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A PP plastic film for food packaging (0. 1 mm) was prepared by adding two antioxidants of 2,6-di-tert-butyl-4-methyl-phenol(BHT) and pentaerythritol tetrakis ( 3-( 3, 5-di-tert-butyl-4-hydroxyphenyl ) propionate)(Irganox 1010) with different concentrations into polypropylene (PP) resin, then mixing extrusion granulate by the double screw plastic extruder and hot pressing the film at 190℃. The migration amount of the two antioxidants in food simulants (95% ethanol) was determined by high performance liquid chromatography (HPLC) with diode array detector (PDA) (detection wavelength is 282 nm). The migration of BHT was detected and Irganox 1010 was not detected. Based on the large amount of experimental data, the migration model was fitted by a software, then the migration model of antioxidant BHT was established, the applicability of the two migration model was compared with the actual data. The results showed that the fitting degree ( R2 ) of Weibull model to the actual migration result was greater than 0. 99 and better than Piringer model. It was found that there was a mathematical relationship as τ≈12. 2 ( L2/D) between parameters of Weibull model and Piringer model.
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Background and purpose:Urothelial carcinoma of the bladder (UCB) is the most common cancer in urinary system. Yes associated protein (YAP) gene is closely associated with urothelial carcinoma of the bladder. The study was aimed to explore the effect of siRNA targeting the YAP gene on cell proliferation and migration of T24 cells. Methods:Small interfering RNA (siRNA) was transfected together with LipofectamineTM2000 in T24 human bladder cancer cells to block the YAP signal pathway. The effect of siRNA on cell proliferation and invasiveness was assessed by cell counting kit-8 (CCK-8) assay, Transwell migration assay and wound healing assay. Quantitative real time-Polymerase chain reaction (qRT-PCR) and Western blot analysis were used to conifrm the successful suppression of YAP gene and protein by siRNA. Results:Expression of YAP gene and protein was successfully suppressed after transfected with siRNA which verified by qRT-PCR and Western blot(RNA:F=93.91, P<0.000 1; Protein: F=4.62, P<0.05). As CCK-8 test showed, the proliferation of T24 bladder cancer cells was successfully restrained by inhibition of YAP gene compared with blank control and negative control(12 h: F=6.00, P=0.037;24 h: F=41.72, P=0.000 3;36 h:F=462.8, P<0.000 1;48 h:F=236.6, P<0.000 1;72 h:F=140.5, P<0.000 1). Transwell and wound healing test were performed after YAP gene was interfered by siRNA. The result demonstrated that migration of T24 bladder cancer cells was signiifcantly inhibited (Transwell: F=43.55, P<0.05;Wound healing: F=43.55, P<0.05). Conclusion:This study suggested that YAP gene was an important enhancer for the proliferation and migration of bladder cancer cells.
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In order to improve the stationary phase retention of polar solvent systems and aqueous two-phase systems (ATPSs), we designed a multiple spiral disk assembly for type-J high-speed counter-current chromatography (HSCCC). The stationary phase retention was studied under different elution modes by using two solvent systems that contained 1-butanol-acetic acid-water (4:1:5, V/V/V) and polyethylene glycol (PEG) 1000-K2HPO4-water (12.5:12.5:75, W/W/W). The best retention was obtained in L-I-T, U-O-H, L-I-H three modes by pumping lower mobile phase from inner terminal (I) to outer terminal (O), and upper mobile phase from outer terminal (O) to inner terminal (I) at a relatively high flow rate. Meanwhile, the relationship between retention percentage of the stationary phase (Sf) and various parameters such as flow-rate (F), rotation speed (w) and column temperature (T) was also studied. Sf increased with the increase of w and decreased with the increase of F. Regression analysis showed a linear relationship between Sf and F1/2/w. The influence of T on Sf was not obvious between 20 degrees C and 40 degrees C, lower temperature than 20 degrees C was not suitable for viscous ATPSs. Acceptable resolutions were achieved when it was applied for the separation of dipeptides including Leu-Tyr and Val-Tyr by using 1-butanol-acetic acid-water (4:1:5, V/V/V) solvent system. The proteins including cytochrome C and myoglobin, lysozyme and myoglobin, and fresh chicken egg-white proteins were well separated by 12.5% PEG1000-12.5% K2HPO4-75% water (pH 9.0) and 16% PEG 1000-12.5% K2HPO4-71.5% water (pH 8.0) system.
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Distribuição Contracorrente , Métodos , Peptídeos , ProteínasRESUMO
To investigate hypoglycemic substances from pumpkin, protein-bound polysaccharide was isolated by activity-guided isolation from water soluble substances of the fruits. The protein-bound polysaccharide from pumpkin fruits (PBPP) was identified to consist mainly of polysaccharide (approximately 41.21%) and protein (approximately 10.13%) by anthrone test and Lowry-Folin test. Different doses of PBPP were evaluated for hypoglycemic activity and the effect on serum insulin levels in alloxan diabetic rats. The results indicated that PBPP can obviously increase the levels of serum insulin, reduce the blood glucose levels and improve tolerance of glucose. The hypoglycemic effect of big dose PBPP group (1000 mg/kg body weight) excelled that of small dose PBPP group (500 mg/kg body weight) and antidiabetic agent group. The results suggest that the hypoglycemic effect of PBPP depends on the dose and PBPP possesses the possibility of being developed from a new antidiabetic agent.