BackgroundThe reproducibilty of dengue IgM and IgG ELISA was studied in serum and filter paper blood spots from Vietnamese febrile patients.Methods781 pairs of acute (t0) and convalescent sera, obtained after three weeks (t3) and 161 corresponding pairs of filter paper blood spots were tested with ELISA for dengue IgG and IgM. 74 serum pairs were tested again in another laboratory with similar methods, after a mean of 252 days.ResultsCases were classified as no dengue (10 %), past dengue (55%) acute primary (7%) or secondary (28%) dengue. Significant differences between the two laboratories' results were found leading to different diagnostic classification (kappa 0.46, p < 0.001). Filter paper results correlated poorly to serum values, being more variable and lower with a mean (95% CI) difference of 0.82 (0.36 to 1.28) for IgMt3, 0.94 (0.51 to 1.37) for IgGt0 and 0.26 (-0.20 to 0.71) for IgGt3. This also led to differences in diagnostic classification (kappa value 0.44, p < 0.001) The duration of storage of frozen serum and dried filter papers, sealed in nylon bags in an air-conditioned room, had no significant effect on the ELISA results.ConclusionDengue virus IgG antibodies in serum and filter papers was not affected by duration of storage, but was subject to inter-laboratory variability. Dengue virus IgM antibodies measured in serum reconstituted from blood spots on filter papers were lower than in serum, in particular in the acute phase of disease. Therefore this method limits its value for diagnostic confirmation of individual patients with dengue virus infections.However the detection of dengue virus IgG antibodies eluted from filter paper can be used for sero-prevalence cross sectional studies.

In this study, Rhodomyrtus tomentosa (Ait.) Hassk. (sim) fruits were treated with UV-B radiation for 0, 1, 3 and 6 hours with an average fluency rate of 0.67 mW/cm 2 at a distance of 30 cm. Fruits were, then, stored at 8 °C to 10 °C for 21 days. During storage, the fruits were analysed for hardness, total soluble solids, and total dry matter every 7 days. The total phenolics, total anthocyanins and antioxidant capacity of the skin+pulp and the seed parts were determined. The results showed that the storage time and UV-B irradiation time significantly affected the antioxidant phenolic content of both skin+pulp and seed parts. The total polyphenols and antioxidant capacity increased immediately after UV-B treatment and decreased during storage. UV-B irradiation slowed down the decrease of antioxidant phenolic compounds in the fruit during storage. This indicated that UV-B irradiation could be a potential way to enhance phenolic antioxidants in fruits rich in phenolics.

Using intellectual property as collateral for loans is widely accepted around the world, but this is new in Vietnam despite the allowance of contemporary legal regulations. This is an opportunity for individuals and enterprises in Vietnam. However, in practice, accessing loans by mortgaging intellectual property at banks in Vietnam is challenging. The difficulties may come from the lack of detailed regulations, the challenge of valuating “intangible” intellectual property, or potential conflict resolutions. This paper examines the issue from a legal perspective and shows difficulties when mortgaging intellectual property in Vietnam.