Effects and mechanism of igneous rock on selenium in the tropical soil-rice system in Hainan Province, South China

To illuminate the migration and transformation of selenium(Se)in the igneous rock-soil-rice system,285 pairs of rhizosphere soil and rice samples were collected from the granitoid and basalt areas in Hainan Province,South China.The contents of Se in soils derived from granitoid and basalt are,respectively,0.19±0.12 mg/kg and 0.34±0.39 mg/kg,which are much higher than Se contents in granitoid and basalt.Selenium shows remarkable enrichment from granitoid and basalt to soils.The mobile fraction of Se in soils derived from granitoid is 0.0100±0.0034 mg/kg,which is significantly higher than that of basalt(0.0058±0.0039 mg/kg).Although soil derived from basalt shows higher Se contents,Se contents in rice samples,mobile fractions of Se in soils,and biological concentration factor(BCF)is similar or even lower than that from granitoid.Basalt consist of calcic plagioclase and pyroxene,and are much richer in Fe,Al,and Ca than granitoid.Correspondingly,the basalt-derived soils have higher goethite,hematite,kaolinite,cation exchange capacity(CEC)content,and higher p H than the granitoid-derived soils,which result in higher adsorption capacity for Se and relatively lower Se bioavailability.Soils derived from granitoid and basalt in tropical regions are beneficial to produce Se-rich rice.

Moxibustion with different doses for primary dysmenorrhea of cold congelation and blood stasis type:A randomized controlled trial

Objective:To explore the clinical effect differences of moxibustion with different doses on primary dysmenorrhea with cold congelation and blood stasis type.Methods:A total of 60 patients of primary dysmenorrhea were randomized into an intensified dose group and a conventional dose group.All of the patients were treated with moxibustion.In the intensified dose group,the treatment was given three times daily(once every morning,afternoon and at bedtime successively) and during the trial,1 case was dropped out and 29 cases were included in the statistical analysis finally.In the conventional dose group,the treatment was given once daily and 1 case was dropped out during trial and 29 cases were included in the statistical analysis.The score of visual analogue scale(VAS) at the worst painful time point,the score of dysmenorrhea symptoms and recurrence rate were observed and compared before and after treatment in the patients between the two groups.The clinical therapeutic effects were observed in the two groups too.Results:VAS difference value(D-value) and dysmenorrhea symptoms D-valuebefore and after treatment in the intensified dose group were higher than those in the conventional dose group respectively(both P<0.05).The recurrence rate was 14.29% in the intensified dose group,lower than 42.31% in the conventional dose group,with the statistical significance(P<0.05).The total clinical effective rate was 96.55%in the intensified dose group,higher than 89.66% in the conventional dose group,with the statistical significance(P<0.05).Conclusion:Compared with the conventional dose moxibustion,moxibustion with intensified dose achieves satisfactory therapeutic effect on primary dysmenorrhea of cold congelation and blood stasis type.This therapy is low in recurrent rate and convenient in manipulation,thus it deserves to be promoted in clinical application.