Research progress on pesticide residues of Panacis Quinquefolii Radix / 中国中药杂志

Panacis Quinquefolii Radix is the dry root of Panax quinquefolium, which is a perennial plant of Araliaceae. The plant has a long growth cycle and serious growth barrier problem, which leads to the use of pesticides. As a result, the pesticide residues in Panacis Quinquefolii Radix are arousing great concern. This paper reviews the research findings on the investigation, detection methods, content analysis and risk assessment of pesticide residues in Panacis Quinquefolii Radix since 1993, and compares the pesticide residue limit standards of different countries and regions. The pesticide residues in Panacis Quinquefolii Radix have been changing from organochlorines with high toxicity to triazines and triazoles with low toxicity. The pesticide residues are generally low, while the pollution of pentachloronitrobenzene and other pesticides still exist. The detection method has evolved from chromatography to chromatography-mass spectrometry. There are no reports of health risks caused by pesticide residues of Panacis Quinquefolii Radix. Pesticide residue is a major factor restricting the sound development of Panacis Quinquefolii Radix industry in China. Therefore, we suggest to improve the registration of pesticides applied to the plant, popularize mature ecological planting mode and supporting technology, and strengthen the research on the risk assessment and limit standard of pesticide residue in Panacis Quinquefolii Radix.

[Dynamic comparisons of epicardial electrograms between the left atrium and pulmonary veins in atrial fibrillation in goat model].

Objective: To compare epicardial electrograms between the left atrium (LA) and pulmonary veins (PVs) dynamically at development of persistent atrial fibrillation(AF) in goats PVs. Methods: Ten female goats were instrumented with electrodes at the LA and left side PV. Sustained AF (＞24 h) was induced in the goat by rapid intermittent left atrial pacing for(9.5±2.3)days at a pacing interval of 20 ms for 1 s with a maximum output of 6.0 V, followed by a 2-s period without pacing. Characteristics of PVs and LA epicardial electrograms were analyzed in the development of AF. Results: With prolonged stimulation, the duration of AF was prolonged, complex fractionated atrial electrograms(CFAEs) in LA and was increased gradually, PVs had more CFAEs than LA all the time. When induced AF lasted for more than 24 h, CFAEs in PVs became sustained approximately (2.7%±3.6% vs 92.6%±6.4%, at onset of AF vs AF lasted for more than 24 h, P＜0.05), and the ratio of CFAEs in PVs was more than that in LA (92.6%±6.4% vs 72.8%±5.3%, P＜0.05). Conclusion: The epicardial CFAEs are in specific area, which increase along with electrical remodeling. The epicardial CFAEs may play an important role in the maintenance of AF in this model.

Analyze moisture transformation and transport rules during processing of Paeoniae Radix Alba by using low-field NMR / 中国中药杂志

Moisture status and content during the processing of Paeoniae Radix Alba were studied by nuclear magnetic resonance (NMR) and nuclear magnetic resonance imaging (MRI) to investigate the changes of transverse relaxation time (T ₂) and MRI images during boiling and drying processes of Paeoniae Radix Alba. The results showed that water in Paeoniae Radix Alba fresh products was major of free water, and in the boiling process, the content of free water increased whereas the content of bound water declined. At the end of boiling, content of free water reached over 90%. During the drying process, T ₂ moved to the left, and moisture mobility was reduced. The MRI image directly showed that moisture transfer was outside-in process for both increase and decrease. At the end of drying, remaining moisture was mainly present in inner layer of Paeoniae Radix Alba. Quality and appearance were affected by the change of moisture during processing process of medicinal herbs. NMR and MRI could provide direct reference evidence for its moisture changes, and the results of this study could provide direct references and technical support for optimization of processing process of root medicinal materials and evaluation of Chinese herbal pieces.