Study on the occurrence state of main components of phosphogypsum dihydrate and its impurity distribution.

The dihydrate phosphoric acid process is the mainstream technique. However, the phosphogypsum (PG) produced contains high levels of impurities such as phosphorus and fluorine, severely constraining its valorization. In order to elucidate the occurrence patterns of phosphorus and fluorine impurities in PG, this study employed analytical methods including XRF, XRD, AMICS (Automated Mineralogy Integrated with Chemistry System), XPS, and chemical element balance analysis. We investigated the occurrence states of phosphorus, fluorine, silicon, iron, and aluminum elements in PG from wet-process phosphoric acid production, as well as the distribution characteristics of phosphorus and fluorine impurities. Additionally, we utilized Density Functional Theory (DFT) calculations to determine the binding energies of major minerals with water-soluble phosphate and fluoride groups, and analyzed the zeta potentials of gypsum and quartz mineral surfaces. The results indicate that the main mineral phases in PG are gypsum, quartz, potassium silicate minerals, aluminosilicate minerals, and hematite, predominantly occurring in monomineralic forms. Phosphorus impurities primarily exist in calcium silicate and hematite minerals, while fluorine is mainly associated with gypsum and potassium silicate minerals. DFT calculations demonstrate strong binding energies between calcium silicate and hematite minerals with PO4 3-, as well as between gypsum and quartz minerals with F-. The acidic conditions in the separation tank during wet-process phosphoric acid production may contribute to the distinctive distribution characteristics of phosphorus and fluorine impurities in PG.

Conformational Distributions of Phenyl ß-D-Glucopyranoside and Gastrodin in Solution by Vibrational Optical Activity and Theoretical Calculations.

The conformational landscapes of two highly flexible monosaccharide derivatives, namely phenyl ß-D-glucopyranoside (ph-ß-glu) and 4-(hydroxymethyl)phenyl ß-D-glucopyranoside, also commonly known as gastrodin, were explored using a combined experimental and theoretical approach. For the infrared, Raman, and the associated vibrational optical activity (VOA), i.e., vibrational circular dichroism and Raman optical activity, experiments of these two compounds in DMSO and in water were carried out. Extensive and systematic conformational searches were performed using a recently developed conformational searching tool called CREST (conformer-rotamer ensemble sampling tool) in the two solvents. Fourteen and twenty-four low-energy conformers were identified at the DFT level for ph-ß-glu and gastrodin, respectively. The spectral simulations of individual conformers were done at the B3LYP-D3BJ/def2-TZVPD level with the polarizable continuum model of the solvents. The VOA spectral features exhibit much higher specificity to conformational differences than their parent infrared and Raman. The excellent agreements achieved between the experimental and simulated VOA spectra allow for the extraction of experimental conformational distributions of these two carbohydrates in solution directly. The experimental percentage abundances based on the hydroxymethyl (at the pyranose ring) conformations G+, G-, and T for ph-ß-glu were obtained to be 15%, 75%, and 10% in DMSO and 53%, 40%, and 7% in water, respectively, in comparison to the previously reported gas phase values of 68%, 25%, and 7%, highlighting the important role of solvents in conformational preferences. The corresponding experimental distributions for gastrodin are 56%, 22%, and 22% in DMSO and 70%, 21%, and 9% in water.

Establishment of a 5-gene risk model related to regulatory T cells for predicting gastric cancer prognosis.

BACKGROUND: Gastric cancer (GC) is one of the high-risk cancers that lacks effective methods for prognosis prediction. Therefore, we searched for immune cells related to the prognosis of GC and studied the role of related genes in GC prognosis. METHODS: In this study, we collected the mRNA data of GC from The Cancer Genome Atlas (TCGA) database and studied the immune cells that were closely related to the prognosis of GC. Spearman correlation analysis was performed to show the association between immune cell-related genes and the differentially expressed genes (DEGs) of GC. Univariate and multivariate Cox regression analyses were conducted on the immune cell-related genes with a high correlation with GC. A prognostic risk score model was constructed and the most significant feature genes were identified. Kaplan-Meier method was then used to compare the overall survival (OS) of patients with high-risk and low-risk, and receiver operating characteristic (ROC) analysis was used to assess the accuracy of the risk model. In addition, GC patients were grouped according to the median expression of the features genes, and survival analysis was further carried out. RESULTS: It was noted that regulatory T cells (Tregs) were significantly correlated with the prognosis of GC, and 172 genes related to Tregs were found to be closely associated with GC. An optimal prognostic risk model was constructed, and a 5-gene (including LRFN4, ADAMTS12, MCEMP1, HP and MUC15) signature-based risk score was established. Survival analysis showed significant difference in OS between low-risk and high-risk samples. ROC analysis results indicated that the risk model had a high accuracy for the prognosis prediction of samples (AUC = 0.717). The results of survival analysis on each feature gene based on expression levels were consistent with the results of multivariate Cox analysis for predicting the risk rate of the 5 genes. CONCLUSION: These results proved that the 5-gene signature-based risk score could be used to predict the survival of GC patients, and these 5 genes were closely related to Tregs. These findings are of great significance for studying the role of immune cells and related immune factors in regulating the prognosis of GC.

Association of ERCC1 Polymorphisms with the Risk of Colorectal Cancer: A Meta-Analysis.

The ERCC1 enzyme in the nucleotide excision repair (NER) pathway plays a vital role in DNA repair. Numerous epidemiological studies have evaluated the association between ERCC1 polymorphisms and the risk of colorectal cancer (CRC), with conflicting results. To evaluate the potential associations, we conducted a meta-analysis. Eligible studies were identified by searching electronic databases. The odds ratio (OR) and 95% confidence interval (CI) were applied to assess the associations between ERCC1 polymorphisms and CRC risk. The meta-analysis results revealed significant associations between ERCC1 rs3212986 and rs2298881 polymorphisms and CRC risk (rs3212986 GG vs CC: OR = 1.66, 95% CI = 1.13-2.44; CG vs CC: OR = 1.12, 95% CI = 0.82-1.55; the dominant model: OR = 1.21, 95% CI = 0.86-1.71; the recessive model: OR = 1.59, 95% CI = 1.09-2.31; rs2298881 CC vs. AA: OR = 2.04, 95% CI = 1.29-3.23; AC vs. AA: OR = 1.19, 95% CI = 0.91-1.56; the dominant model: OR = 1.33, 95% CI = 1.04-1.72; the recessive model: OR = 1.91, 95% CI = 1.22-3.00). However, no association with CRC risk was identified for ERCC1 polymorphisms rs11615 and rs2276466. In conclusion, these findings identified no association between rs11615 and rs2276466 polymorphisms and CRC susceptibility, but the data indicate that ERCC1 rs3212986 and rs2298881 polymorphisms may increase susceptibility to CRC. Large and well-designed studies are needed to further validate our findings.

Association between the Epithelial Cadherin - 160C/A Polymorphism and Colorectal Cancer Risk: Evidence from a Meta-Analysis.

The aim of the present study was to assess the association between the epithelial cadherin (CDH1) -160C/A polymorphism and colorectal cancer (CRC) using a meta-analysis. A literature search of PubMed, Embase, and Web of Science databases was performed for relevant studies. Statistical analyses were carried out using Stata 12.0 to combine all of the relevant studies. Odds ratio (OR) with 95% confidence interval (CI) values were applied to evaluate the strength of the association. Eight studies with 7231 cases and 7080 controls were included. The meta-analysis results showed that the CDH1 -160C/A polymorphism was significantly associated with CRC risk (AA vs. CC: OR = 0.98, 95% CI = 0.71-1.36; CA vs. CC: OR = 0.92, 95% CI = 0.86-0.99; dominant model: OR = 1.01, 95% CI = 0.81-1.26; recessive model: OR = 0.91, 95% CI = 0.81-1.02). In the subgroup analysis based on ethnicity, significant association was found between the CDH1 -160C > A polymorphism and CRC risk in Caucasians. In conclusion, the CDH1 -160C/A polymorphism may be a susceptible predictor for the risk of CRC in Caucasians.