The solubility of quartz in the aqueous sodium chloride solution at high temperatures and high pressures

The solubility of quartz in the aqueous solutions of 1, 3 and 7% sodium chloride concentration was measured at the temperatures up to 500℃ and at the packing ratios from 1/3 to 1/1.6ml/ml by observing the loss in the weight of quartz blocks in contact with the solution. The solubility of quartz in sodium chloride solution was larger than in water at temperatures above 280℃, and rose more rapidly with temperature than in water. Reproducible values were not always obtained at temperatures above 340℃ to the critical temperature in the same conditions, and the solubility values were roughly classified into three groups, higher, lower and intermediate. The results under supercritical conditions being considered as the effect of sodium chloride on the solubility of quartz in steam, it is shown that the smaller the density of steam is, the larger the effect of sodium chloride, and the effect can not be found when the density is sufficiently large. As the results the author gave some consideration on the effect. of sodium chloride on the equilibrium in the quartz-water system

The solubility of quartz in water at high temperatures ans high pressures

The solubility of quartz in water was measured at the temperature range up to 500℃ and at the pressure range up to 900 atm by observing the loss in the weight of quartz blocks in contact with water. The measurements were made along the three-phase boundary, quartz-gas-liquid, and in the two-phase field, quartz-gas, under supercritical conditions. The present values are generally lower than those already published, and the maximum value for the discrepancy is about 10 per cent. The solubility is proportional to the fugacity under supercritical conditions except the portion under higher pressures at temperatures below 420℃, provided that the temperature is kept constant

The polymerization of silicic acid obtained by the hydrothermal treatment of quartz and the solubility of amorphous silica

The polymerization of silicic acid in the solution obtained by treating quartz with water at temperature 400℃ and under a specific volume of water 1.6ml/g was investigated from the changes in the concentration of molecular silica, the results were compared with those already reported, in which the silicic acid prepared from sodium silicate solution was used. The rate of the polymerization of silicic acid showed the maximum at about pH 7.5, and became lower on the both sides of this pH. The polymerization reaction seemed to be the second order on the acid side and the third order on the alkaline side with respect to the concentration of molecular silica. The effect of temperature was observed at temperatures from 0 to 100℃, and it was ascertained that the rate of the polymerization increased with temperature. The activation energy was estimated to be 9.8 kcal/mol in the original solution (pH 6.0). The solubility curve of amorphous silica was obtained by determining the concentrations of monomeric silica in the equilibrium state of polymerization, and the results were compared with those already obtained by the author and his co-worker and others. The heat of solution of amorphous silica was estimated to be 3.2kcal/mol

The solubility equilibrium and the rate of solution of quartz in water at high temperatures and high pressures

The reasonable chemical equilibrium for solution of quartz in water under supercritical conditions seems to be represented by the following equation: SiO_2(quartz)+2H_20(gas)⇄Si(OH)_4(gas). The constants K_f and K_e for this equilibrium were calculated using the data already published by the author. From a comparison of K_e as a function of temperature, the heat of solution ΔE was estimated to be 7.80 kcal/mol. The changes in the amount of dissolved quartz were measured by the quenching method at temperatures 400, 440 and 480℃ and under specific volumes of solvents, 3.0, 2.0 and 1.6ml/g. The following rate equation was found to be applied to the solution of quartz under supercritical conditions: -dC/dt=kS(Ce-C)/Ce, where k is the rate constant, C, the concentration of monosilicic acid (Ce at equilibrium) and S, the constant for the surface of quartz. The rate of solution was accelerated by sodium chloride added to water

High HER2 Intratumoral Heterogeneity Is a Predictive Factor for Poor Prognosis in Early-Stage and Locally Advanced HER2-Positive Breast Cancer

Purpose: Breast cancer tumors frequently have intratumoral heterogeneity (ITH). Tumors with high ITH cause therapeutic resistance and have human epidermal growth factor receptor 2 (HER2) heterogeneity in response to HER2-targeted therapies. This study aimed to investigate whether high HER2 heterogeneity levels were clinically related to a poor prognosis for HER2-targeted adjuvant therapy resistance in primary breast cancers. Methods: This study included patients with primary breast cancer (n = 251) treated with adjuvant HER2-targeted therapies. HER2 heterogeneity was manifested by the shape of HER2 fluorescence in situ hybridization amplification (FISH) distributed histograms with the HER2 gene copy number within a tumor sample. Each tumor was classified into a biphasic grade graph (high heterogeneity [HH]) group or a monophasic grade graph (low heterogeneity [LH]) group based on heterogeneity. Both groups were evaluated for disease-free survival (DFS) and overall survival (OS) for a median of ten years of annual follow-up. Results: Of 251 patients with HER2-positive breast cancer, 46 (18.3%) and 205 (81.7%) were classified into the HH and LH groups, respectively. The HH group had more distant metastases and a poorer prognosis than the LH group (DFS: p p = 0.012 (HH:78% vs. LH:95% at 10 years). Conclusions: High HER2 heterogeneity is a poor prognostic factor in patients with HER2-positive breast cancer. A novel approach to heterogeneity, which is manifested by the shape of HER2 FISH distributions, might be clinically useful in the prognosis prediction of patients after HER2 adjuvant therapy