Interpretation of Water Samples by Correspondence Analysis for Radioactive Elements in the Northern Coast of Oman Sea

Oman Sea is connecting belt between the Indian Ocean and Persian Gulf.Because it strategic and environmental aim,presence of natural radionuclide ^(226)Ra,^(232)Th,^(40)K and ^(137)Cs as man-made element is considered.Water samples were taken from 36 marine spots at the coastal strip from Hormoz canyon to Goatr seaport in the northern coast of Oman Sea.Correspondence analysis is used to identify variation and relationship between samples(Q-mood analysis)and variable(R-mood analysis)based on approximate χ^(2)distances.Radioactive elements(^(226)Ra,^(232)Th and^( 40)K),physical(temperature,pH,turbidity,conductivity,special density)and chemical(salinity,oxygen and chlorophyll)parameters of water for 36 samples handled by correspondence analysis,there are two outstanding result,(1)Radioactive elements show high correlation in factors by greater eigenvalue,and (2)some of the samples such as W13,W24 and rather W02,W05 and W12 show highest activity from Radioactive elements and also temperature and conductivity show nearest relation with them in many factors.

Enzyme-Linked Immunosorbent Assay for Detecting Syphilis Dry Blood Spot Samples

Objective:To explore the feasibility of enzyme-linked immunosorbent assay(ELISA)in detecting syphilis dry blood spots.Methods:Based on dry blood spot samples,laboratory linear dial,laboratory basic dial,laboratory interference dial,and laboratory precision dial were constructed.The linear range,sensitivity,specificity,precision and other performances of ELISA for detecting syphilis dry blood spot samples were comprehensively evaluated,and the stability of dry blood spot samples at 37℃was detected.In addition,112 suspected syphilis antibody-positive plasma samples were selected as the control,and dry blood spot samples were prepared accordingly.The clinical sensitivity,clinical specificity,positive predictive value and negative predictive value of dry blood spot samples and plasma samples in ELISA for syphilis detection were compared,and the consistency and correlation between the two samples were analyzed by the Kappa consistency test and Spearman rank correlation analysis.Results:The results of the linear analysis showed that the serial dilution of dry blood spot samples in ELISA for syphilis antibody ranged from 23to 27,and there was a good linear range[R2=0.9862(P<0.05)].Sensitivity and specificity analysis showed that the positive coincidence rate and negative coincidence rate of the two detection methods were 100%(15/15).The results of the interference dial test showed that ELISA based on dry blood spot samples could accurately detect 6 syphilis antibody samples from 18samples,and the detection accuracy rate was 100.00%(6/6).The results of the precision test showed that the RSD of syphilis antibody detection in dry blood spot samples with different dilution times(23,25and 27)was 0.24%to 3.87%between spots,0.06%to4.07%between batches and 0.49%to 3.88%between days.Within 7 days,the inter-day RSD of dry blood spots with different dilution times(23,25,27)were 0.27%,0.65%and 0.95%,respectively.The clinical sensitivity,clinical specificity,positive predictive value and negative predictive value of dry blood spot samples in ELISA detection of syphilis antibody were 96.00%(72/75),100.00%(37/37),100.00%(72/72)and 92.50%,respectively.The results of the Kappa consistency test and Spearman rank correlation analysis showed that the Kappa value of the two methods was 0.941(P<0.01),and the correlation coefficientρbetween the S/CO ratios of the two methods was 0.211(P<0.01).The comparison of S/CO ratio results showed that the distribution characteristics of the S/CO ratio between the two methods were similar,and the ratio distribution was relatively concentrated.Conclusion:using dry blood spot samples to perform ELISA for syphilis detection has good precision,strong anti-interference ability and excellent stability.Although false-positive results appear in weak positive samples,it still has a high application value in ELISA for syphilis antibody detection,which can provide an important reference for disease diagnosis.