Ultrasound-assisted dual-cloud point extraction with high-performance liquid chromatography-hydride generation atomic fluorescence spectrometry for mercury speciation analysis in environmental water and soil samples.

A method for simultaneous preconcentration and determination of mercury species in water and soil samples was established using high-performance liquid chromatography with hydride generation atomic fluorescence spectrometry after ultrasound-assisted dual-cloud point extraction. The extraction process was divided into two steps. In the first cloud point extraction, inorganic mercury and methylmercury formed chelates with sodium diethyldithiocarbamate and were extracted into Triton X-114 micelles. In the second stage, a displacement reaction between sodium diethyldithiocarbamate-inorganic mercury/methylmercury and l-cysteine occurred, and the analytes entered the l-cysteine aqueous solution under ultrasonication. This aqueous solution was directly introduced to the high-performance liquid chromatography with hydride generation atomic fluorescence spectrometry and the detection was completed within 6 min. Under the optimum experimental conditions, the linear range was 0.10-5.0 µg/L (r ≥0.9993) for inorganic mercury and methylmercury, and the enhancement factors were 15.7 for inorganic mercury and 6.35 for methylmercury. The limits of detection for inorganic mercury and methylmercury were 0.004 and 0.016 µg/L, respectively. The approach was successfully applied to the determination of trace inorganic mercury and methylmercury in water and soil samples with good recoveries (85.3-110%). This method solved the problem of peak fusion of the two analytes and was successfully applied to the speciation analysis of mercury.

Establishment of a prognostic risk model for prostate cancer based on Gleason grading and cuprotosis related genes.

INTRODUCTION: Prostate cancer (PCa) is common in aging males, diagnosed via the Gleason grading system. The study explores the unexamined prognostic value of cuprotosis, a distinct cell death type, alongside Gleason grades in PCa. METHODS: We explored Cuprotosis-related genes (CRGs) in prostate cancer (PCa), using NMF on TCGA-PRAD data for patient classification and WGCNA to link genes with Gleason scores and prognosis. A risk model was crafted via LASSO Cox regression. STX3 knockdown in PC-3 cells, analyzed for effects on cell behaviors and tumor growth in mice, highlighted its potential therapeutic impact. RESULTS: We identified five genes crucial for a prognostic risk model, with higher risk scores indicating worse prognosis. Survival analysis and ROC curves confirmed the model's predictive accuracy in TCGA-PRAD and GSE70769 datasets. STX3 was a key adverse prognostic factor, with its knockdown significantly reducing mRNA and protein levels, impairing PC-3 cell functions. In vivo, STX3 knockdown in PC-3 cells led to significantly smaller tumors in nude mice, underscoring its potential therapeutic value. CONCLUSION: Our prognostic model, using five genes linked to Gleason scores, effectively predicts prostate cancer outcomes, offering a novel treatment strategy angle.

Interaction studies of sodium cyclamate with DNA revealed by spectroscopy methods.

The interaction between sodium cyclamate (SC) and calf thymus DNA in simulated physiological buffer (pH 7.4) using ethidium bromide (EB) as fluorescence probe was investigated by UV-vis spectrometry (UV), fluorescence, resonance light scattering (RLS) and Fourier transform infrared (FT-IR) spectroscopy, along with DNA melting studies and cyclic voltammetric (CV) measurements. The results indicate that SC can not only bind into the minor groove of DNA, but also intercalate into the DNA Base pairs. Based on UV data, the binding constant K and binding sites n of the formed DNA/SC complex were estimated to be 2.83 × 103 mol/L and 2.0, respectively. Fluorescence results demonstrate that the quenching of DNA/EB induced by SC can mainly be attributed to static procedure. The melting studies and CV analysis further confirm that the interaction mechanism between the SC and DNA is similar to that of DNA intercalator.The results of FT-IR spectra show that a specific interaction mainly exist between SC and adenine and guanine bases of DNA, which resulting in potential damage due to some change in the information structure. The DNA saturation binding value estimated to be 1.67 based on the RLS data also indicated that SC may cause damage of DNA.