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The structure of the electrical double layer has been debated for well over a century, since it mediates colloidal interactions, regulates surface structure, controls reactivity, sets capacitance, and represents the central element of electrochemical supercapacitors. The surface potential of such surfaces generally exceeds the electrokinetic potential, often substantially. Traditionally, a Stern layer of nonspecifically adsorbed ions has been invoked to rationalize the difference between these two potentials; however, the inability to directly measure the surface potential of dispersed systems has rendered quantitative measurements of the Stern layer potential, and other quantities associated with the outer Helmholtz plane, impossible. Here, we use x-ray photoelectron spectroscopy from a liquid microjet to measure the absolute surface potentials of silica nanoparticles dispersed in aqueous electrolytes. We quantitatively determine the impact of specific cations (Li+ , Na+ , K+ , and Cs+ ) in chloride electrolytes on the surface potential, the location of the shear plane, and the capacitance of the Stern layer. We find that the magnitude of the surface potential increases linearly with the hydrated-cation radius. Interpreting our data using the simplest assumptions and most straightforward understanding of Gouy-Chapman-Stern theory reveals a Stern layer whose thickness corresponds to a single layer of water molecules hydrating the silica surface, plus the radius of the hydrated cation. These results subject electrical double-layer theories to direct and falsifiable tests to reveal a physically intuitive and quantitatively verified picture of the Stern layer that is consistent across multiple electrolytes and solution conditions.

Potentiometric titrations have been routinely used to measure the proton-related surface charge density (SCD) of particles in solution. Here, we quantify the SCD of silica nanoparticles (NPs) that are commercially available as charge-stabilized colloids (by the addition of NaOH) in the presence of known amounts of added NaCl. The experimental results are simulated by surface complexation models (SCMs) of the electrical double layer (EDL). The modeling results suggest that involving only the added NaCl electrolyte yields poor agreement between the experiment and the best achievable fit. An increase in the Na concentration accounting for the colloid inherent salt (CIS) associated with these charge-stabilized colloids results in much better simulations. In the available literature, this CIS has often been disregarded. However, in the modeling, the total concentration of Na must be known for a consistent mole balance and derivation of reliable ion-pair binding constants. If the CIS is not accounted for or the original suspensions are not dialyzed, the presence of CIS renders the study of those colloids difficult, particularly when investigating specific ion effects, since the CIS always interferes. In the present work, we show that the SCM-estimated amount of CIS from varying the total salt and solid concentration agrees surprisingly well with the manufacturer specification.

ABSTRACT Introduction: There is a scarcity of population-based prostate cancer survival data in India. We assessed the population-based, overall survival of patients with prostate cancer from the Sangrur and Mansa cancer registries of the Punjab state, India. Methods: In the year 2013-2016, a total of 171 prostate cancer cases were registered in these two registries. Based on these registries, survival analysis was performed using the date of diagnosis as the starting date and the last follow-up date being December 31, 2021 or the date of death. Survival was calculated using STATA software. Relative survival was calculated using the Pohar Perme method. Results: Follow up was available for all the registered cases. Of the 171 cases, 41 (24%) were alive and 130 (76.0%) were dead. Of the prescribed treatments, 106 (62.7%) cases completed the treatment and 63 (37.3%) cases did not complete the treatment. Overall, 5-year age-standardized prostate cancer relative survival was 30.3%. Patients who completed the treatment had a 7.8 times higher 5-year relative survival (45.5%) compared to those who did not (5.8%). The difference between the two groups is statistically significant (hazard ratio 0.16, 95% confidence interval [0.10-0.27]). Conclusion: To improve survival, we need to raise awareness in the community and among primary physicians so that prostate cancer cases can reach the hospital early and should be treated effectively. The cancer center should develop the systems in their hospital so that there will be no hurdles to the patients in treatment completion. We found a low overall relative survival among patients of prostate cancer in these two registries. Patients who received treatment had a significantly higher survival.

In low and middle-income countries, access to cancer diagnosis and treatment is suboptimal. Further, compliance to cancer treatment is a major issue due to various reasons including financial barriers, lack of family support and fear of treatment. This article discusses the determinants of treatment completion in cancer patients of a government-run hospital, in a rural part of Punjab in India. The Sangrur hospital-based cancer registry data for the year 2018 have been used. We have registered 2,969 cancer cases, out of which 2,528 (85%) cases were eligible for the analysis. Of the total 2,528 cases, 1,362 (54%) cases completed the cancer directed treatment and 1,166 (46%) did not. The data have been collected from the electronic medical record (EMR) department and entered into software. The bivariate and multivariate binary logistic regression analysis was performed to see the effect of variables on the treatment completion. The results indicate that the elderly age group (>60 years) (odds ratio (OR): 0.52, (95% confidence interval (CI): 0.31-0.86)), distance from hospital (OR: 0.67, (95% CI: 0.50-0.89)) and access to government health schemes (OR: 0.13, (95% CI: 0.10-0.19)] have direct correlation with the treatment completion. The educated patients (OR: 1.49, (95% CI: 1.13-1.96)) and patients who received curative treatment (OR: 2.7, (95% CI: 1.88-3.88)) have shown 58% and 84% compliance to treatment completion, respectively. The other variables like the clinical extent of disease, religion, gender and income do not have any significant effect on the treatment completion. Determinants like age (young), education, distance from the hospital, curative treatment and availability of government health schemes for financial support have shown positive effects on treatment completion. These factors have to be considered by the cancer hospitals, health departments and policymakers while planning for cancer care or control in India.

Sea-salt aerosols are a source of atmospheric bromine responsible for ozone depletion. The availability of bromine from sea-salt aerosols to heterogeneous phase chemical reactions is determined by its local concentration at the aerosol surface. We report here complete surface segregation of bromine in mixed NaCl/NaBr aerosols grown by drying droplets, thus mimicking the atmospheric process by which solid sea-salt aerosols are generated. For d=70nm solid aerosols, complete surface segregation is observed for solution Br/Cl ratios below 2%. These findings set a size-dependent upper limit on the bromine surface enrichment that can be reached in solid salt aerosols grown from sea-water droplets in the atmosphere.

This study was designed to evaluate the differential effect of epidermal growth factor receptor (EGFR) mutation status (exon 19 vs. 21) on progression-free survival (PFS) and overall survival (OS) in treatment-naïve advanced EGFR mutation-positive nonsmall cell lung cancer (NSCLC) treated with gefitinib as first-line agent. This was a post hoc analysis of EGFR-mutated (exon 19 and 21) advanced-stage (Stage IIIB or IV), chemotherapy-naive NSCLC patients treated with gefitinib as first line in a phase 3 randomized study. Patients were treated with gefitinib 250 mg daily. Patients underwent axial imaging for response assessment on D42, D84, D126, and subsequently every 2 months till progression. Responding or stable patients were treated until progression or unacceptable toxicity. SPSS was used for statistical analysis. Kaplan-Meier method was used for survival estimation and log-rank test for comparison. Cox proportion hazard model was used for multivariate analysis. One hundred and forty-one patients were eligible for analysis, of which 78 were males and 63 were females. A total of 127 patients (90.1%) were ECOG 0-1 while 14 patients (9.1%) were ECOG >1. Exon 21 mutation was present in 65 patients (46.1%) and exon 19 mutation in 76 patients (53.9%). One hundred and thirty-three of 141 patients were evaluable for response. Response rate of patients having exon 19 mutation was 72.9% (51 patients, n = 70) while it was 55.6% in patients having exon 21 mutation (35 patients, n = 63) (P = 0.046). Median PFS in exon 19-mutated patients was 9.3 months (95% confidence interval [CI] 6.832-11.768) compared to 7.8 months (95% CI 5.543-10.0) (P = 0.699) in exon 21-mutated patients. The median OS in exon 19-mutated patients was 19.8 months (95% CI 16.8-22.7), and it was 16.5 months (95% CI 10.9-22.1) in exon 21-mutated patients (P = 0.215). There were no differential outcomes in the Indian patients of advanced-stage NSCLC with exon 19 and 21 EGFR mutations treated with gefitinib.

EGFR mutation subtype is a recognised factor impacting outcomes of patients receiving oral tyrosine kinase inhibitors (TKIs) in non-small-cell lung cancer (NSCLC). Evidence for the effect of this factor on outcomes in patients receiving pemetrexed is limited. We completed a study comparing pemetrexed-platinum combination versus oral TKI in EGFR mutation-positive patients in lung cancer. We analysed the impact of EGFR mutation subtype, specifically, exon 19 and 21 on the PFS and OS of patients treated with pemetrexed (500 mg/m on day 1) and carboplatin (AUC 5 on day 1) as first-line therapy. Patients underwent axial imaging for response assessment on D42, D84, D126 and subsequently every two months till progression. Patients post-progression were treated with gefitinib. Fifty-one patients (36%) had exon 21 mutation, while 92 patients (64%) had exon 19 mutation. Response rates in evaluable patients was 47.7% in exon 19 patients (41 patients, = 86) and 42.9 % in exon 21 patients (18 patients, = 42). There was a significant increase in median overall survival for patients with exon 19 mutations (24.5 months, 95% CI: 21.3-27.7 months ) over the exon 21-mutated patients (18.1 months, 95% Cl: 13.5-22.6 months, = 0.002). This differential impact was due to second-line gefitinib having a differential outcome on these mutations. Pemetrexed-based chemotherapy does not have a differential impact on exon 19- or exon 21-mutated patients. However, second-line treatment with gefitinib has a favourable response and outcome in exon 19-mutated patients.

Abstract Background: There is a paucity of prospective data for patients who progressed after first-line tyrosine kinase inhibitor (TKI) or pemetrexed doublet among epidermal growth factor receptor (EGFR) mutation-positive metastatic non-small cell lung cancer (NSCLC). Aim: The aim of the study was to evaluate the outcome of second-line therapy in patients who progressed on TKI or pemetrexed doublet in EGFR mutation-positive NSCLC. Objective: The objective of the study was to calculate response rates, progression-free survival (PFS), and overall survival (OS) of patients receiving second-line therapy in EGFR mutation NSCLC. Materials and Methods: Post hoc analysis of second-line therapy among patients enrolled in randomized control trial comparing TKI versus pemetrexed doublet in EGFR mutation NSCLC. Kaplan–Meir statistics were used for PFS and OS. Impact of variables was measured with Log-rank test. Results: One hundred and eighty-seven patients who progressed on first-line therapy and received second-line agents were analyzed. Male:female: 110 (56.3%):77 (41.2%). One hundred and thirteen patients received gefitinib, while 74 received chemotherapy. Response rate (complete response + partial response) was 53% versus 24% in gefitinib versus chemotherapy group (RECIST v1.1). PFS was 7.4 months versus 4.4 months ( P = 0.001), while OS was 14 months versus 9.7 months ( P = 0.007), in gefitinib versus chemotherapy group, respectively. Response to TKI significantly improves PFS (10.8 months vs. 3.9 months, P = 0.001) and OS (21.4 months vs. 8.9 months, P = 0.03). Rash, pruritus, dry skin, fatigue, diarrhea, and paronychia were common toxicities of TKI. Conclusion: Second-line TKI improves outcome in EGFR mutation-positive NSCLC who progressed after first-line chemotherapy. Response to therapy, whether with TKI or chemotherapy, favorably impacts outcomes.