A quantitative description of specific ion effects is an essential and focused topic in colloidal and biological science. In this work, the dynamic light scattering technique was employed to study the aggregation kinetics of colloidal particles in the various alkali ion solutions with a wide range of concentrations. It indicated that the activation energies could be used to quantitatively characterize specific ion effects, which was supported by the results of effective hydrodynamic diameters, aggregation rates and critical coagulation concentrations. At a given concentration of 25 mmol L(-1), the activation energies for Li(+) are 1.2, 5.7, 28, and 126 times as much for Na(+), K(+), Rb(+), and Cs(+), respectively. Most importantly, the activation energy differences between two alkali cation species increase sharply with decrease of electrolyte concentrations, implying the more pronounced specific ion effects at lower concentrations. The dominant role of electrolyte cations during the aggregation of negatively charged colloidal particles was confirmed by alternative anions. Among the various theories, only the polarization effect can give a rational interpretation of the above specific ion effects, and this is substantially supported by the presence of strong electric fields from montmorillonite surfaces and its association mainly with electrolyte cations and montmorillonite particles. The classical induction theory, although with inclusion of electric field, requires significant corrections because it predicts an opposite trend to the experimentally observed specific ion effects.

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This study was designed to identify predictors of lower versus higher willingness to use pre-exposure prophylaxis (PrEP) to reduce HIV among men who have sex with men (MSM) in China. Participants were 570 MSM who completed self-report measures of willingness to use HIV PrEP, beliefs about HIV, psychosocial factors, sexual experiences and sociodemographic characteristics. Results of a hierarchical binary logistic regression analysis indicated that membership in a higher willingness group was predicted by previous consultation about HIV, more reported barriers to using condoms, and elevations in depressive symptoms. Independent of these factors, higher willingness to use HIV PrEP was predicted by beliefs that the intervention was low in stigma and high in potential benefits. In sum, the study highlighted the utility of broad-based assessment of demographic, behavioral, personality, and cognitive factors in identifying Chinese MSM who express willingness to use a promising biologically-based intervention to lower HIV risk.

EORA and YORA patients had different demographic characteristics. Although they had similar disease activities, EORA patients received less intensive treatment. EORA patients had a higher number of RA-related co-morbidities and poorer physical functioning but they coped better emotionally and mentally.

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