ABSTRACT
Background: Thyroid dysfunction is associated with the risk of benign and malignant breast tumors, but currently there is a lack of model studies to demonstrate the predictive role of thyroid dysfunction in benign and malignant breast tumors. This study aims to establish a model for predicting the association between thyroid dysfunction and breast cancer. Methods: This retrospective study enrolled breast tumor patients from the Affiliated Tumor Hospital of Xinjiang Medical University from 2015 to 2019. Their baseline data and laboratory data were collected. Python was used for data processing and analysis. Data preparation, feature selection, model construction, and model evaluation were conducted. We utilized the classification probabilities generated by the model as scores and further conducted a least absolute shrinkage and selection operator analysis. Results: Analysis of the laboratory data revealed statistically significant differences in thyroid-stimulating hormone, thyroxine, free thyroxine, free triiodothyronine, and thyronine levels between patients with benign and malignant tumors. Based on age, ethnicity, thyroid function, and estrogen levels, the predictive model for breast tumor malignancy indicated that the factors with the greatest importance ranking were age > follicle-stimulating hormone > luteinizing hormone > prolactin > thyroxine > testosterone > ethnicity. The model showed an accuracy rate of 83.70%, precision of 90.69%, sensitivity of 84.74%, and specificity of 81.50%. The area under the receiver operating characteristic curve was 0.9012, close to 1, indicating good predictive performance of the model. Conclusions: The predictive model based on factors such as age, ethnicity, thyroid function, and estrogen levels performs well in predicting the occurrence and development of benign and malignant breast tumors.
ABSTRACT
In this paper, a method of determination of trace lead in water by UV-Visible diffuse reflectance spectroscopy combined with surfactant and membrane filtration enrichment was proposed. In the NH3 x H2O-NH4Cl buffer solution with pH 8.5, the lead(II) ion would react with dithizone to form the red complex under vigorous stirring, which is hydrophobic and can be enriched by the mixed cellulose ester membrane. In addition, the nonionic surfactant Polyoxyethylene lauryl ether (Brij-30) was added into the solution to improve the enrichment efficiency, then visible diffuse reflectance spectra of the membrane were measured directly after the membrane were naturally dried. We also optimized the reaction conditions which may affect the complexation reaction process, such as type of surfactants, the concentration of the surfactant, the reaction acidity, the concentration of dithizone as well as the reaction time. The research results show that under the optimum conditions, a good linear correlation between absorbance at 485 nm and concentration of lead in the range of 5.0-100.0 microg x L(-1) was obtained with a squared correlation coefficient (R2) of 0.9906, and the detection limit was estimated accordingly to be 2.88 microg x L(-1). To determine real water sample, the interference from some potential coexisting ions was also studied at the optimal conditions when the concentration of lead (II) ion standard solution was fixed to 20 microg x L(-1). The results indicate that the following ions cannot interfere in the determination of lead with the proposed method: 500 times of the K+, Na+, Ca2+, Mg2+, NH4+, NO3-, Cl-, CH3COO-, SO4(2-); 10 times of the Al3+ (using 10% NaF as a masking reagent to avoid the interference); 10 times of the Fe3+ (using 10% NaF and 10% sodium potassium tartrate as masking reagents); 10 times of Hg2+ or Zn2+ (using 10% NaSCN and 10% potassium sodium tartrate as masking reagents); the same amount of Cd2+, Cu2+. The proposed method was applied to the determnation of lead (II) in bottled water as a real sample. The determination results show good agreements between the proposed method and graphite furnace atomic absorption spectrometry (GFAAS) method. The recoveries in case of spiked real samples were between 95.4% and 104.5%, and the standard deviations (SD) were between 0.5 micro x L(-1) and 1.5 microg x L(-1), which indicate that the method developed in the present work with advantages of accuracy, simpleness, sensitiveness are of potential application for the determination of trace lead in water samples.
ABSTRACT
A simple, sensitive and selective solid phase reflectometry method is proposed for the determination of trace mercury in aqueous samples. The complexation reagent dithizone was firstly injected into the properly buffered solution with vigorous stirring, which started a simultaneous formation of nanoparticles suspension of dithizone and its complexation reaction with the mercury(II) ions to make Hg-dithizone nanoparticles. After a definite time, the mixture was filtered with membrane, and then quantified directly on the surface of the membrane by using integrating sphere accessory of the UV-visible spectrophotometer. The quantitative analysis was carried out at a wavelength of 485 nm since it yielded the largest difference in diffuse reflectance spectra before and after reaction with mercury(II).A good linear correlation in the range of 0.2-4.0 µg/L with a squared correlation coefficient (R(2)) of 0.9944 and a detection limit of 0.12 µg/L were obtained. The accuracy of the method was evaluated by the analysis of spiked mercury(II) concentrations determined using this method along with those determined by the atomic fluorescence mercury vapourmeter and the results obtained were in good agreement. The proposed method was applied to the determination of mercury in tap water and river water samples with the recovery in an acceptable range (95.7-105.3%).
