RESUMEN
A set of coal samples were used for laser-induced breakdown spectroscopy (LIBS) experiment to measure the coal calorific value. Traditional channel normalization method didn't consider the physical / chemical mechanism of coal, which would limit the model in precision, accuracy and repeatability. Thus a new calibrated model based on the kinds of the effects of spectral deviation was proposed in this paper. The model selected 19 groups of coal samples, where the random 15 groups were used to establish quantitative analysis model of calorific value while the remaining four for inspection and evaluation. The model based on spectral deviation factors, and the transmission theory combined with the stark broadening formula was used to deduce the absorption effect mechanism and the deviation correction method under the condition of LIBS. The mutual interference between elements and the mechanism of matrix effect were being analyzed while K coefficient method was used to correct mutual interference between the elements in the LIBS. The establishment of numerical model with the electron density, the plasma temperature and the element concentration was used to deeply corrected spectrum deviation caused by matrix effect. Thus taking into consideration of the effect of self-absorption, interfere of inter-elements and matrix effect, the calibration model was established, while R2=0.967, RMSEP=0.49 MJ·kg-1, RMSE=0.45 MJ·kg-1, MRE=2.42%, ARE=1.64%, RSD=5.79% and RSDP=8.10%. Compared with the 0.405, 8.28 MJ·kg-1, 4.14 MJ·kg-1, 22.85%, 52.48%, 18.28% and 32.85% of traditional channel normalized-multiple linear regression method, it demonstrated that the precision and accuracy have been improved significantly and model has good application value.
RESUMEN
OBJECTIVE: To explore the effect of okra extract on gestational diabetes mellitus (GDM) rats and its probable molecular mechanism. METHODS: A total of 30 female SD rats were caged with male rats for pregnancy, 27 pregnant rats were obtained and weighed. The pregnant rats were equally randomized into the control group, GDM group and intervention group. Once the pregnancy was verified, GDM group and intervention group were given 45 mg/kg streptozotocin by peritoneal injection for inducing GDM, control group was given equal volume of citrate buffer. Once the model was established successfully, intervention group was administered orally the solution containing 200 mg/kg/d okra extract, the other groups were given the diet and water only. On the 19th day of pregnancy, the blood samples and fetal rats of all groups were collected, fetal rats weight and placental weight was recorded and the serum glucose, lipids, serum insulin and C-peptide of pregnant rats before the delivery were determined. RESULTS: The pregnant rats weight before the delivery, fetal rats weight and placental weight of GDM group were lower than control group and intervention group (P < 0.05). After the treatment of okra extract, serum glucose and lipids levels of intervention group were both improved significantly (P < 0.05), especially, the FBG, HDL, FINS, serum m insulin and hepatic glycogen levels were equivalent to control group (P > 0.05). Antioxidant enzymes levels of GDM group in liver and pancreas tissues were lower than the other groups, and after treatment of okra extract, antioxidant enzymes levels in liver and pancreas tissues were equivalent to control group (P > 0.05). CONCLUSIONS: Okra extract, rich in antioxidant substances, could avoid the excessive consuming of antioxidant enzymes, then, suppresses the oxidative stress and insulin resistance, thereby improving blood glucose level of GDM rats.