Study on the contamination level and dietary exposure of 9,10-anthraquinone in different types of teas in Wuhan / 公共卫生与预防医学

Objective To investigate the pollution level of 9,10-anthraquinone in teas sold in Wuhan, and to assess the dietary exposure of 9,10-anthraquinone ingested through tea. Methods The content of 9,10-anthraquinone in teas collected from local tea markets in Wuhan was analyzed by GC-MS/MS. Results 9,10-anthraquinone was detected in all 36 tea samples with a concentration ranging from 0.0080 mg/kg to 0.137 mg/kg. The standard limit for 9,10-anthraquinone has not yet been set in China. Referring to EU standards, the total over-standard rate was 86.11% (31/36). Generally, the concentration of residual 9,10-anthraquinone was higher in highly fermented teas. The highest average concentration of residual 9,10-anthraquinone was found in fully/post-fermented tea (0.0762 mg/kg), and the over-standard rate was 100%. The second highest was in semi-fermented tea (0.0452 mg/kg), and the over-standard rate was 86.7%. The concentration of 9,10-anthraquinone in non-fermented tea was 0.0262 mg/kg, and the over-standard rate was 42.9%. According to people’s tea-drinking habits, tea samples were brewed with boiling water（1:50）for 5 minutes, and the concentration of 9,10-anthraquinone in tea soup was 0.0004 mg/kg～0.01 mg/kg, with an average leaching rate of 7.2%. The average daily intake exposure of tea for an adult was 0.0551μg/kg bw/day. Conclusion There was a certain degree of 9,10-anthraquinone pollution in the teas sold in Wuhan, and the rate exceeding the standard was high. Since the acceptable daily intake (ADI) for 9,10-anthraquinone has not been established, it is impossible to assess the health risks of 9,10-anthraquinone ingested through tea.

Note: Laser Doppler velocimeter using a dual-longitudinal-mode laser source.

This paper presents a new laser Doppler technique using a dual-longitudinal-mode He-Ne laser as the laser source. Theoretical analysis shows that the Doppler frequency is proportional with the frequency difference of the two modes. The Doppler frequency in this technique is very low compared with the one in the single-mode laser Doppler technique. The new laser Doppler technique can be used to measure high speed. Experiment results show that the Doppler frequency is only about 82 Hz while the measurement speed reaches 31.4 m∕s. The signal-to-noise ratio of the Doppler signal is improved by the technique of digital filter and digital autocorrelation.

Histochemical features of the Muscovy duck small intestine during development.

We demonstrated for the first time the distribution and morphology of argyrophil and of goblet cells in the mucosa of the small intestine of the Muscovy duck during development using the Grimelius silver staining and alcian blue/periodic acid-Schiff (AB/PAS) staining technique. The argyrophil cells distribution was variable over the length of the small intestine from embryonic day 24 (24E) to post-hatching day 13 (13d). In the villi most argyrophil cells belonged to the open-type, while in the crypts they belonged to the closed-type. In the duodenum the density of argyrophil cells was highest at hatching, while in the jejunum and in the ileum the highest density value was at hatching and 13d. AB/PAS-positive goblet cells appeared on the villi and crypts of the duodenum and jejunum at 30E, and in the ileum at hatching. The density of AB/PAS-positive cells was the highest in the three segments at hatching. The AB-positive cells, compared with the PAS-positive cells, predominated in villi and crypts of the three segments, moreover the rate of AB-positive cells to PAS-positive cells significantly decreased from 30E to 9d. An increase in argyrophil and goblet cells number during the later incubation and at hatching, could indicate the small intestine in that period is being prepared to face a new diet.

Design of medical vacuum knife / 医疗卫生装备

Medical vacuum knife (MVK) is a new approach for liver surgery. This paper introduces its principles and applications. Some detailed issues related to MVK are also presented such as its differences from other methods, its development and application perspective to abdominal surgery.