Quantifying the Influence of Electrolytes on the Kinetics of Spontaneous Emulsification.

This study quantifies the influence of electrolytes on the kinetics of the spontaneous emulsification phenomenon (SEP) of heavy hydrocarbons in a nonionic surfactant solution. The rate of emulsifying hexadecane in Triton X-100, with the presence of sodium chloride and potassium chloride, has been measured using a technique of monitoring single oil droplet photography. The emulsion droplet size produced in the process was measured under the same conditions by using dynamic light scattering. The data obtained from the two experiments were employed to investigate the mass transfer coefficient of the surfactant molecules through the intermediate layer formed between hexadecane and the surfactant solution. It was found that the electrolytes in an aqueous solution increase the surfactant diffusion rate through the intermediate layer and reduce the emulsion droplet size. As a result, both electrolytes reduce the rate of spontaneous emulsification, with potassium chloride having a more substantial reduction. A model was developed to quantify the influence of electrolytes on the kinetics of the SEP. The data and modeling results verify the influence of ions on the kinetics of spontaneous emulsification. The results provide a significant foundation for predicting the solubilization of heavy hydrocarbons in an electrolyte solution.

Synthesis of a Grease Thickener from Cashew Nut Shell Liquor.

Thickener, also known as a gelling agent, is a critical component of lubricating greases. The most critical property of thickener, temperature resistance, is determined by the molecular structure of the compounds. Currently, all high-temperature-resistant thickeners are based on 12-hydroxystearic acid, which is exclusively produced from castor oil. Since castor oil is also an important reagent for other processes, finding a sustainable alternative to 12-hydroxystearic acid has significant economic implications. This study synthesises an alternative thickener from abundant agricultural waste, cashew nut shell liquor (CNSL). The synthesis and separation procedure contains three steps: (i) forming and separating calcium anacardate by precipitation, (ii) forming and separating anacardic acid (iii) forming lithium anacardate. The obtained lithium anacardate can be used as a thickener for lubricating grease. It was found that the recovery of anacardic acid was around 80%. The optimal reaction temperature and time conditions for lithium anacardate were 100 °C and 1 h, respectively. The method provides an economical alternative to castor and other vegetable oils. The procedure presents a simple pathway to produce the precursor for the lubricating grease from agricultural waste. The first reaction step can be combined with the existing distillation of cashew nut shell processing. An effective application can promote CNSL to a sustainable feedstock for green chemistry. The process can also be combined with recycled lithium from the spent batteries to improve the sustainability of the battery industry.

Comparison between Cashew-Based and Petrochemical Hydroxyoximes: Insights from Molecular Simulations.

Solvent extraction has been ubiquitously used to recover valuable metals from wastes such as spent batteries and electrical boards. With increasing demands for energy transition, there is a critical need to improve the recycling rate of critical metals, including copper. Therefore, the sustainability of reagents is critical for the overall sustainability of the process. Yet, the recycling process relies on functional organic compounds based on the hydroxyoxime group. To date, hydroxyoxime extractants have been produced from petrol-based chemical feedstocks. Recently, natural-based cardanol has been used to produce an alternative hydroxyoxime. The natural-based oxime has been employed to recover valuable metals (Ga, Ni, Co) via a liquid/liquid extraction process. The natural compound has a distinctive structure with 15 carbons in the alkyl tail. In contrast, petrol-based hydroxyoximes have only 12 or fewer carbons. However, the molecular advantages of this natural-based compound over the current petrol-based ones remain unclear. In this study, molecular dynamics simulation was employed to investigate the effect of extractant hydrocarbon chains on the extraction of copper ions. Two hydroxyoxime extractants with 12 and 15 carbons in the alkyl chain were found to have similar interactions with Cu2+ ions. Yet, a slight molecular binding increase was observed when the carbon chain was increased. In addition, lengthening the carbon chain made the extracting stage easier and the stripping stage harder. The binding would result in a lower pH in the extraction step and a lower pH in the stripping step. The insights from this molecular study would help design the extraction circuit using natural-based hydroxyoxime extractants. A successful application of cashew-based cardanol will improve the environmental benefits of the recycling process. With cashew-producing regions in developing countries, the application also improves these regions' social and economic sustainability.

How public health insurance expansion affects healthcare utilizations in middle and low-income households: an observational study from national cross-section surveys in Vietnam.

Public health insurance (PHI) has been implemented with different levels of participation in many countries, from voluntary to mandatory. In Vietnam, a law amendment made PHI compulsory nationwide in 2015 with a tolerance phase allowing people a flexible time to enroll. This study aims to examine mechanisms under which the amendment affected the enrollment, healthcare utilization, and out-of-pocket (OOP) expenditures by middle- and low-income households in this transitioning process.Using the biennial Vietnam Household Living Standard Surveys, the study applied the doubly robust difference-in-differences approach to compare outcomes in the post-amendment period from the 2016 survey with those in the pre-amendment period from the 2014 survey. The approach inheriting advantages from its predecessors, i.e., the difference-in-differences and the augmented inverse-probability weighting methods, can mitigate possible biases in policy evaluations due to the changes within the group and between groups over time in the cross-section observational study.The results showed health insurance expansion with extensive subsidies in premiums and medical coverage for persons other than the full-time employed, young children or elderly members in the family, significantly increased enrollments in the middle- and low-income groups by 9% and 8%, respectively. The number of visits for PHI-eligible services also increased, approximately 0.5 more visit per person in the middle-income and 1 more visit per person in the low-income. The amendment, however, so far did not show any significant effect on reducing OOP payments, neither for the low nor the middle-income groups. To further expand PHI coverage and financial protections, policymakers should focus on improving public health facilities, contracting PHI to more accredited private health providers, and motivating the high-income group's enrollments.

[Standardization of clinical application of mass spectrometry method for measurement of vitamin D in capillary blood of children: a multicenter study].

Objective: To establish the norms and clinical application standards of mass spectrometry method to measure vitamin D in capillary blood. Methods: Following the "Province-City-Hospital" sampling procedure, a cross-sectional sample of 1 655 healthy children under 7 years of age were recruited from 12 provinces, autonomous regions, or municipalities in China from November 2020 to December 2021. Both venous and capillary blood samples from the same individual were collected, for which serum 25(OH)D levels were measured by high-performance liquid chromatography-mass spectrometry (HPLC-MS/MS) method. Pearson correlation analysis and linear regression analysis were used to detect the correlation and determine a correction algorithm. The agreement was analyzed using Bland-Altman plot and Kappa statistic. The sensitivity and specificity were evaluated using receiver operating characteristic (ROC) curve method. Results: Venous and capillary 25(OH)D levels of 1 655 healthy children under 7 years of age were 74.25 (59.50, 92.00) and 68.75 (54.44, 86.25) nmol/L, respectively, showed a significant difference(Z=22.14, P<0.001) as well as a highly significant correlation between venous and capillary 25(OH)D levels(r=0.95, P<0.001). Linear regression analysis was then performed to determine the correction algorithm: lg(corrected capillary 25(OH)D)=0.13+0.95×lg(capillary 25(OH)D)(R2=0.90,P<0.001). The deviation between venous and corrected capillary 25(OH)D levels was (0.50±17.50) nmol/L, a difference value that did not reach statistical significance (P>0.05). The cut-off values of capillary blood 25(OH)D values 30.00, 50.00, 75.00 nmol/L corresponding to venous blood 25(OH)D values were 26.59, 45.56, and 69.84 nmol/L, respectively. Good consistency was observed between venous and corrected capillary 25(OH)D levels in clinical diagnosis (Kappa value 0.68-0.81). Corrected capillary 25(OH)D showed a high clinically predictive value (area under curve 0.97-0.99,sensitivity 0.72-0.92,specificity 0.89-0.99). Conclusion: The standardized capillary HPLC-MS/MS method can be used to detect 25(OH)D levels in children clinically.

VinDr-CXR: An open dataset of chest X-rays with radiologist's annotations.

Most of the existing chest X-ray datasets include labels from a list of findings without specifying their locations on the radiographs. This limits the development of machine learning algorithms for the detection and localization of chest abnormalities. In this work, we describe a dataset of more than 100,000 chest X-ray scans that were retrospectively collected from two major hospitals in Vietnam. Out of this raw data, we release 18,000 images that were manually annotated by a total of 17 experienced radiologists with 22 local labels of rectangles surrounding abnormalities and 6 global labels of suspected diseases. The released dataset is divided into a training set of 15,000 and a test set of 3,000. Each scan in the training set was independently labeled by 3 radiologists, while each scan in the test set was labeled by the consensus of 5 radiologists. We designed and built a labeling platform for DICOM images to facilitate these annotation procedures. All images are made publicly available in DICOM format along with the labels of both the training set and the test set.

Protocol for Measuring Concentrations of Extracellular Vesicles in Human Blood Plasma with Flow Cytometry.

Extracellular vesicles (EVs) are lipid membrane enclosed particles that are released from cells into body fluids, such as blood. EVs offer potential new biomarkers of diseases, because the cellular origin, composition, concentration, and function of EVs change in health and disease. The concentration of EVs from specific cell types in blood can be determined with flow cytometry. A flow cytometer measures fluorescence and light scattering signals from single EVs, but only if these signals are sufficiently bright to be detected. Measured concentrations of EVs are therefore only reproducible and comparable if the detection ranges are known and reported in standard units, such as molecules of equivalent soluble fluorophore (MESF) for fluorescence signals and the diameter in nm for scatter signals. The goal of this protocol is to discuss all steps needed to derive the concentration of cell-type specific EVs within a known diameter range and fluorescence range. More specifically, this protocol describes how to determine the concentration of CD61+ (Integrin beta-3, platelet marker), CD235a+ (Glycophorin A, erythrocyte marker), and CD45+ (leukocyte common antigen) EVs in human blood plasma with an Apogee A60-Micro flow cytometer using scatter-based triggering. The principles behind this protocol could lay a firm basis for the design of a protocol suitable for other flow cytometers and body fluids.

[Analysis of vitamin D status among children under 7 years of age in some regions of China].

Objective: To explore current vitamin D status and influential factors of vitamin D deficiency and insufficiency among children under 7 years of age in 11 provinces, autonomous regions or municipalities of China. Methods: According to the "province-city-hospital" sampling technical route, a total of 1 531 healthy children under 7 years of age were sampled from 11 provinces, autonomous regions or municipalities in China by the cluster random sampling method from November 2020 to November 2021. The demographic information, family conditions, behavior and living habits and feeding behaviors were collected using unified questionnaire. Serum 25-hydroxyvitamin D(25(OH)D) levels were measured by liquid chromatography-tandem mass spectrometry. Serum 25(OH)D<30 nmol/L was considered deficient and 30-50 nmol/L was considered insufficient. With 25(OH)D≤50 nmol/L as the dependent variable, multivariate Logistic regression was applied to analyze the association between vitamin D deficiency and insufficiency and potential influential factors. Results: The prevalence of vitamin D deficiency and insufficiency among children under 7 years of age in 11 provinces, autonomous regions or municipalities of China was 14.0% (215/1 531), 3.8% (25/664) and 21.9% (190/867) in 0-<3 and 3-<7 of age years, respectively. Compared to children aged 0-<3 years, children aged 3-<7 years had a 2.6-fold increased risk of vitamin D deficiency and insufficiency (OR=3.60, 95%CI 1.93-6.72, P<0.001). Frequent sunlight exposure (OR=0.46, 95%CI 0.29-0.73, P=0.001), vitamin D supplementation (sometimes, OR=0.33, 95%CI 0.21-0.51, P<0.001; daily, OR=0.20, 95%CI 0.11-0.36, P<0.001) and infant formula intake(4-7 times per weeks, OR=0.43, 95%CI 0.28-0.68, P<0.001) were protective factors for vitamin D deficiency and insufficiency. Conclusion: Vitamin D deficiency and insufficiency are common among children under 7 years of age in 11 provinces, autonomous regions or municipalities of China, which is affected by age, sunlight exposure, vitamin D supplementation and infant formula intake.

Bullous drug eruption after second dose of mRNA-1273 (Moderna) COVID-19 vaccine: Case report.

BACKGROUND: In December 2020, Moderna released the mRNA-1273 vaccine. The most common side effects are headache, muscle pain, redness, swelling, and tenderness at the injection site. In addition, there have been dermatological adverse events, such as hypersensitivity reactions. Although rare, various bullous eruptions have been described following vaccination. Bullous pemphigoid has been reported to occur most often after receipt of influenza and the diphtheria-tetanus-pertussis vaccine. To the best of our knowledge, there have been no reports of bullous drug eruptions resulting from mRNA vaccines. CASE SUMMARY: A 66-years-old obese Guyanese male presented with a bullous rash following receipt of a commercial COVID-19 mRNA vaccine. He received the first dose uneventfully. However, within 24 h of receiving the second dose, he developed fever, myalgias, and malaise accompanied by a painful blistering rash of his torso, arms, and legs. His fever and myalgias improved after 24 h, but his painful rash did not, and five days after the initial symptoms, he presented to the hospital. There were many violaceous, poorly demarcated patches on his trunk, arms, and thighs on examination, many of which had large flaccid bullae within, and a few areas on his buttocks, posterior shoulder, and scrotum were eroded. The exam was also significant for lower extremity muscle tenderness, stiffness with preserved strength. A skin biopsy showed epidermal necrosis and sparse perivascular dermatitis concerning Stevens-Johnson syndrome or erythema multiforme. However, in the absence of mucous membrane involvement or targetoid lesions, the diagnosis of an extensive bullous fixed drug eruption was made. CONCLUSION: This case illustrates that the bullae eruption occurred as a result of receiving the Moderna vaccination.

Cellular origin and microRNA profiles of circulating extracellular vesicles in different stages of diabetic nephropathy.

BACKGROUND: Diabetic nephropathy (DN) is a major complication of diabetes and the main cause of end-stage renal disease. Extracellular vesicles (EVs) are small cell-derived vesicles that can alter disease progression by microRNA (miRNA) transfer. METHODS: In this study, we aimed to characterize the cellular origin and miRNA content of EVs in plasma samples of type 2 diabetes patients at various stages of DN. Type 2 diabetes patients were classified in three groups: normoalbuminuria, microalbuminuria and macroalbuminuria. The concentration and cellular origin of plasma EVs were measured by flow cytometry. A total of 752 EV miRNAs were profiled in 18 subjects and differentially expressed miRNAs were validated. RESULTS: Diabetic patients with microalbuminuria and/or macroalbuminuria showed elevated concentrations of total EVs and EVs from endothelial cells, platelets, leucocytes and erythrocytes compared with diabetic controls. miR-99a-5p was upregulated in macroalbuminuric patients compared with normoalbuminuric and microalbuminuric patients. Transfection of miR-99a-5p in cultured human podocytes downregulated mammalian target of rapamycin (mTOR) protein expression and downregulated the podocyte injury marker vimentin. CONCLUSIONS: Type 2 diabetes patients with microalbuminuria and macroalbuminuria display differential EV profiles. miR-99a-5p expression is elevated in EVs from macroalbuminuria and mTOR is its validated mRNA target.

Dominant Factors Affecting Regional Inequality of Infant Mortality in Vietnam: A Structural Equation Modelling Analysis.

BACKGROUND: Despite Vietnam's acclaiming achievements of reducing overall infant mortality rate (IMR), the IMR decline does not occur equally in all regions in Vietnam. This study aims to investigate dominant factors that affect the inequality of infant mortality across regions in Vietnam during the period 2005-2015. METHODS: We use nationally representative data to construct a panel data of 6 economic regions in Vietnam from 2005 to 2015. We employ the structural equation modelling (SEM) approach to quantify the causal effect of socio-economic status (SES), accessing to skilled birth attendance (SBA) and other relevant factors on the disparity of IMR across regions. RESULTS: SES, which is measured by 3 indicators - illiteracy rate (IR), poverty rate (PR) and income per capita - is the dominant factor causing regional inequalities of infant mortality, followed by the use of SBA. Among these indicators, the PR is the most important one causing the regional disparity of IMR and accessing to SBA. The total effect of SES on infant mortality disparity is 2.6 times as high as that of accessing skilled healthcare personnel. CONCLUSION: Bridging the regional gap of using skilled health personnel would contribute to improving the infant mortality inequality in Vietnam. This inequality, however, is not significantly improved only with medical interventions but also with broader and more comprehensive socio-economic interventions at both national and regional levels. Our findings confirm that poverty reduction and growth strategies should be the main focus to boost medical interventions and improve IMR all over the country.

Platelet removal by single-step centrifugation.

The study of extracellular vesicles (EVs) in plasma requires removal of cells including platelets. At present, a two-step centrifugation protocol is recommended and commonly used. A simpler protocol that is less operator dependent is likely to improve the quality of plasma samples collected for EV research. The objective of this study is to develop an easy, fast and clinically applicable centrifugation protocol to produce essentially platelet-free plasma with a high yield for EV research. We compared the two-step centrifugation protocol to a single-step protocol at 5,000 g for 20 minutes. The removal of platelets was computationally predicted and experimentally validated. Flow cytometry was used to detect residual platelets and platelet-derived (CD61+) EVs. The single-step protocol at 5,000 g (i) is less laborious and approximately ten minutes faster, (ii) removes platelets as effective as the two-step centrifugation protocol, and (iii) has a ~ 10% higher plasma yield, whereas (iv) the recovery of platelet-derived EVs is comparable. For future research on plasma EVs we recommend the newly developed, easy and fast single-step protocol for preparation of platelet-free plasma for research on plasma biomarkers including EVs.

Rate zonal centrifugation can partially separate platelets from platelet-derived vesicles.

BACKGROUND: Centrifugation is commonly used as a first step to enrich biomarkers from blood. Biomarkers are separated on the basis of density and/or diameter. However, the centrifugation protocol affects the yield and purity of biomarkers, for example, isolation of platelets results in co-isolation with extracellular vesicles (EVs). OBJECTIVE: To assess the ability of rate zonal centrifugation (RZC) to separate platelets from co-isolated EVs. METHODS: Using a linear Optiprep gradient, RZC was able to separate a mixture of beads with different diameters but similar density. Next, RZC was applied to samples containing both platelets and platelet-derived EVs (n = 3). After RZC, all fractions were collected and stained with anti-CD61-Alexa 488 to measure the concentrations of platelets and platelet-derived EVs by flow cytometry. RESULTS: We confirm that RZC separates polystyrene beads with diameters of 140 nm, 380 nm and 1,000 nm. Next, we show that the majority of platelets occur in fractions 8-19, whereas the majority of platelet-derived EVs are detectable in fractions 1-7. Furthermore, each fraction contains a different diameter range of platelets, which suggests that separation is indeed diameter based. CONCLUSION: RZC can partially separate platelets from EVs.

The roles of social economic status and undernutrition in regional disparities of the under-five mortality rate in Vietnam.

OBJECTIVES: From 2005 to 2017, the prevalence of mortality in Vietnamese children under five years old showed large regional disparities. In 2017, mortality in the wealthiest region was 12.6‰, whereas the most disadvantaged region it was three times as high, at 36‰. This study aims to identify factors affecting regional disparities of the under-five mortality rate (U5MR) in Vietnam. METHODS: We applied Structural Equation Modelling to estimate the degree and the pathway through which undernutrition and socio-economic status (SES) contributed to the under-five mortality disparities. RESULTS: SES is estimated as a common latent factor of three socio-economic measures, that is, education, poverty and income. The direct effect of SES on U5MR is at 2.16 through the underweight pathway, which is 5 times higher than the effect of underweight on U5MR. Through the stunting channel, this direct impact is 1.43, nearly twice as high as the impact of the stunting rate. SES also has an indirect effect on U5MR through these undernutrition pathways. In total, we estimate that an increase in SES index will make the U5MR increase by 2.73‰. Among the three indicators of SES, poverty conveys the strongest signal of a considerable change in SES, thus to a subsequent change in U5MR. Among two types of undernutrition, the effect of stunting on U5MR is dominant, more than 3 times as high as that of underweight. CONCLUSION: These findings have important implications for socio-economic and health interventions: those that strongly focus on the reduction of regional poverty and stunting rates would be effective in bridging the regional gap in the U5MR in Vietnam.

OBJECTIFS: De 2005 à 2017, la prévalence de la mortalité chez les enfants vietnamiens de moins de cinq ans a montré de grandes disparités régionales. En 2017, la mortalité dans la région la plus riche était de 12,6 ‰, alors que dans la région la plus défavorisée elle était trois fois plus élevée, à 36 ‰. Cette étude vise à identifier les facteurs affectant les disparités régionales du taux de mortalité des moins de cinq ans (U5MR) au Vietnam. MÉTHODES: Nous avons appliqué la modélisation par équations structurelles pour estimer le degré et la voie par lesquels la sous-nutrition et le statut socioéconomique (SSE) contribuaient aux disparités de mortalité des moins de cinq ans. RÉSULTATS: Le SSE est estimé comme un facteur latent commun à trois mesures socioéconomiques, à savoir l'éducation, la pauvreté et le revenu. L'effet direct du SSE sur l'U5MR est de 2,16 dans la voie de l'insuffisance pondérale, ce qui est 5 fois plus élevé que l'effet de l'insuffisance pondérale sur l'U5MR. A travers la voie du retard de croissance, cet impact direct est de 1,43, soit près de deux fois plus élevé que l'impact du taux de retard de croissance. Le SSE a également un effet indirect sur l'U5MR à travers ces voies de sous-nutrition. Au total, nous estimons qu'une augmentation de l'indice de SSE fera augmenter l'U5MR de 2,73 ‰. Parmi les trois indicateurs du SSE, la pauvreté est le signal le plus fort d'un changement considérable du SSE, donc d'un changement ultérieur de l'U5MR. Parmi deux types de sous-nutrition, l'effet du retard de croissance sur l'U5MR est dominant, plus de 3 fois plus élevé que celui de l'insuffisance pondérale. CONCLUSION: Ces résultats ont des implications importantes pour les interventions socioéconomiques et de santé: celles qui se concentrent fortement sur la réduction de la pauvreté régionale et des taux de retard de croissance seraient efficaces pour combler l'écart régional dans l'U5MR au Vietnam.

[Effects of two dimensional gray-scale blood flow imaging combined with color Doppler flow imaging in guiding arterial puncture and catheterization through wounds in patients with large burns].

Objective: To explore the effects of two dimensional gray-scale blood flow imaging (hereinafter referred to as " B-flow" ) combined with color Doppler flow imaging (CDFI) in guiding arterial puncture and catheterization through wounds in patients with large burns. Methods: Sixty-seven patients with large burns who met the inclusion criteria and hospitalized in the First Hospital of Jilin University from January 2017 to January 2019 were enrolled in the prospectively randomized control study. According to the random number table, CDFI alone group was allocated with 35 patients (23 males and 12 females) and B-flow+ CDFI group with 32 patients (22 males and 10 females), aged 19-60 and 18-58 years, respectively. According to the progress of the disease, arterial puncture and catheterization were performed in the right time. During the operation, CDFI was used alone for guidance in patients of CDFI alone group, while B-flow and CDFI were used together for guidance in patients of B-flow+ CDIF group. Based on the first time of catheterization, the catheterization location, one-time catheterization success rate, post-back stitching re-catheterization success rate, catheterization failure rate, catheterization duration, and incidences of wound sepsis, catheter-related bloodstream infection, and arterial thrombosis within post catheterization day (PCD) 3 of patients in the two groups were recorded. Data were statistically analyzed with the independent-sample t test, chi-square test or Fisher's exact probability test. Results: (1) All the patients underwent catheterization through wounds, and there was no statistically significant difference in catheterization location of patients between the two groups (χ(2)=0.574, P>0.05). The one-time catheterization success rate of patients in B-flow+ CDFI group was 81.25% (26/32), which was obviously higher than 51.43% (18/35) in CDFI alone group (χ(2)=6.594, P<0.05). The catheterization failure rate of patients in B-flow+ CDFI group was 3.12% (1/32), which was obviously lower than 20.00% (7/35) in CDFI alone group (P<0.05). The post-back stitching re-catheterization success rate of patients was similar between the two groups (χ(2)=1.029, P>0.05). (3) The catheterization duration of patients was (15.7±1.1) min in B-flow+ CDFI group, which was obviously shorter than (17.1±2.2) min in CDFI alone group (t=11.316, P<0.01). (4) Within PCD 3, the incidences of wound sepsis and catheter-related bloodstream infection of patients in CDFI alone group were 2.86% (1/35) and 0, close to 0 and 3.12% (1/32) in B-flow+ CDFI group (P>0.05); the incidence of arterial thrombosis of patients in B-flow+ CDFI group was 0, which was obviously lower than 20.00% (7/35) in CDFI alone group (P<0.05). Conclusions: Compared with CDFI alone, B-flow combined with CDFI can improve the success rate of arterial puncture and catheterization through wounds in large area burn patients, shorten the catheterization duration, and effectively reduce the incidence of arterial thrombosis after catheterization, with a good clinical application value.

Surface Potential of the Air/Water Interface.

The surface charge/surface potential of the air/water interface plays a key role in many natural and industrial processes. Since the first decade of the 20th century, there are many theoretical proposals to describe the surface charge in the presence of different moieties. However, a complete and consistent description of the interfacial layer remains elusive. More recently, the theoretical frameworks and experimental data get complementary support from the simulation at a molecular level. This paper reviews the recent developments from the theoretical, experimental and simulation aspects. The combined results indicated that the interaction between hydration shells of adsorbed ions and the H-bonds network of surface water plays a critical role in the ionic adsorption. The factor should be incorporated into the conventional theories to correctly predict the ion distribution near the air/water surface.

Label-free identification and chemical characterisation of single extracellular vesicles and lipoproteins by synchronous Rayleigh and Raman scattering.

Extracellular vesicles (EVs) present in blood originate from cells of different origins such as red blood cells (RBCs), platelets and leukocytes. In patients with cancer, a small portion of EVs originate from tumour cells and their load is associated with poor clinical outcome. Identification of these tumour-derived extracellular vesicles (tdEVs) is difficult as they are outnumbered by EVs of different tissue of origin as well a large number of lipoproteins (LPs) that are in the same size range. In order to detect tdEVs from the abundant presence of other particles, single-particle techniques are necessary. Here, synchronous Rayleigh and Raman scattering is used for that purpose. This combination of light scattering techniques identifies optically trapped single particles based on Rayleigh scattering and distinguishes differences in chemical composition of particle populations based on Raman scattering. Here, we show that tdEVs can be distinguished from RBC EVs and LPs in a label-free manner and directly in suspension.