Interaction of nanodiamonds with water: Impact of surface chemistry on hydrophilicity, aggregation and electrical properties

In recent decades, nanodiamonds (NDs) have earned increasing interest in a wide variety of research fields, thanks to their excellent mechanical, chemical, and optical properties, together with the possibility of easily tuning their surface chemistry for the desired purpose. According to the application context, it is essential to acquire an extensive understanding of their interaction with water in terms of hydrophilicity, environmental adsorption, stability in solution, and impact on electrical properties. In this paper, we report on a systematic study of the effects of reducing and oxidizing thermal processes on ND surface water adsorption. Both detonation and milled NDs were analyzed by combining different techniques. Temperature-dependent infrared spectroscopy was employed to study ND surface chemistry and water adsorption, while dynamic light scattering allowed the evaluation of their behavior in solution. The influence of water adsorption on their electrical properties was also investigated and correlated with structural and optical information obtained via Raman/photoluminescence spectroscopy. In general, higher oxygen-containing surfaces exhibited higher hydrophilicity, better stability in solution, and higher electrical conduction, although for the latter the surface graphitic contribution was also crucial. Our results provide in-depth information on the hydrophilicity of NDs in relation to their surface chemical and physical properties, by also evaluating the impacts on their aggregation and electrical conductance

Evaluating digital diabetic retinopathy screening in people aged 90 years and over

To evaluate the effectiveness of digital diabetic retinopathy screening in patients aged 90 years and over.MethodsThis is a retrospective analysis of 200 randomly selected patients eligible for diabetic retinopathy screening aged 90 years and over within the Birmingham, Solihull, and Black Country Screening Programme.ResultsOne hundred and seventy-nine (90%) patients attended screening at least once. 133 (74%) annual screening after their first screen, of whom 59% had no detectable diabetic retinopathy; 38 (21%) were referred for ophthalmology clinical assessment-36 for nondiabetic retinopathy reasons and two for diabetic maculopathy. Cataract accounted for 50% of all referrals for ophthalmology clinical assessment. Of the 133 patients placed on annual screening, 93 (70%) were screened at least once more. In terms of level of diabetic retinopathy, assessability or other ocular pathologies, 8 improved, 51 remained stable, and 31 deteriorated. Of the latter, 19 patients were referred for ophthalmology clinical assessment; none of these for diabetic retinopathy.ConclusionsScreening provides opportunistic identification of important nondiabetic retinopathy eye conditions. However, in view of the low identification rate of sight-threatening diabetic retinopathy in patients aged 90 years and over, and the current mission statement of the NHS Diabetic Eye Screening Programme, systematic annual diabetic retinopathy screening may not be justified in this age group of patients, but rather be performed in optometric practice

Ursodeoxycholic acid therapy in primary biliary cirrhosis

A review is made of the literature regarding the present status of ursodeoxycholic acid in the treatment of primary biliary cirrhosis, focusing on the difficulties encountered in establishing the efficacy of this and any other therapy in the management of the disease. It is concluded that further studies or, at least, an updated meta-analysis including the final data emerging from the multicentre, long-term, randomised, double-blind, controlled trials currently under way are needed to establish the clinical importance of ursodeoxycholic acid as a therapeutic agent in primary biliary cirrhosis