ABSTRACT
A rapid quantitative evaluation method for Siraitia grosvenorii cells was successfully developed based on plant cells' capacitance value detected by a viable cell mass monitor and the cryopreservation of S. grosvenorii suspension cells was optimized. The survival rate of S. grosvenorii cells was quantitatively measured by viable cell mass monitor and 2, 3, 5-triphenyltetrazolium chloride (TTC). An optimum cryoprotectant recipe is that the growth medium contained 10% sucrose and 10% DMSO. The experimental results also showed higher cell survival rates and cell viabilities were achieved when suspension cells were treated with pretreatment of 0.2 mol/L sucrose. With the increase of concentration of sucrose, however, the cell survival rate was decreased. And the cell survival rate represented a bell shape with the increase of pretreatment time. The highest cell survival rate and cell viability were obtained with the 9 h' s pretreatment. In addition, there was a good correlation between the cell survival rate measured by cell recovery test and that measured by viable cell mass monitor, while there were no significant differences in the cell morphology and the ability of mogrosides V production by S. grosvenorii cells cultured in suspension after cryopreservation. Therefore, the evaluation method developed based on the viable cell mass monitor has good feasibility and reliability.
ABSTRACT
This paper studies the learning and generalization performances of pseudo-inverse linear discriminant (PILDs) based on the processing minimum sum-of-squared error (MS(2)E) and the targeting overall classification accuracy (OCA) criterion functions. There is little practicable significance to prove the equivalency between a PILD with the desired outputs in reverse proportion to the number of class samples and an FLD with the totally projected mean thresholds. When the desired outputs of each class are assigned a fixed value, a PILD is partly equal to an FLD. With the customarily desired outputs {1, -1}, a practicable threshold is acquired, which is only related to sample sizes. If the desired outputs of each sample are changeable, a PILD has nothing in common with an FLD. The optimal threshold may thus be singled out from multiple empirical ones related to sizes and distributed regions. Depending upon the processing MS(2)E criteria and the actually algebraic distances, an iterative learning strategy of PILD is proposed, the outstanding advantages of which are with limited epoch, without learning rate and divergent risk. Enormous experimental results for the benchmark datasets have verified that the iterative PILDs with optimal thresholds have good learning and generalization performances, and even reach the top OCAs for some datasets among the existing classifiers.
Subject(s)
Datasets as Topic/classification , Linear Models , Algorithms , Databases, Factual/classification , HumansABSTRACT
A rapid and accurate determination method of lipids in microalgae plays a significant role in an efficient breeding process for high-lipid production of microalgae. Using low field nuclear magnetic resonance (LF-NMR), we developed a direct quantitative method for cellular lipids in Chlorella protothecoides cells. The LF-NMR signal had a linear relationship with the lipid content in the microalgae cells for both dry cell samples and algal broth samples (R2 > 0.99). These results indicated that we could use this method for accurate determination of microalgal lipids. Although LF-NMR is a rapid and easy lipid determination method in comparison to conventional methods, low efficiency would limit its application in high throughput screening. Therefore, we developed a novel combined high throughput screening method for high-lipid content mutants of C. protothecoides. Namely, we initially applied Nile red staining method for semi-quantification of lipid in the pre-screening process, and following with LF-NMR method for accurate lipid determination in re-screening process. Finally, we adopted this novel screening method in the breeding process of high-lipid content heterotrophic cells of C. protothecoides. From 3 098 mutated strains 108 high-lipid content strains were selected through pre-screening process, and then 9 mutants with high-lipid production were obtained in the re-screening process. In a consequence, with heterotrophical cultivation of 168 h, the lipid concentration could reach 5 g/L, and the highest lipid content exceeded 20% (W/W), which was almost two-fold to that of the wild strain. All these results demonstrated that the novel breeding process was reliable and feasible for improving the screening efficiency.
Subject(s)
Chlorophyta , Chemistry , Heterotrophic Processes , High-Throughput Screening Assays , Lipids , Magnetic Resonance Spectroscopy , Microalgae , Chemistry , Staining and LabelingABSTRACT
To find the novel hypolipidemic agents, the effects of ursolic acid and artesunate on hyperlipidemia were determined in rats fed a Western-type diet developed a hyperlipidemia. Rats received ursolic acid (50 mg/kg) or artesunate (50 mg/kg) alone, or in combination (25 ± 25 mg/kg and 50 ± 50 mg/kg), to prevent hyperlipidemia. Ursolic acid or artesunate alone significantly decreased the plasma triglyceride, but had no effect on the levels of cholesterol. The combination of ursolic acid and artesunate can reduce both triglyceride and cholesterol, and the effects were more potent than either agent alone, which indicates a strong synergistic effect. The hypolipidemic effect of artesunate is firstly reported. Its combination with ursolic acid might have the potential to further develop for the treatment of hyperlipidemia.
Subject(s)
Artemisinins/pharmacology , Cholesterol/blood , Hyperlipidemias/blood , Hypolipidemic Agents/pharmacology , Triglycerides/blood , Triterpenes/pharmacology , Animals , Artesunate , Atorvastatin , Disease Models, Animal , Heptanoic Acids/pharmacology , Pyrroles/pharmacology , Rats , Ursolic AcidABSTRACT
Objective To observe the effect of different doses unilateral and compound of artesunate and ursolic acid on lipid metabolism in rats′model, find out the best ratio of artesunate and ursolic acid .Methods Lipid metabolism disorders model was in-duced by feeding high fat diet in rat .The best ratio was screened through comparing the lipid level of rats ofdifferent groups .Results The results showed that Artesunate ( high dose ) +Ursolicacid ( high dose ) significantly reduced TG , CHO and LDL-C, increased HDL-C and H/L.Lipid-lowering effect was superior the positive drug fenofibrate , but also superior to the same dose of artesunate and ursolic acid alone.No significant effect of each test sample on the rat liver function was observed (P>0.05).Conclusion Artesunate and ursolic acid ratio of 1:1 had the best lipid-lowering effect, and the recommended dose was (50+50) mg/kg.
ABSTRACT
Aim To evaluate neuroprotective effects of stearic acid on primarily cultured hippocampal neurons and to study the mechanism of neuroprotection afforded by stearic acid.Methods Primarily cultured hippocampal neurons were insulted by OGD(oxygen-glucose deprivation),H_2O_2,glutamate and NaN_3;MTT assay was utilized to evaluate cell viability;Inhibitors of PPAR?and PI-3K signal pathway were used to study mechanisms of neuroprotection of stearic acid.Results Compared with control neurons,A_(570) in MTT assay were increased significantly by stearic acid in hippocampal neurons insulted by OGD(oxygen-glucose deprivation),H_2O_2 and glutamate(P
ABSTRACT
Objective To investigate the neuroprotective effect of panaxynol on primary cultured cortical neuron against oxidative stress. Methods Viability of panaxynol acted on neuron oxidative stress was monitored by MTT assay and FCM method. Scavenging effects of panaxynol on free radicals were observed in vitro. Effects of panaxynol on SOD activity and GSH-Px, and MDA content in primary neuron injured by H_2O_2 were also determined. Results Panaxynol (2—16 ?mol/L) could dose-dependently protect neuron from oxidative stress induced by H_2O_2; 8 ?mol/L of panaxynol could decrease necrosis and apoptosis rate of neuron significantly (P
