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The energy adjustment models in nutritional epidemiological studies could substantially reduce the confounding effect of total energy intake from the intake of dietary components, and it could explore the real relationship between the intake of dietary component and research outcomes. Four energy adjustment models were introduced in this article, including the standard multivariate model, multivariate nutrient residual model, energy partition model, and multivariate nutrient density model. The four energy adjustment models were applied to analyze the association between the intake of saturated fatty acids and the risk of all-cause mortality based on the data of the US National Health and Nutrition Examination Survey. The consistent results of different energy adjustment models could indicate that the four models could better control the confounding effect of total energy intake.
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Objective To establish the degree of gray incidence model of Gentiana officinalis H.Smith. from differenct producing areas of Gansu Province and conduct quality evaluation. Methods Ten samples of Gentiana officinalis H.Smith. from different producing areas in Gansu Province were collected and the gentiopicroside, total iridoid gycoside, extractives, total ash, acid-insoluble ash content of Gentiana officinalis H.Smith were tested. The quality evaluation of grey incidence model of Gentiana officinalis H.Smith. was established by grey incidence model. Results The relative correlation degrees of all evaluation items were in the range of 0.394–0.652. Among them, the relative correlation degree of samples from 6 producint areas were greater than 0.50, which had high quality evaluation. The relative correlation degrees of the rest samples from other producing areas were less than 0.50, which had low quality evaluation. The sample of Gentiana officinalis H.Smith. from Zhuoni County Liulin Township Observatory had the most highly correlated with the optimal reference sequence (0.652) and so the best in quality;The sample of Gentiana officinalis H.Smith. from Zhang County Sancha Town Langwang Ditch had the most lowly correlated with the optimal reference sequence (0.394) and so the worst in quality. Conclusion This method and quality evaluation model can be used for the quality evaluation for Gentiana officinalis H.Smith., which can provide acertain experimental basis for the development and utilization of new resources.
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Objective To study the ultrasonic extraction technology of tyrosol in Rhodiolae Crenulatae Radix et Rhizoma;To mathematically simulate the extraction process.Methods The content of tyrosol was set as index;HPLC was used;the ultrasonic extraction process of tyrosol in Rhodiolae Crenulatae Radix et Rhizoma was optimized by an orhogonal experiment and mathematic simulation.Results The optimum ultrasonic extraction conditions were as follows:80%ethanol was used as extraction solvent, the ratio of material to liquid was 1:35 (g:mL), with the extraction time of 30 min and ultrasonic power of 240 W. In these conditions, the extracting rate of tyrosol was 0.150 1%. Compared with the heating reflux method, the extraction time should be shortened by 66.7% and the extracting rate should be increased by 12%.Conclusion The extraction method is simple and the extraction rate of effective components is high. Mathematical simulation values based on ultrasonic extraction are consistent with experiment values.
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OBJECTIVE:To optimize the ultrasonic extraction technology of salidroside in Rhodiola rosea. METHODS:With the content of salidroside as the index,L16(45)orthogonal test was designed to observe the effects of 4 factors including the mass fraction of ethanol,solid-liquid ratio,extraction time and ultrasonic power on the content of salidroside in R. rosea extraction solu-tion. By using Matlab 6.5 software,mathematical simulation of ultrasonic extraction process of salidroside was made with the data of orthogonal test. Multiple regression analysis method was adopted to optimize the ultrasonic extraction technology of salidroside, and then the extraction result of optimal technology and that of traditional heating reflux technology were compared. RESULTS:The optimal extraction technology of salidroside was as follows as ethanol mass fraction of 77%,solid-liquid ratio of 1∶34 (g∶ml),extraction time of 34 min,ultrasonic power of 237 W(ultrasonic frequency of 40 kHz). Under the above-mentioned condi-tions,the content of salidroside was up to 0.982 4%,close to the predicted value of 0.989 4%. Compared to heating reflux meth-od,the ultrasonic method has similar content of salidroside but extraction time was shortened by 62.2%. CONCLUSIONS:The ul-trasonic extraction method for extracting the salidroside in R. rosea is simple,requires shorter time,and giving rise to higher extrac-tion rate.
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The paper is to report the establishment of three methods for determination of methyl salicylate-2-O-beta-D-galactopyranoside (1-4)-beta-D-glucopyranoside (MSG) by HPLC, UV or potentiometric titration. The results determined by the three methods turned out to be of no significant difference (P>0.05). The method was chosen according to MSG difference test demands.
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<p><b>OBJECTIVE</b>To study the chemical constituents from the leaves of Sterculia foetida.</p><p><b>METHOD</b>Compounds were isolated by chromatographic techniques. Their structures were elucidated by spectroscopic methods.</p><p><b>RESULT</b>Eight compounds were identified as 5,7,8-tetrahydroxy-4'-methoxyflavone-8-O-beta-D-glucoside (1), 5,7,8-tetrahydroxy-4'-methoxyflavone-7-O-beta-D-glucoside (2), quercetin-3-O-beta-D-glucoside (3), apigenin-6, 8-di-C-beta-D-glucoside (4), puerarin (5), 5,7,8,3'-tetrahydroxy-4'-methoxyflavone (6), 5,7,8-tetrahydroxy-3',4'-dimethoxyflavone (7), 5,7,8-tetrahydroxy-4'-methoxyflavone (8).</p><p><b>CONCLUSION</b>Compounds 1, 2 and 4-8 were isolated from this plant for the first time.</p>