Processing of calamine with modern analytical techniques: Processed with Huanglian Decoction () and Sanhuang Decoction () / 中国结合医学杂志

<p><b>OBJECTIVE</b>To determine the pyrolysis characteristics of calcined and processed calamine, qualitatively and quantitatively compare the contents of related elements, morphology and functional groups of the pyrolysis products dried at different heating temperatures and explore the critical temperature and the optimal drying temperature for the process of calamine with Huanglian Decoction (HLD, ) and San Huang Decoction (SHD, ).</p><p><b>METHODS</b>Pyrolysis products were prepared by programmable and constantly heating the calcined and processed calamine to or at different heating temperatures. Thermogravimetry (TG) was used to test their pyrolysis characteristics. Fourier transform infrared spectroscopy and scanning electron microscopeenergy dispersive spectrometer were used to determine their morphology, functional groups and element contents. Page model was used to investigate the constant drying kinetics of processed calamine.</p><p><b>RESULTS</b>The adding of HLD or SHD to calcined calamine (CC) can slow its weight loss in drying pyrolysis process. The temperature ranges where HLD and SHD can affect its weight loss were 65-150 °C and 74-180 °C, respectively. The drying temperature was optimized as 90 °C. The drying kinetic for the processed calamine fits Page model shows good linearity.</p><p><b>CONCLUSIONS</b>Conclusions: The critical temperature and the optimal drying temperature where HLD and SHD can affect the weight loss rate in the process of calamine were explored using the theories and methods of both biophysical chemistry and processing of Chinese materia medica. This work provides a good example for the study of the process of other Chinese medicines using modern analytical techniques.</p>

An experimental study on pulmonary toxicity water extracts of Siegesbeckia pubescens on mice / 中国中药杂志

<p><b>OBJECTIVE</b>The pulmonary toxicity of water extract of Siegesbeckia pubescens has been studied an mice following subchronic oral administration route.</p><p><b>METHOD</b>Mice were randomly grouped and administered with the water extract of S. pubescens at dosages of 3.0, 1.0, 0.3 g x kg(-1) and saline respectively. 10 mice of each group were sacrificed on the day of 7 th, 14 th, 21 th, and 2 weeks after stopping administration, histological changes of the lung were examined.</p><p><b>RESULT</b>The water extract of S. pubescens at dosage of 3.0 g x kg(-1) increased the lung index on the of day 14 th and 21 th, significant histopathological damages were observed. The histopathological changes were disappeared after stopping administration for 2 weeks.</p><p><b>CONCLUSION</b>The water extract of S. pubescens has a pulmonary toxic effect on mice, and the toxic effect is reversible.</p>

Enzyme-amplified time-resolved fluorescence detection for nucleic acid hybridization assays / 中国医学科学院学报

<p><b>OBJECTIVE</b>To develop a new nonisotopic detection method of enzyme-amplified time-resolved fluorescence (EATRF) or enzyme-amplified lanthanide luminescence (EALL) for nucleic acid hybridization assays, which can be applied extensively in clinical diagnosis.</p><p><b>METHODS</b>The method combines the high affinity of biotin-streptavidin system, amplification of enzyme, and inherent advantage of lanthanide chelate with the background elimination of time-resolved fluorescence detection. The conversion of 5-fluorosalicyl phosphate to 5-fluorosalicylic acid (5-FSA) by alkaline phosphatase. The salicylic acid product forms a luminescent ternary chelate with Tb3+ and EDTA.</p><p><b>RESULTS</b>The dynamic range of the standard curve of EATRFA for nucleic acid hybridization assay was very wide, the range was more than third order of magnitude. The detection sensitivity was about 10 pg of target sequence. When the known target sequence was 20, 10 and 2 ng, the ratio of measured amount to known amount was 110%, 90% and 115% respectively. The main experimental conditions, for example, the irradiating time of ultraviolet rays, the concentrations of biotinylated probe, AP-SA, 5-FSAP and Tb-EDTA and the methods of washing in the related steps, have been optimized. A new stable technology of fluorescence has been developted.</p><p><b>CONCLUSIONS</b>EATRF detection for nucleic acid hybridization assays is a new sensitive simple method, which has a great prospect.</p>