Artemisinin is the antidote to malaria, and has made hundreds of millions patients get rid of the disease since application in clinic. At present, the main accesses to artemisinin are directly extracted from Artemisia annua,chemical synthesis and biosynthesis. By comparing the differences of artemisinin production process between China and abroad, this research analyzes the reasons of the problem, and put forward their views and suggestions, so as to provide references for Artemisia annua further research.

OBJECTIVE:To establish the fingerprint of Artemisia apiacea to identify common model and evaluate the quality coherence of the commercially available A. apiacea decoration pieces in Chongqing. METHODS:HPLC method was performed on the column of Waters XTerra C18 with the mobile phase consisted of methanol-0.1% phosphoric acid(gradient elution)at the flow rate of 1.0 ml/min. The detection wavelength was 220 nm,column temperature was 30 ℃ and the sample size was 10 μl. The simi-larity of 12 batches of samples was evaluated by TCM Chromatogram Fingerprint Similarity Evaluation System(2004A edition);a common model of fingerprints was identified by principal component analysis(PCA)and cluster analysis(CA). RESULTS:Total-ly 11 batches of samples were screened to establish common model of fingerprints and 16 common peaks were obtained,among which,3 common components were identified;RSDs of precision,stability and reproducibility tests were lower than 2.53%. The similarity of 11 batches of A. apiacea and reference chromatogram was more than 0.990. CONCLUSIONS:The method is stable and easy,and can provide reference for the scientific quality evaluation and control of A. apiacea;the quality of commercially available A. apiacea decoration pieces is generally good,however,there is still a little number of batches with poor quality. The production procedures and supervision of A. apiacea decoration pieces should be strengthened.

We have brought forward a wavelet-based algorithm for electroencephalograph (EEG) signals--using scale dependent threshold based on median. In comparison with the universal threshold and Sure threshold, our proposed threshold, which is adaptive to the subband noise signals, preserves the noise free reconstruction property and takes lower risk than does the universal threshold; and our proposed threshold overcomes the drawback of Sure threshold. Evidently, the scale dependent threshold based on median is computationally simple and can obtain higher singal-to-noise ratio (SNR) it outperforms the universal threshold and Sure threshlold.
Algorithms ; Artifacts ; Electroencephalography ; Humans ; Signal Processing, Computer-Assisted

Objective To construct engineered corneal epithelium from embryonic stem cells (ESCs) using Rock inhibitor combined with hypoxia-normoxia culture condition. Methods Human ESC line H1 was induced to differentiate into epithelial-like cells by addition of retinoic acid (RA) and bone morphogenetic protein 4(BMP4) in the differentiation medium under the adherent culture condition. The ESCs derived epithelial-like cells were expanded in the mixed medium of SHEM and KSFM with the mixture ratio of 1 : 2 with or without Rock inhibitor Y27632. The H1 derived epithelial-like cells were seeded on the denuded ammonic membrane to construct engineered corneal epithelium under hypoxia,normoxia and hypoxia-normoxia culture conditions,respectively. The inducted effect of ESCs into epithelial-like cells,the expansion ability of the epithelial-like cells and the characteristics of the constructed engineered corneal epithelium were evaluated by morphological observation, real-time fluorescent quantitative polymerase chain reaction (RTFQ-PCR) and immunofluorescence technology. Results Compared with the control group,the relative expressions of ESCs marker Oct4 mRNA, Notch signaling pathway related factors Notch1 and Jagged1 mRNA,and Wnt signaling pathways related factors c-myc and Cyclin D1 mRNA were significantly reduced, and the relative expressions of cutaneous ectoderm markers p63 and K18 mRNA were significantly increased at day 8 after induction in the induced group,with significant differences between them (t =14.63,20.15,93.50,11.60, 19.30,18.44,22.63;all at P<0.05). Compared with the without Y27632 group,the relative expressions of p63 and K14 mRNA,Notch signal pathway receptor Notch1 and Jagged1 mRNA were significantly increased,and Wnt signaling pathways downstream targeted gene c-myc and CylinD1 mRNA were significantly decreased at day 8 after induction in the Y27632 group,with significant differences between them (t =20.29,59.22,2.90,39.59,5.32,10.14;all at P<0.05),and the relative expression of K18 mRNA in the two groups was not significantly changed(t=1.38,P>0.05). The ESCs derived epithelium and constructed under hypoxia-normoxia culture condition showed more obvious stratification and tighter cell arrangement in comparison with those cells cultured in consistent hypoxia culture condition or normoxia culture condition. Epithelial markers Pan-CK and K18 as well as epithelial progenitor cell markers p63 and K14 expressed in the whole cell layers of the ESCs derived epithelium constructed under hypoxia-normoxia culture condition. Conclusions The addition of Y27632 enhances the proliferation ability of H1 derived epithelial cells and actives Notch signaling pathway and inhibits Wnt signaling pathway. The culture and construction in the expansion medium with Y27632 under the hypoxia-normoxia culture condition can promote the stratification of H1 derived engineered corneal epithelium.