Investigation of type of interaction between salicylic acid and ethanol at different temperatures.

ABSTRACT The study of ultrasonic velocity leads to a better understanding of the nature of interactions between the solute and solvent. Density, viscosity and ultrasound velocity have been determined over the complete concentration range for binary liquid mixture of salicylic acid and ethanol. These data provide useful information about various types of interactions occurring in the solution. The derived acoustic parameters like adiabatic compressibility, intermolecular free length, specific acoustic impedance etc. Have been calculated from experimental data. The sign and magnitude of these properties have been used to interpret the experimental results in terms of molecular interactions

THE SOLVOLYTIC STUDY OF LANTHANUM CHLORIDE IN AQUEOUS ACETIC ACID

ABSTRACT The ion solvent interaction between lanthanum chloride and aqueous acetic acid was studied with the help of ultrasonic velocity and other parameters (like isentropic compressibility, specific acoustic impedance, inter molecular free length, specific acoustic impedance and relative association) determined by using a single crystal interferometer at a frequency of 2 MHz at 30, 35, and 40 ο C. The results indicate that there is a significant interaction between solute and solvent

Liquid-Liquid Phase Separation of Histone Proteins in Cells: Role in Chromatin Organization

Liquid-liquid phase separation (LLPS) of proteins and nucleic acids has emerged as an important phenomenon in membraneless intracellular organization. We demonstrate that the linker histone H1 condenses into liquid-like droplets in the nuclei of HeLa cells. The droplets, observed during the interphase of the cell cycle, are colocalized with DNA-dense regions indicative of heterochromatin. In vitro, H1 readily undergoes LLPS with both DNA and nucleosomes of varying lengths but does not phase separate in the absence of DNA. The nucleosome core particle maintains its structural integrity inside the droplets, as demonstrated by FRET. Unexpectedly, H2A also forms droplets in the presence of DNA and nucleosomes in vitro, whereas the other core histones precipitate. The phase diagram of H1 with nucleosomes is invariant to the nucleosome length at physiological salt concentration, indicating that H1 is capable of partitioning large segments of DNA into liquid-like droplets. Of the proteins tested (H1, core histones, and the heterochromatin protein HP1 alpha), this property is unique to H1. In addition, free nucleotides promote droplet formation of H1 nucleosome in a nucleotide-dependent manner, with droplet formation being most favorable with ATP. Although LLPS of HP1 alpha is known to contribute to the organization of heterochromatin, our results indicate that H1 also plays a role. Based on our study, we propose that H1 and DNA act as scaffolds for phase-separated heterochromatin domains

To study the effect of pterygium excision on corneal curvature and contrast sensitivity

Introduction: To evaluate the corneal astigmatism and contrast sensitivity before and after pterygium surgery and to study the relationship between amount of astigmatism and contrast sensitivity in various grades of pterygia. Material and Method: Sixty three eyes of 63 patients with primary pterygia were studied before and after surgery. The astigmatism induced by primary pterygium was measured by manual keratometer and contrast sensitivity by Pelli Robson chart. Preoperative and postoperative values were compared using paired t –test and ANOVA test. Result: Astigmatism decreased significantly following pterygium excision. The mean preoperative refractive cylinder decreased from 3.29±1.46 D to 1.49±0.82 D postoperatively. Surgical removal of pterygium caused a significant reduction in refractive astigmatism. The amount of astigmatism decreased significantly following pterygium excision in grade II , grade III and in grade IV. In grade I pterygium, decrease in the amount of astigmatism was not statistically significant (p=0.515). The contrast sensitivity increased significantly following pterygium excision. The mean preoperative contrast sensitivity increased from 1.49±0.21 to 1.70±0.20 postoperatively. Surgical removal of pterygium caused a significant improvement in contrast sensitivity. Conclusions: Surgical excision of pterygium improves contrast sensitivity, visual acuity and reduces astigmatism. Contrast sensitivity testing may provide additional objective methods for documenting impaired vision in patients with pterygium when Snellen visual acuity is minimally affected. Corneal astigmatism and contrast sensitivity values in patients with pterygia are useful indicators for the need of pterygium surgery or as indicators of surgical success

SARS-CoV-2 vaccination modelling for safe surgery to save lives: data from an international prospective cohort study

Background Preoperative SARS-CoV-2 vaccination could support safer elective surgery. Vaccine numbers are limited so this study aimed to inform their prioritization by modelling. Methods The primary outcome was the number needed to vaccinate (NNV) to prevent one COVID-19-related death in 1 year. NNVs were based on postoperative SARS-CoV-2 rates and mortality in an international cohort study (surgical patients), and community SARS-CoV-2 incidence and case fatality data (general population). NNV estimates were stratified by age (18-49, 50-69, 70 or more years) and type of surgery. Best- and worst-case scenarios were used to describe uncertainty. Results NNVs were more favourable in surgical patients than the general population. The most favourable NNVs were in patients aged 70 years or more needing cancer surgery (351; best case 196, worst case 816) or non-cancer surgery (733; best case 407, worst case 1664). Both exceeded the NNV in the general population (1840; best case 1196, worst case 3066). NNVs for surgical patients remained favourable at a range of SARS-CoV-2 incidence rates in sensitivity analysis modelling. Globally, prioritizing preoperative vaccination of patients needing elective surgery ahead of the general population could prevent an additional 58 687 (best case 115 007, worst case 20 177) COVID-19-related deaths in 1 year. Conclusion As global roll out of SARS-CoV-2 vaccination proceeds, patients needing elective surgery should be prioritized ahead of the general population.The aim of this study was to inform vaccination prioritization by modelling the impact of vaccination on elective inpatient surgery. The study found that patients aged at least 70 years needing elective surgery should be prioritized alongside other high-risk groups during early vaccination programmes. Once vaccines are rolled out to younger populations, prioritizing surgical patients is advantageous