Study on Quality Standard of Tibetan Medicine Corydalis dasyptera Maxim.

[Objectives]To establish the quality standard of Tibetan medicine Corydalis dasyptera Maxim.[Methods]According to the research method of drug quality standard in the appendix of 2020 edition of Chinese Pharmacopoeia,8 batches of C.dasyptera Maxim.from different habitats were studied by character identification,microscopic identification and TLC identification.The content of water,total ash,acid-insoluble ash and alcohol-soluble extract was determined,and the content of protopine in medicinal materials was determined by high performance liquid chromatography(HPLC).[Results]The properties and microscopic characteristics of C.dasyptera Maxim.were determined.The TLC characteristic spots of the medicinal materials were clear,the degree of separation was good,and the specificity was strong.Both the test sample and the control sample showed the same yellow-green spots in the corresponding position.It was tentatively determined that the water content of C.dasyptera Maxim.should not exceed 14.0%,the total ash content should not exceed 14.0%,the acid-insoluble ash content should not exceed 3.0%,and the alcohol-soluble extract content should not be less than 18.0%.There was a good linear relationship between the concentration of protopine and the peak area in the range of 16.64-166.40μg·10-3(r=0.9996).The average recovery rate was 98.47%and the RSD was 1.21%(n=6).The content of protopine in 8 batches of C.dasyptera Maxim.was 0.023%-0.093%.[Conclusions]The established quality research method is simple,stable and reliable,and can be used for the quality control of C.dasyptera Maxim.

Seafloor geodetic network establishment and key technologies

Seafloor geodetic network construction involves the development of geodetic station shelter, network configuration design, location selection and layout, surveying strategy, observation model establishment and optimization, data processing strategy and so on. This paper tries to present main technological problems involved in the seafloor geodetic network construction, and seek the technically feasible solutions. Basic conceptions of developing seafloor geodetic station shelters for shallow sea and deep-sea are described respectively. The overall criteria of seafloor geodetic network construction for submarine navigation and those of network design for crustal motion monitoring are both proposed. In order to enhance application performances of the seafloor geodetic network, the seafloor network configuration should prefer a symmetrical network structure. The sea surface tracking line measurements for determining the seafloor geodetic station position should also adopt an approximately symmetrical configuration, and we recommend circle tracking line observations combined with cross-shaped line(or double cross-shape line) observations for the seafloor positioning mode. As to the offset correction between the Global Navigation Satellite System antenna phase center and the acoustic transducer, it is recommended to combine the calibration through external measurements and model parameter estimation. Besides, it is suggested to correct the sound speed error with a combination of observation value correction and parameterized model correction, and to mainly use the model correction to reduce the influence of acoustic ray error on the seafloor positioning. Following the proposed basic designs, experiments are performed in shallow sea area and deep-sea area respectively. Based on the developed seafloor geodetic shelter and sufficient verification in the shallow sea experiment, a long-term seafloor geodetic station in the deep-sea area of 3000 m depth was established for the first time, and the preliminary positioning result shows that the internal precision of this station is better than 5 cm.

Seldom-segment versus multi-segment intramedullary spinal cord gliomas: a comparative clinical study

Dear Editor,Glial tumors (80%), astrocytomas, and ependymomas are the most frequent histological types of intramedullary spinal cord tumors (Bansal et al., 2013). Intramedullary tumors spanning three or more vertebral body levels are considered multi-segment intramedullary spinal cord tumors and have a much lower incidence than less involved tumors (Wang et al., 2012). We prospectively studied 81 consecutive patients who underwent resection of intramedullary spinal cord gliomas at a single medical center (The Neurosurgery Department of Peking University Third Hospital) between January 2010 and December 2015 to compare the neurological function and prognosis of patients with seldom-segment and multiple-segment intramedullary spinal cord gliomas.