Objective: To develop an approach for simultaneous detection of multi-mycotoxins in fresh fruits, so as to provide technical supports for mycotoxins surveillance in fresh fruits. Methods: Fresh fruits were collected from markets and homogenized. Then, 2 g of fresh fruits were added with 10 mL of 0.1% formic acid ( 99∶1, v/v ) in acetonitrile and wortexed for 10 min. Following extraction with 1 g of sodium chloride and 4 g of anhydrous sodium sulfate, samples were centrifuged and 5 mL of the supernatant was cleaned up with 25 mg C18. Following centrifugation, the supernatant was dried under nitrogen. The residue was dissolved in 300 μL of methanol-acetonitrile mixture solution ( 1∶1, v/v ), and mixed evenly in 700 μL of the distilled water. Samples were then eluted in gradient series of 0.1% formic acid and 5 mmol ammonium formate and methanol-acetonitrile mixture solution ( 1∶1, v/v ). The 15 mycotoxins were determined using liquid chromatography-tandem mass spectrometry ( LC-MS/MS ) with electrospray ion source (ESI+/ESI-) under multiple reaction monitoring. In addition, a matrix-matched standard curve was employed for quantitative analysis. Results: There was a good linear relationship for 15 mycotoxins at concentrations of 0.25 to 10 ng/mL ( R2>0.992 ), the LC-MS/MS method showed the detection limits of 0.1-1.0 μg/kg, the spiked recovery rates of 71.68%-117.50%, and the relative standard deviations ( RSDs ) of 0.01%-13.60%. The detection rate of mycotoxins was 27.09% in 203 fresh fruits sold in markets. Conclusions The optimized LC-MS/MS method can be used for simultaneous determination of multi-mycotoxins in fresh fruits.

Quality variation and ecotype classification of Chinese herbal medicine are important scientific problems in Daodi herbal medicine research. The diversity of natural environmental conditions has led to form unique multi-Daodi, multi-product areas that produce particular Chinese herbal medicine. China is one of three big American ginseng (Panax quinquefolium L.) producing areas worldwide, with over 300 years of application and 40 years of cultivation history. Long-term production practice has led to the formation of three big advocate produce areas in China: Northeast province, Beijing and Shandong. P. quinquefolium L. grown under certain environmental conditions will develop long-term adaptations that will lead to more stable strains (different ecotypes). P. quinquefolium L., can vary greatly in quality; however, the ecological mechanisms causing this variation are still unclear. Root samples were collected from four-year-old cultivated P. quinquefolium L. plants in the three major genuine (Daodi) American ginseng-producing areas of Northeast province, Beijing and Shandong province, China. Ultra-performance liquid chromatography was used to analyze the contents of eight ginsenosides (Rg1, Re, Rb1, Rb2, Rb3, Rc, Rd, Rg2). Data for nine ecological factors, including temperature, moisture and sunlight, were obtained from the ecological database of Geographic Information System for Traditional Chinese Medicine. Soil samples from the sampling sites were collected. Effective boron and iron, available nitrogen and potassium, as well as other trace elements and soil nutrients, were determined by conventional soil physicochemical property assay methods. Analytical methods of biostatistics and numerical taxonomy were used to divide ecotypes of the three main Panax quinquefolium L. producing areas in China based on ginsenoside content, climate, soil and other ecological factors. To our knowledge, this is the first time that ecological division of P. quinquefolium L. producing areas in China has ever been conducted. The results show that there are two chemoecotypes of P. quinquefolium L. in China: ginsenoside Rb1-Re from outside Shanhaiguan, and ginsenoside Rg2-Rd from inside Shanhaiguan. Similarly, there are two types of climatic characteristics: inside Shanhaiguan (Beijing, Shandong) and outside Shanhaiguan (Northeast). This suggests that the formation and differentiation of chemoecotypes of P. quinquefolium L. is closely related to variability of the climatic and geographical environment. Additionally, ecological variation of the three main producing areas, characteristics of two climatic ecotypes, and soil characteristics are also discussed and summarized. These results provide experimental scientific evidence of the quality variation and ecological adaptation of P. quinquefolium L. from different producing areas. They also deepen our understanding of the biological nature of Daodi P. quinquefolium L. formation, and offer novel research models for other multi-origin, multi-Daodi Chinese herbal medicines ecotypes. In addition, the results demonstrate the critical need for improving quality, appropriate ecological regionalization and promoting industrialized development of P. quinquefolium L.

OBJECTIVE To investigate whether quinolinic acid(QA)induces autophagy in PC12 cells and its relationship with glycogen synthase kinase-3β(GSK-3β)/β-catenin related signaling path?ways. METHODS PC12 cells were treated with QA 2.5,5.0 and 10.0 mmol·L-1 for 24 h. The cell viability was determined by MTT assay. Autophagy fluorescent spots labelled form of microtubule-associated protein 1 light chain 3(LC3)was examined by LC3 immunostaining. The expressions of GSK-3β,β-catenin,LC3 and Beclin 1 were determined by Western blotting. RESULTS QA inhibited PC12 cell survival in a concentration-dependent manner,and IC50 was 8.7 mmol · L- 1. Compared with normal control group,QA 2.5,5.0 and 10.0 mmol · L-1 increased autophagic intracellular LC3 fluorescence spots,elevated the expression ratio of LC3-Ⅱ/LC3-Ⅰ and expression of Beclin 1 in PC12 cells(P<0.05). In addition,QA enhanced GSK-3βexpression and decreasedβ-catenin expression(P<0.05,P<0.01). CONCLUSION QA induces autophagy in PC12 cells. This mechanism may be associated with the activation of GSK-3β/β-catenin related signaling pathways.

To investigate the genetic relatedness between carbapenem-resistant Klebsiella pneumoniae(CRKP) strains isolated from intestinal colonization and subsequent bloodstream infections.