[Fluorescence Properties of Glomalin and Its Relationship with Soil Physyicochemical Characteristics in Different Regions of Beijing City].

Glomalin-related soil proteins (GRSP), which has been used as a presumable biological indicator of soil quality, is of vital ecological importance. In this research, we tested the GRSP content and physicochemical property of soils collected in mountain, urban and suburb areas of Beijing City. Besides, the fluorescence property of GRSP was also studied by using EEM-PARAFAC. The results showed that GRSP could be decomposed into five compounds, terrestrial humic-like substances UVA, terrestrial humic-like substances UVC, oxidized quinones, soil fulvic acid and amino acids. The GRSP content and protein-like fluorescence substances in urban and suburb areas significant decreased and oxidized quinones content elevated in comparison with those in mountain area. The physicochemical property was also shaped by urbanization. Compare to mountain area, moisture content, total organic matters and total nitrogen significantly decreased in urban area soil and suburb area. GRSP content, terrestrial humic-like substances UVA and oxidized quinones content showed significant correlation with soil organic matter and total nitrogen. Base on that, an integrated index system mainly consisting of GRSP concentration and C1 component and C3 component was recommended to evaluate the soil health status.

[A new bioassay model of antibiotic susceptibility by corneofungimetry].

OBJECTIVE: To study the value of a new bioassay model of antibiotic susceptibility by corneofungimetry which is more similar to human internal environment. METHODS: Twenty-one healthy adult volunteers, 12 males and 9 females, aged 32 (22 - 41), were randomly divided into two groups to receive itraconazole 200 mg Bid or 200 mg qd or bid for one week. Stratum corneum strippings were taken from the forearm skin once before administration of itraconazole and 1, 4, 7, 10, 14, 21, 28, and 35 days after administration of itraconazole. Spores of selected fungi (Trichophyton rubrum, T. mentagrophytes, Microsporum canis, Candida albicans, C. glabrata and C. tropicalis) were deposited and cultured on the strippings. PAS stain was used after one-week culture to observe the growth of the fungi by computerized-assisted image analysis to measure the area covered by the yeasts and the dermatophyte. RESULTS: All fungi grew on all the stratum corneum strippings with different numbers of hyphae. The areas covered by hyphae and spores decreased gradually after administration of itraconazole, became the smaller on the seventh day (P = 0.01 or P < 0.01), and began to increased since the 10 th day, and became almost the same sizes as those before the administration of itraconazole on the 35 th day. CONCLUSION: Similar to the human internal environment, corneofungimetry is a useful new model of bioassay for antibiotic susceptibility.