Water structure and its influence on the flotation of carbonate and bicarbonate salts

Interfacial water structure is a most important parameter that influences the collector adsorption by salt minerals such as borax, potash and trona. According to previous studies, salts can be classified as water structure makers and water structure breakers. Water structure making and breaking properties of salt minerals in their saturated brine solutions are essential to explain their flotation behavior. In this work, water Structure makin-breaking studies in Solutions of carbonate and bicarbonate salts (Na2CO3, K2CO3, NaHCO3 and NH4HCO3) in 4 wt% D2O in H2O mixtures have been performed by FTIR analysis of the OD stretching band. This method reveals a microscopic picture of the water structure makin-/breakinL, character of the salts in terms of the hydrogen bonding between the water molecules in solution. The results from the vibrational spectroscopic Studies demonstrate that carbonate salts (Na2CO3, K2CO3) act as strong structure makers, whereas bicarbonate salts (NaHCO3 and NH4HCO3) act as weak structure makers. In addition, the changes in the OD band parameters of carbonate and bicarbonate salt solutions are in agreement with the viscosity characteristics of their solutions. (c) 2007 Elsevier Inc. All rights reserved

Water structure and its influence on the flotation of carbonate and bicarbonate salts

Journal of Colloid and Interface Science, 314(2): pp. 545-551.Interfacial water structure is a most important parameter that influences the collector adsorption of salt minerals such as borax, potash and trona. According to previous studies, salts can be classified as water structure makers and water structure breakers. Water structure making and breaking properties of salt minerals in their saturated brine solutions are essential to explain their flotation behavior. In this work, water structure making-breaking studies in solutions of carbonate and bicarbonate salts (Na2CO3, K2CO3, NaHCO3 and NH4HCO3) in 4 wt% D2O in H2O mixtures have been performed by FTIR analysis of the OD stretching band. This method reveals a microscopic picture of the water structure making/breaking character of the salts in terms of the hydrogen bonding between the water molecules in solution. The results from the vibrational spectroscopic studies demonstrate that carbonate salts (Na2CO3 and K2CO3) act as strong structure makers, whereas bicarbonate salts (NaHCO3 and NH4HCO3) act as weak structure makers. In addition, the changes in the OD band parameters of carbonate and bicarbonate salt solutions are in agreement with the viscosity characteristics of their solutions

Gene expression profiling of archived dried blood spot samples from the Danish Neonatal Screening Biobank

A large part of the human genome is transcribed into various forms of RNA, and the global gene expression profile (GEP) has been studied for several years using technology such as RNA-microarrays. In this study, we evaluate whether neonatal dried blood spot (DBS) samples stored in the Danish Neonatal Screening Biobank (DNSB) can be used for GEP.This paper is divided into sub-studies examining the effects of: 1) different whole transcriptome amplification kits (WTA); 2) years of storage and storage in room temperature (RT) versus freezers (-. 20. °C) on DNSB DBS samples; 3) effects of RT storage vs freezer storage on DBS samples from the USA and DNSB, and 4) using smaller disc sizes, thereby decreasing DBS use.We present evidence that reliable and reproducible GEPs can be obtained using neonatal DBS samples. The main source of variation is the storage condition. When samples are stored at -. 20. °C, the dynamic range is increased, and Pearson correlations are higher. Differential analysis reveals no statistically significant differences between samples collected a decade apart and stored at -. 20. °C. However, samples stored at RT show differential expression for a third of the gene-specific probes. Our data also suggests that using alternate WTA kits significantly changes the GEP. Finally, the amount of input material, i.e., the size and number of DBS discs used, can be reduced to preserve this valuable and limited material.We conclude that DNSB DBS samples provide a reproducible resource for GEP. Results are improved if the cards are stored at -. 20. °C. Furthermore, it is important to use a single type of kit for analysis because using alternate kits introduces differential expression

Evaluation of Sex-Specific Gene Expression in Archived Dried Blood Spots (DBS)

Screening newborns for treatable serious conditions is mandated in all US states and many other countries. After screening, Guthrie cards with residual blood (whole spots or portions of spots) are typically stored at ambient temperature in many facilities. The potential of archived dried blood spots (DBS) for at-birth molecular studies in epidemiological and clinical research is substantial. However, it is also challenging as analytes from DBS may be degraded due to preparation and storage conditions. We previously reported an improved assay for obtaining global RNA gene expression from blood spots. Here, we evaluated sex-specific gene expression and its preservation in DBS using oligonucleotide microarray technology. We found X inactivation-specific transcript (<em>XIST</em>), lysine-specific demethylase 5D (<em>KDM5D</em>) (also known as selected cDNA on Y, homolog of mouse (<em>SMCY</em>)), uncharacterized LOC729444 (<em>LOC729444</em>), and testis-specific transcript, Y-linked 21 (<em>TTTY21</em>) to be differentially-expressed by sex of the newborn. Our finding that trait-specific RNA gene expression is preserved in unfrozen DBS, demonstrates the technical feasibility of performing molecular genetic profiling using such samples. With millions of DBS potentially available for research, we see new opportunities in using newborn molecular gene expression to better understand molecular pathogenesis of perinatal diseases