Jimei University

About: Jimei University is a education organization based out in Amoy, China. It is known for research contribution in the topics: Computer science & Population. The organization has 4645 authors who have published 4293 publications receiving 42239 citations. The organization is also known as: Jíměi Dàxué.

Identification and Characterization of the Tyrosinase Inhibitory Activity of Caffeine from Camellia Pollen.

Abstract: Tyrosinase inhibitors are important in cosmetic, medical, and food industries due to their regulation of melanin production. A tyrosinase inhibitor was purified from Camellia pollen using high-speed countercurrent chromatography and preparative high-performance liquid chromatography and was identified as caffeine by NMR and mass spectrometry. It showed strong mushroom tyrosinase inhibitory activity with an IC50 of 18.5 ± 2.31 μg/mL in a noncompetitive model. The caffeine did not interact with copper ions in the active center of the enzyme but could quench fluorescence intensity and change the secondary conformation of this tyrosinase. A molecular dynamics simulation showed that caffeine bound this tyrosinase via Lys379, Lys 376, Asp357, Glu356, Thr308, Gln307, Asp312, and Trp358, thus changing the binding sites of l-tyrosine and the loop conformation adjacent to the active center. In vitro cell model analysis revealed that caffeine exhibited significant inhibitory effects on both intracellular tyrosinase activity and melanin production of B16-F10 melanoma cells in a concentration-dependent manner. These comprehensive results suggest that caffeine is a strong tyrosinase inhibitor that has the potential to be developed as skin-whitening agents in the cosmetics and pharmaceutical industries or as antibrowning agents in the food industry.

Effect of web hole spacing on axial capacity of back-to-back cold-formed steel channels with edge-stiffened holes

Abstract: Recently, a new generation of cold-formed steel (CFS) channel section with edge-stiffened web holes has been developed by industry in New Zealand. However, no research has been reported in the literature to investigate the axial capacity of back-to-back channels with edge-stiffened web holes. This paper presents a total of 73 new results comprising 29 compression tests and 44 finite element analyses (FEA) on axial capacity of such back-to-back CFS channels. The results show that for back-to-back channels with seven edge-stiffened holes, the axial capacity increased by 19.2%, compared to plain channels without web holes. A non-linear finite element (FE) model was developed and validated against the test results. The validated FE model was used to conduct a parametric study involving 44 FE models. Finely, the tests results were compared with the design strengths calculated from the AISI and AS/NZ standards and from the proposed design equations of Moen and Schafer. From the comparison results, it was found that the AISI and AS/NZ design strengths are only 9% conservative to the test results for plain channels without web holes. While Moen and Schafer equations are conservative by 13% and 47% for axial capacity of CFS back-to-back channels with un-stiffened and edge-stiffened web holes, respectively.

Do higher education research and development expenditures affect environmental sustainability? New evidence from Chinese provinces

Abstract: Even though higher education RD FDI and CO2e; GDP and CO2e; POP and CO2e; and HEEXP and CO2e. This paper's findings call for devising policies and strengthening financial support to induce higher education for developing green patents.

A Summary of Studies on the Automation of Ship Collision Avoidance Intelligence

Abstract: In this paper,the authors firstly make a brief discussion on the significance,the basic process and research contents of the automation collision avoidance for ships at sea.Then the authors emphatically analyze the present situation and direction,the main problems and methods in this field in both internal and international area,and point out the subjects urgently needed to be studied on the automation collision avoidance for ships in future.