Objective To determinate the contents of α-pinene, β-pinene, eucalyptol and linalool in Baeckea frutescens by reference substances method and reference extract method respectively; To explore the feasibility of replacing single component reference by control extracts in assay. Methods The GC system consisted of a quartz column DB-5 (60 m×0.25 mm×0.25 μm); The temperature programming rose from 80 ℃ (15 min) to 90 ℃ by 1 ℃/min, lasting 2 min, then 10 ℃/min to 110 ℃, then 25 ℃/min to 240 ℃, lasting 8 min in the end; The temperature of the entrance of capillary vessel column was 250 ℃, and the temperature of the detector was 250 ℃. Results α-pinene, β-pinene, eucalyptol and linalool were in a good linear relationship within each concentration scope (r≥0.999). The average recovery rates were in the range of 96.5%–102.2%. The results of t-test demonstrated that there is no significant difference between the two methods. Conclusion The reference extract method can be used as a quality evaluation pattern for Baeckea frutescens.

Objective To analyze the spatial distribution patterns of rodent community and the risk factors of disease transmission in natural foci of Xiji County,Ningxia,in order to provide a scientific basis for disease control and prevention.Methods Rodents were captured at different habitats in different latitudes which were selected with a stratified sampling method in 2012-2013.Capture rate of different rodent species and spatial distribution patterns of the animal community were analyzed.Antigen and antibody of hantavirus were detected in lung tissue and blood of the rodents with immunofluorescence and enzyme-linked immunosorbent assay (ELISA),respectively.Serum F1 antibody of Yersinia pestis (Y.pestis) was detected with indirect hemagglutination test and Y.pestis from liver and spleen tissue was cultured in vitro.Results Fourteen species of rodents were captured,belonging to 2 orders,7 families and 9 genera.Among them,ground squirrels and wood mouse were dominant species,accounted for 49.56％ (112/226) and 34.51％ (78/226) of the community,respectively.Infections of hantavirus and Y.pestis were not found in the rodent's community.Conclusion With the improvement of ecological environment in Xiji County,the spatial distribution patterns of rodent community is changing; the risk of zoonotic plague is reduced,but the risk of hemorrhagic fever with renal syndrome is being.