Search

A mixture of 49 pesticides amenable to gas chromatography (GC) were quantitatively recovered from spiked bamboo shoot, based on QuEChERS-modified, and determined using gas chromatography-tandem mass spectrometry (GC-MS/MS). The method employed involved initial extraction in a acetonitrile,an extraction/partitioning step after the addition of salt,and a cleanup step utilizing dispersive solid-phase extraction by PSA and C18. The sample was dissolved in toluene, and then determined by GC-MS/MS. This combination ensured that it was a rapid, simple and cost-effective procedure. For 49 pesticides, the LOD ranged from 1. 0 to 26. 2 μg/kg respectively,the correlation coefficient was above 0. 99. The spiking levels for the recovery experiments were 10. 0, 50. 0 and 100. 0 μg/kg for GC-MS/MS analyses. Mean recoveries mostly ranged between 62. 5 % and 121. 8 % and relative standard deviations (RSD) were generally 0. 8 %-11. 7%. Based on these results,the methodology has been proved to be highly efficient and robust and thus suitable for monitoring the pesticide residue in bamboo shoot. [ABSTRACT FROM AUTHOR]

Objective To investigate the effects of adenomatous polyposis coli downregulated 1( APCDD1) on the adipogenic differentiation and lipogenesis of bone marrow stromal cells( BMSCs). Methods The cultured BMSCs ST2 were randomly divided into three groups: the blank control group, experimental group, and control group. The APCDD1-overexpression plasmid was constructed by in-fusion cloning. The experimental group and the control group were transfected with APCCD1-overexpression plasmid and pc DNA3. 1 plasmid, respectively, and the blank control group was routinely cultured. Traditional cocktails were used to induce ST2 cells to differentiate into mature adipocytes. The qRT-PCR was applied to detect APCDD1 mRNA expression during adipogenic differentiation in ST2 cells. Lipid droplet formation was monitored by oil-red O staining as well as light absorbance was measured at 520 nm for oil-red O quantification. The expression of the key genes and proteins in ST2 cells were detected by qRT-PCR and Western blotting, respectively. Results The relative mRNA expression of APCCD1 increased at 1-5 d after adipogenic induction as compared with that at 0 d, and the highest expression of APCCD1 was observed at 2 d( all P < 0. 05). After transfection, the relative expression of APCCD1 mRNA in the experimental group was higher than that in the control group( P < 0. 05). The number of lipid droplets formation and the OD520 value in the experimental group increased as compared with those of the control group( both P < 0. 05). Compared with the control group, the mRNA and protein levels of adipogenic factors, including peroxisome proliferator-activated receptor γ( PPARγ), CCAAT enhancer-binding protein α( C/EBPα), and fatty acid-binding protein 4( FABP4/a P2), increased in the experimental group( all P < 0. 05). As well, the levels of lipogenesis-specific factors, such as fatty acid synthase( FASN), perilipin, and acetyl-coA carboxylase 1( ACC1) increased( all P < 0. 05). Conclusion APCDD1 can promote adipogenic differentiation and lipid synthesis of BMSCs. [ABSTRACT FROM AUTHOR]

The removal efficiencies of ten pesticide residues (carbendazim, imidacloprid, acetamiprid, diethofencarb, propamocarb, profenofos, cypermethrin, triazophos, dichlorvos and pyrimethanil) from cucumber by five different processing methods (washing, boiling, stir-frying, peeling and salting) were investigated under laboratory simulation using LC-MS/MS and GC-MS/MS. The results showed that peeling was the most effective pesticide removal method among these processing methods. Especially, in the cases of profenofos and cypermethrin, the processing factors by peeling were both 0.04. The pesticide removal abilities of other investigated processing methods were in the following order: boiling > stir-frying, washing, and salting. Meanwhile, it was found that the effects of processing methods were directly related to the log Kow of each pesticide. The smaller the log Kow of pesticides, the easier to remove them by washing and boiling. Moreover, we also investigated the time effect of pesticide residue removal with washing, boiling and stir-frying within 10 min. The results showed a decreasing trend of pesticide residue amounts with the increase of treatment time. For all investigated pesticide residues, the processing factors for washing, boiling and stir-frying varied in the region of 1.00-0.62, 0.86-0.37 and 1.13-0.52, respectively, after 10 min treatments. [ABSTRACT FROM AUTHOR]