s economic situation and can help overcome the difficulties in the period of ‘ODA Graduation’

Challenges And Opportunities For The Development Of Infrastructure After ‘Oda Graduation’ - Moving Towards Sustainable Development: Case Study Of Vietnam

The research on ODA will be focused on its relation to Goal 17, the Partnership, considered a major issue by the researchers, especially in the case of Vietnam as a developing economy. ODA was mainly used for investing in economic infrastructure when Vietnam witnessed a downfall in receiving financial aid due to its significant economic growth. ODA helped Vietnam transform from one of the world’s poorest nations into a lower middle-income country and soon, this is going to lead to the ‘ODA Graduation’. However, the process has just begun. The country is still in a process of industrialization and modernization and its socio-economic situation has not been stable or solid. By all means, ODA is not only a financial resource, it also helps the country to accomplish Sustainable Development Goals (SDGs) of the UN. ‘ODA Graduation’ means that the economy of Vietnam has faced certain challenges such as increasing pressure of outbound debts; raising impact on social development or imbalance between high capital recovery investments and public-services investments. However, ‘ODA Graduation’ has brought certain opportunities such as increasing Vietnam’s independence in capital mobilization, preventing the removal of tariffs barrier, reducing losses and waste of funds. This research gives recommendations for improving Vietnam’s economic situation and can help overcome the difficulties in the period of ‘ODA Graduation’

Generation Z willingness to pay for sustainable apparel: the influence of labelling for origin and eco-friendly material

The purpose of this study is to identify the willingness to pay (WTP) and trade-off that Vietnamese generation Z consumers could make when purchasing eco-friendly apparel. This research uses the Discrete Choice Experiment methodology to measure consumers' WTP and how consumers trade off among different attributes, including eco-friendly, origin, manufacturing technology, and materials. The results show that generation Z consumers are willing to pay for organic label products at a higher price of 21.22% and eco-friendly label items at a higher price of 37.72%. Consumers who have a higher level of corporate social responsibility (CSR) awareness and higher income are willing to pay more for organic and eco- friendly label apparel. They were least willing to purchase apparel that is made in China, while they see no difference between T-shirts made in Vietnam and in other countries except China. Consumers in the current study were more willing to purchase eco-friendly as compared to organic apparel. The findings suggest that enterprises should consider the language used when communicating with consumers. Also, consumers prefer products made in Vietnam, suggesting the promotion of domestic manufacturing through in-depth branding, product positioning, and promotions. The results also confirm that the application of CSR in enterprises is the right and necessary step to be taken for businesses to develop in a sustainable integration world