Neutral Heteroleptic Lanthanide Complexes for Unravelling Host-Guest Assemblies in Organic Solvents: The Law of Mass Action Revisited.

The binding of lanthanide containers [Ln(ß-diketonate)3dig] [dig = 1-methoxy-2-(2-methoxyethoxy)ethane] to aromatic tridentate N-donor ligands (L) in dichloromethane produces neutral nine-coordinate heteroleptic [LLn(ß-diketonate)3] complexes, the equilibrium reaction quotients of which vary with the total concentrations of the reacting partners. This problematic drift prevents the determination of both reliable thermodynamic stability constants and intrinsic host-guest affinities. The classical solution theory assigns this behavior to changes in the activity coefficients of the various partners in nonideal solutions, and a phenomenological approach attempts to quantitatively attribute this effect to some partition of the solvent molecules between bulk-innocent and contact-noninnocent contributors to the chemical potential. This assumption eventually predicts an empirical linear dependence of the equilibrium reaction quotient on the concentration of the formed [LLn(ß-diketonate)3] complexes, a trend experimentally supported in this contribution for various ligands L differing in lipophilicity and nuclearity and for lanthanide containers grafted with diverse ß-diketonate coligands. Even if the origin of the latter linear dependence is still the subject of debate, this work demonstrates that this approach can be exploited by experimentalists for extracting reliable thermodynamic constants suitable for analyzing and comparing host-guest affinities in organic solvents.

Strategic implications of changing rule of halves in hypertension: A cross-sectional observational study.

CONTEXT: The burden of non-communicable diseases will sooner overwhelm the health system of the country and could curtail future economic development. Hypertension causes highest cardiovascular morbidities. To attain target Blood Pressure (BP), different strategies are required, which are area specific. The validity of rule of halves of hypertension in various settings needs to be studied for developing strategies for that particular geographical area. To utilize the resources in more efficient way, strategies need to differ in rural-urban and underserved- well-served areas. AIMS: The present study aims at exploring whether the rule of halves holds good in the city of Mumbai as the findings of such research may have implications on strategies to control hypertension in communities. Hence, the objectives of this study are to ascertain the proportion of persons with hypertension with respect to the status of diagnosis, treatment, adequate treatment, and validate it with existing rule of halves. SETTING AND DESIGN: Study was conducted in the urban field practice area of a teaching hospital and medical college of Mumbai that comprises 42 chawl (housing structures); study design- cross-sectional observational study. MATERIALS AND METHODS: This observational cross-sectional study was conducted over a period of 18 months in the field practice area of a teaching hospital and medical college of Mumbai with a total population of 43,069. Sample size was 667. After ethical clearance, participants were interviewed using pretested semi-structured interview schedule that included socio-demographic factors, risk factor evaluation, clinical examination, and anthropometry. Subjects with diagnosed hypertension were questioned thoroughly about hypertension adherence. STATISTICAL ANALYSIS: Descriptive statistics was applied on quantitative data. RESULTS: A total of 667 people from five chawls of age more than 35 years were included into the study. The mean age of study subjects was 50.84 ± 11.47 years. Out of total 667 respondents, 20.3% respondents were normotensive, 50.3% respondents were pre-hypertensive, 25.3% respondents were in stage 1 hypertension, and 4% respondents were in stage 2 hypertension. In contrary to the classical rule of halves, the present study shows only 31% of the diagnosed hypertensives are adequately treated. CONCLUSIONS: The strategies in the national programs are from the traditional understanding of rule of halves and emphasize increasing awareness and treatment. Family physician should actively involve in regular screening, treatment, and adherence of hypertension treatment. As a part of primary care, community participation is required for effectively achieving the target BP goal of the population.

Spectrally and Spatially Multiplexed Serological Array-in-Well Assay Utilizing Two-Color Upconversion Luminescence Imaging.

We demonstrate a simple dual-mode multiplexed array-in-well immunoassay for simultaneous classification and detection of serum IgG and IgM antibodies against influenza A and human adenoviruses based on the color and position of the upconversion luminescence on the array. Biotinylated influenza A/H1N1 and A/H5N1 as well as adenovirus serotype 2 and 5 hexon antigens along with positive and negative controls were printed in an array format onto the bottom of streptavidin-coated microtiter wells. The anti-influenza A and antiadenovirus antibodies present in the sample were captured to the array and detected with antihuman antibody-coated upconverting nanophosphors (UCNPs). The green emitting UCNPs (NaYF4:Yb(3+),Er(3+)) coated with antihuman IgG and blue emitting UCNPs (NaYF4:Yb(3+),Tm(3+)) coated with antihuman IgM were used to detect human IgG and IgM antibodies, respectively. The emission of the bound UCNPs was imaged free of autofluorescence with anti-Stokes photoluminescence microwell imager. No spectral cross-talk was observed between green and blue emitting UCNPs. Also the cross-reactivities between UCNP-conjugates and immobilized human IgG and IgM antibodies were negligible. Position of the signal on the array defined the antigen specificity and the antibody class was defined by the color of the upconversion luminescence. This technology could be used for differentiation between acute infection from past infection and immunity. Additionally, the class of the antibody response can be used for the differentiation between primary and secondary infections, hence, facilitating epidemiological seroprevalence studies.

Versatile synthetic strategy for coating upconverting nanoparticles with polymer shells through localized photopolymerization by using the particles as internal light sources.

We present a straightforward and generic strategy for coating upconverting nanoparticles (UCPs) with polymer shells for their protection, functionalization, conjugation, and for biocompatibility. UCPs are attracting much attention for their potential use as fluorescent labels in biological applications. However, they are hydrophobic and non-compatible with aqueous media; thus prior surface modification is essential. Our method uses the internal UV or visible light emitted from UCPs upon photoexcitation with near-infrared radiation, to locally photopolymerize a thin polymer shell around the UCPs. In this way, a large variety of monomers with different chemical functionalities can be incorporated. If required, a second layer can be added on top of the first. Our method can provide a large spectrum of surface functional groups rapidly and in one pot, hence offering a platform for the preparation of libraries of functional polymer-encapsulated UCPs for applications in bioassays, biosensing, optical imaging, and theranostics.