1.Determination of Toluene Diisocyanate in Plastic Playground by Gas Chromatography
Zhengquan SU ; Xiaoyu YUAN ; Yan BAI
Journal of Environment and Health 1993;0(01):-
Objective To establish a rapid,accurate and sensitive method for the determination of toluene diisocyanate(TDI) in plastic playground.Methods The samples were distilled continuously for 12 hours by acetone at 80-85 ℃ in water bath,and after centrifuged,precipitated and filtered,separated by using GC1490,7% SE-30 column,the contents of TDI in the samples were determined by gas chromatography.The qualitative and quantitative analyses were carried out by the retention time and peak area respectively.Results The linear range of the method was 0.001 30-0.043 80 mmol/L.Regression equation was y=28 612x-29.336,with r=0.999,and the limit of detection was 0.001 30 mmol/L.The rates of recovery ranged 100.8%-103.6%,with RSD of 5.7%.Conclusion The developed method was rapid,accurate,sensitive and is applicable to the determination of TDI inplastic playground.
2.Making and application of an ischial weight bearing orthosis
Zhengquan ZHAO ; Xiangdong CHEN ; Qiang SU ; Lin HAN
Chinese Journal of Physical Medicine and Rehabilitation 2008;30(9):619-621
Objective To facilitate standing and walking after rehabilitation training by designing and using individualized ischial weight bearing orthosis for patients with various conditions of the lower limbs. Methods An orthosis with ischial support was ordered and tailored according to the condition of the patient's affected lower limb. Adaptive standing and walking training were administered daily. The functional recovery after the assembly of the orthosis was observed. Results The patients' standing and walking ability improved significantly after the training with the ischial weight bearing orthosis. The standing time was significantly longer than without the orthosis, and the walking distance was notably increased. Conclusion An ischial weight bearing orthosis has a significant effect on the recovery of standing and walking capability.
3.Fingerprint research and multi-component quantitative analysis of Kumu injection by HPLC.
Zhengquan LAI ; Yuyang YI ; Huijun LIAO ; Jiyan SU ; Zhuyuan LIAO ; Ji LIN ; Ziren SU
China Journal of Chinese Materia Medica 2011;36(13):1739-1743
OBJECTIVETo establish the HPLC chromatographic fingerprint of Kumu injection and to simultaneously determine the contents of three beta-carboline alkaloids, comprehensively evaluating the immanent quality of Kumu injection.
METHODThe chromatographic analysis was performed on a Phenomenex Gemini C18 ( 4.6 mm x 250 mm, 5 microm) column with the gradient elution solvent system composed of methanol and 30 mmol x L(-1) aqueous ammonium acetate (adjusted with glacial acetic acid to pH 4.5). Similarity evaluation system for chromatographic fingerprint of traditional Chinese medicine (2004 A) was used in data analysis.
RESULTSixteen co-possessing peaks were selected as the fingerprints of Kumu injection, and 7 peaks were identified by chemical reference substances. There were good similarities between the standard fingerprint chromatogram and each fingerprint chromatogram from the eleven samples for their similarity coefficients were not less than 0.9. Three kinds of beta-carboline alkaloids were separated well. The correlation coefficients were 0.999 9. The linear ranges of three components were 0.020 0-0.300 0, 0.102 0-1.530 0, 0.015 2-0. 228 0 microg, respectively, and the average recoveries ranged were from 99.5% to 102%.
CONCLUSIONThe method of fingerprint combined with quantitative analysis is sensitive, selective, and provide scientific basis for quality control of Kumu Injection.
Alkaloids ; analysis ; Carbolines ; analysis ; Chromatography, High Pressure Liquid ; methods ; Drug Stability ; Drugs, Chinese Herbal ; chemistry ; Injections ; Pharmaceutical Solutions ; Picrasma ; chemistry ; Plants, Medicinal ; chemistry ; Quality Control ; Reproducibility of Results ; Sensitivity and Specificity
4.Mechanism of action of the bile acid receptor TGR5 in obesity.
Weijun LUN ; Qihao YAN ; Xinghua GUO ; Minchuan ZHOU ; Yan BAI ; Jincan HE ; Hua CAO ; Qishi CHE ; Jiao GUO ; Zhengquan SU
Acta Pharmaceutica Sinica B 2024;14(2):468-491
G protein-coupled receptors (GPCRs) are a large family of membrane protein receptors, and Takeda G protein-coupled receptor 5 (TGR5) is a member of this family. As a membrane receptor, TGR5 is widely distributed in different parts of the human body and plays a vital role in regulating metabolism, including the processes of energy consumption, weight loss and blood glucose homeostasis. Recent studies have shown that TGR5 plays an important role in glucose and lipid metabolism disorders such as fatty liver, obesity and diabetes. With the global obesity situation becoming more and more serious, a comprehensive explanation of the mechanism of TGR5 and filling the gaps in knowledge concerning clinical ligand drugs are urgently needed. In this review, we mainly explain the anti-obesity mechanism of TGR5 to promote the further study of this target, and show the electron microscope structure of TGR5 and review recent studies on TGR5 ligands to illustrate the specific binding between TGR5 receptor binding sites and ligands, which can effectively provide new ideas for ligand research and promote drug research.