Determinants of health-related quality of life in children and adolescents living with type 1 diabetes mellitus during the COVID-19 pandemic.

AIM: To identify the determinants of self-reported health-related quality of life in children and adolescents with type 1 diabetes mellitus during the coronavirus pandemic. DESIGN: A cross-sectional study. METHODS: The study sample included 182 children and adolescents who had been diagnosed with type 1 diabetes mellitus at least 3 months prior. Data collection instruments included sociodemographic and glycaemic control protocol adherence questionnaires, documentation sheet for recording clinical data, and Serbian versions of the EuroQol-5D-Y and KidScreen27 questionnaires, which were used to assess health-related quality of life. RESULTS: Glycaemic control adherence, presence of comorbidities, level of metabolic control, and type of insulin therapy were identified as key determinants of self-reported health-related quality of life. PATIENT OR PUBLIC CONTRIBUTION: No patient or public contributions.

Microsecond time-scale kinetics of transient biochemical reactions.

To afford mechanistic studies in enzyme kinetics and protein folding in the microsecond time domain we have developed a continuous-flow microsecond time-scale mixing instrument with an unprecedented dead-time of 3.8 ± 0.3 µs. The instrument employs a micro-mixer with a mixing time of 2.7 µs integrated with a 30 mm long flow-cell of 109 µm optical path length constructed from two parallel sheets of silver foil; it produces ultraviolet-visible spectra that are linear in absorbance up to 3.5 with a spectral resolution of 0.4 nm. Each spectrum corresponds to a different reaction time determined by the distance from the mixer outlet, and by the fluid flow rate. The reaction progress is monitored in steps of 0.35 µs for a total duration of ~600 µs. As a proof of principle the instrument was used to study spontaneous protein refolding of pH-denatured cytochrome c. Three folding intermediates were determined: after a novel, extremely rapid initial phase with τ = 4.7 µs, presumably reflecting histidine re-binding to the iron, refolding proceeds with time constants of 83 µs and 345 µs to a coordinatively saturated low-spin iron form in quasi steady state. The time-resolution specifications of our spectrometer for the first time open up the general possibility for comparison of real data and molecular dynamics calculations of biomacromolecules on overlapping time scales.

Design of turbulent tangential micro-mixers that mix liquids on the nanosecond time scale.

Unravelling (bio)chemical reaction mechanisms and macromolecular folding pathways on the (sub)microsecond time scale is limited by the time resolution of kinetic instruments for mixing reactants and observation of the progress of the reaction. To improve the mixing time resolution, turbulent four- and two-jet tangential micro-mixers were designed and characterized for their mixing and (unwanted) premixing performances employing acid-base reactions monitored by a pH-sensitive fluorescent dye. The mixing performances of the micro-mixers were determined after the mixing chamber in a free-flowing jet. The premixing behavior in the vortex chamber was assessed in an optically transparent glass-silicon replica of a previously well-characterized stainless-steel four-jet tangential micro-mixer. At the highest flow rates, complete mixing was achieved in 160ns with only approximately 9% premixing of the reactants. The mixing time of 160ns is at least 50 times shorter than estimated for other fast mixing devices. Key aspects to the design of ultrafast turbulent micro-mixers are discussed. The integration of these micro-mixers with an optical flow cell would enable the study of the very onset of chemical reactions in general and of enzyme catalytic reactions in particular.