Global and regional estimates of the morbidity due to type I diabetes among children aged 0-4 years:a systematic review and analysis

Background: Epidemiology of type 1 diabetes mellitus (T1DM) among children aged 0-4 years globally is not well understood. We aim to assess the incidence of T1DM in low- and middle-income countries (LMIC) by conducting a systematic review of previous reports. We also aim to address possible contribution to child mortality and to identify any temporal trends. Methods: A systematic review was performed using a carefully designed search strategy to explore MEDLINE, EMBASE and Global Health databases. Data was extracted from all studies that satisfied the inclusion criteria -a total of 83 records extracted from 26 830 sources that were analysed. We used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) process to assess quality of evidence and applied meta-analysis approaches to assess global and regional incidence and time trends. Results: The overall pooled incidence of T1DM in children aged 0-4 years globally is 11.2 (95% CI = 10.0-12.3) per 100 000 child years. The regional incidence were the highest for European Region A (EUR A) at 15.5 (95% CI = 13.5-17.5) per 100 000 child years. EUR C had the incidence of 10.0 (95% CI = 6.5-13.6) and EUR B 5.8 (95% CI = 4.7-7.0), Region of the Americas A (AMR A) 11.4 (95% CI = 7.8-14.9), AMR B of 2.5 (95% CI = 0.2-4.8), Eastern Mediterranean Region (EMR B) 7.1 (95% CI = 4.2-10.0) and Western Pacific Region (WPR A) 7.0 (95% CI = 2.9-11.0) per 100 000 child years, while other regions had very low rates or no data. When data points were categorised in the study periods and re-analysed, an increasing trend of the T1DM incidence was observed, with the incidence of 20.9 (95% CI = 7.8-34.1) per 100 000 child years in the years 2010-2015, preceded by 13.2 (95% CI = 11.0-15.5) in 2000-2009 study period, 10.0 (95% CI = 8.4-11.7) in 1990-1999 and 8.3 (95% CI = 5.1-11.6) in 1980-1989, respectively. Although the data are scarce, and variation and uncertainty are large, we estimated that the number of new cases of T1DM among children aged 0-4 years in the world each year is between 100 000 and 150 000. Conclusions: The identified large variation in incidence estimates for different parts of the world, along with scarcity of information and the identified strong temporal increase in T1DM incidence suggest a clear need for further research into this subject

13C NMR study of the mixture MBBA/EBBA/decane: The influence of decane on the molecular ordering in the nematic phase

Influence of various amounts of decane dissolved in the eutectic nematic mixture in methoxybenzylidenebutylaniline and ethoxybenzylidenebutylaniline (MBBA/EBBA) on the ordering and structure of mesomorphic molecules has been determined employing high-resolution proton enhanced 13C NMR spectroscopy. The obtained results are compared with temperature behaviour of the ordering and structure of EBBA studied by means of the same technique. Slight differences in the ordering of the phenyl parts of molecules in the dependence on temperature and on decane concentration have been observed. This contrasts with great differences observed in the behaviour of the butyl parts of mesogenic molecules. Two possible explanation of the behaviour of butyl chain atoms in the dependence on decane concentration are presented. According to one approach, conformational order parameters of the first butyl carbons increase with the increasing decane concentration. Another possibility is that decane increases the correlation between the whole molecule rotation and the internal rotation around the first butyl bond.</jats:p

Structure and 13C MAR NMR spectra of various forms of isomeric methyl xylobiosides

All so far known crystalline forms of all positional isomers of methyl β-D-xylopyranosyl-β-D-xylopyranoside were prepared and their high resolution 13C NMR spectra measured by the magic angle rotation (MAR) method using cross-polarization (CP). According to these spectra only two modifications of methyl 4-O-(β-D-xylopyranosyl)-β-D-xylopyranoside (modifications IVβ and IVγ) contain more than one molecule in the crystal elementary cell; in all other studied disaccharide samples all molecules are equivalent. The majority of carbon-13 chemical shifts could be assigned, at least partially, by a comparison with solution spectra. Some of the glycosidic carbons in the units with methyl aglycone (ring A) exhibit surprisingly large paramagnetic shifts with respect to the solution chemical shifts. Apparently, molecular structures at these sites in solids differ most from the average structures the molecules assume in the liquid phase. Assuming that solid state chemical shifts are affected also by similar factors as the shifts in solution, the methyl aglycone carbon chemical shifts indicate that the frozen conformation of the ring A in the solid is closer either to 1C4 conformation (modifications IIIα and II) or to 4C1 conformation (modification IVα) than are the respective equilibrium conformations in solution. Thermal analysis has proven, however, that the xylobioside forms with two nonequivalent molecules in the cell similarly as some other forms are indeed hydrates. Thus is shown that all the methyl xylobiosides are monomorphous, all the polymorphs are not true polymorphs but forms hydrated to a different extent.</jats:p