Langevin behavior of the dielectric decrement in ionic liquid water mixtures

We present large scale polarizable simulations of mixtures of the ionic liquids 1-ethyl-3-methylimidazolium trifluoromethanesulfonate and 1-ethyl-3-methylimidazolium dicyanamide with water, where the dielectric spectra, the ion hydration and the conductivity were evaluated. The dielectric decrement, the depression of the dielectric constant of water upon addition of ions, is found to follow a universal functional of Langevin type. Only three physical properties need to be known to describe the complete range of possible concentrations, namely the dielectric constant of pure water, of pure ionic liquid and the linear slope of the dielectric decrement at low ionic liquid concentrations. Both the generalized dielectric constant, as well as the water contribution to the dielectric permittivity follow the functional dependence. We furthermore find that a scaling of van der Waals parameters upon addition of polarizable forces to the force field is necessary to correctly describe the frequency dependent dielectric conductivity and its contribution to the dielectric spectrum, as well as the static electric conductivity, which is also treated in the framework of a pseudolattice theoryThis work was funded by the Austrian Science Fund FWF in the context of Project No. P23494 and by the Cost Action CM 1206: “Exchange on ionic liquids”. Funding from Spanish Ministry of Economy and Competitiveness (Projects MAT2014-57943-C3-1-P and MAT2017-89239-C2-1-P) is gratefully acknowledged. Moreover, this work was funded by the Xunta de Galicia (AGRUP2015/11 and GRC ED431C 2016/001). E. H. is recipient of a DOC Fellowship of the Austrian Academy of Sciences at the Institute of Computational Biological ChemistryS

Transfusion / Glycated hemoglobin concentrations of packed red blood cells minimally increase during storage under standard blood banking conditions

BACKGROUND Few and inconsistent data exist describing the effect of storage duration on glycated hemoglobin (HbA1c) concentrations of red blood cells (RBCs), impeding interpretation of HbA1c values in transfused diabetic patients. Hence the aim of this study was to evaluate to what extent HbA1c concentrations of RBCs change during the maximum allowed storage period of 42 days. STUDY DESIGN AND METHODS Blood was drawn from 16 volunteers, leukofiltered, and stored under standard blood banking conditions. HbA1c concentrations of RBCs were measured on Days 1 and 42 of storage using three different validated devices (ionexchange highperformance liquid chromatography Method A1 and A2, turbidimetric immunoassay Method B). RESULTS Mean HbA1c concentrations of RBCs on Day 1 were 5.3 0.3% (Method A1), 5.4 0.4% (Method A2), and 5.1 0.4% (Method B). HbA1c concentrations increased to 5.6 0.3% (A1, p < 0.0001), 5.7 0.3% (A2, p = 0.004), and 5.5 0.4% (B, p < 0.0001) on Day 42, respectively, corresponding to a 1.06fold increase across all methods. Glucose concentrations in the storage solution of RBCs decreased from 495 27 to 225 55 mg/dL (p < 0.0001), confirming that stored RBCs were metabolically active. CONCLUSION These results suggest a significant, albeit minor, and most likely clinically insignificant increase in HbA1c concentrations during storage of RBCs for 42 days.(VLID)341760

Kidney biopsy in patients with glomerulonephritis: is the earlier the better?

<p>Abstract</p> <p>Background</p> <p>Interventional diagnostic procedures are established for several diseases in medicine. Despite the KDOQI guideline recommendation for histological diagnosis of kidney disease to enable risk stratification, its optimal time point has not been evaluated. We have therefore analyzed whether histological diagnosis of glomerulonephritis (GN) at an early stage of chronic kidney disease (CKD) is associated with different outcome compared to diagnosis at a more advanced stage.</p> <p>Methods</p> <p>A cohort of 424 consecutive patients with histological diagnosis of GN were included in a retrospective data analysis. Kidney function was assessed by glomerular filtration rate (GFR) estimation at the time point of kidney biopsy and after consecutive immunosuppressive therapy. Censored events were death, initiation of dialysis or kidney transplantation, or progression of disease, defined as deterioration of CKD stage ≥1 from kidney biopsy to last available kidney function measurement.</p> <p>Results</p> <p>Occurrence of death, dialysis/transplantation or progression of disease were associated with GFR and CKD stage at the time of kidney biopsy (<it>p</it> < 0.001 for all). Patients with CKD stage 1 and 2 at kidney biopsy had fewer endpoints compared to patients with a GFR of <60 ml/min (<it>p</it> < 0.001).</p> <p>Conclusion</p> <p>Kidney function at the time point of histological GN diagnosis is associated with clinical outcome, likely due to early initiation of specific drug treatment. This suggests that selection of therapy yields greatest benefit before renal function is impaired in GN.</p