Interfacial structuring of non-halogenated imidazolium ionic liquids at charged surfaces : effect of alkyl chain length

Control of the interfacial structures of ionic liquids (ILs) at charged interfaces is important to many of their applications, including in energy storage solutions, sensors and advanced lubrication technologies utilising electric fields. In the case of the latter, there is an increasing demand for the study of non-halogenated ILs, as many fluorinated anions have been found to produce corrosive and toxic halides under tribological conditions. Here, the interfacial structuring of a series of four imidazolium ILs ([C(n)C(1)Im]) of varying alkyl chain lengths (n = 5, 6, 7, 10), with a non-halogenated borate-based anion ([BOB]), have been studied at charged interfaces using sum frequency generation (SFG) spectroscopy and neutron reflectivity (NR). For all alkyl chain lengths, the SFG spectra show that the cation imidazolium ring responds to the surface charge by modifying its orientation with respect to the surface normal. In addition, the combination of SFG spectra with electrochemical NR measurements reveals that the longest alkyl chain length (n = 10) forms a bilayer structure at all charged interfaces, independent of the ring orientation. These results demonstrate the tunability of IL interfacial layers through the use of surface charge, as well as effect of the cation alkyl chain length, and provide valuable insight into the charge compensation mechanisms of ILs

Childhood diabetes: parents' experience of home management and the first year following diagnosis

Aims To explore parents’ experience of having a child diagnosed with Type 1 diabetes, managed at home, and their first year following diagnosis. Methods A qualitative, longitudinal study based on 40 in-depth interviews with parents of 20 children with newly diagnosed Type 1 diabetes managed at home from diagnosis in South Wales. Results Many parents were alarmed by the speed of diagnosis following the gradual progress of their child's symptoms. The provision of timely, adequate information was important to all parents. Although five parents had initial concerns about going home, all parents were subsequently pleased their children had not been hospitalized. Home management enabled parents to integrate diabetes management into the family's normal lifestyle from diagnosis. Professional support, particularly accessible telephone advice, was valued by and reassured parents. Parents experienced a loss of spontaneity, a continuing fear of hypoglycaemia and did not want their child to feel different to other children. Acutely aware of the seriousness of diabetes, they did their utmost to achieve optimal glycaemic control but felt that diabetes could not ‘dominate’ if they were to lead a ‘normal’ life. Conclusions The experience of parents in this study suggests that parents of children with newly diagnosed diabetes are able to cope successfully when given the opportunity to start treatment at home. Therefore, if children with diabetes are clinically well at diagnosis, this study supports home management as a system of care from the parents’ point of view. These findings are relevant to clinicians, policy makers and health service managers involved in planning and providing paediatric diabetes car

Novel mutations of the growth hormone 1 (GH1) gene disclosed by modulation of the clinical selection criteria for individuals with short stature

Subtle mutations in the growth hormone 1 (GH1) gene have been regarded as a comparatively rare cause of short stature. Such lesions were sought in a group of 41 individuals selected for short stature, reduced height velocity, and bone age delay; a group of 11 individuals with short stature and idiopathic growth hormone deficiency (IGHD); and a group of 154 controls. Heterozygous mutations were identified in all three groups but disproportionately in the individuals with short stature, both with (odds ratio 25.2; 95% CI, 5.1–132.2) and without (odds ratio 3.6; 95% CI, 1.0–12.9) IGHD. Twenty-four novel GH1 gene lesions were found. Thirteen novel missense mutations were characterized by assaying the signal transduction activity of in vitro expressed variants; six (T27I, K41R, N47D, S71F, S108R, and T175A) exhibited a reduced ability to activate the JAK/STAT pathway. Molecular modeling suggested that both K41R and T175A might compromise GH receptor binding. Seven GH variants (R16C, K41R, S71F, E74K, Q91L, S108C, and a functional polymorphism, V110I) manifested reduced secretion in rat pituitary cells after allowance had been made for the level of expression attributable to the associated GH1 proximal promoter haplotype. A further leader peptide variant (L-11P) was not secreted. Eleven novel mutations in the GH1 gene promoter were assessed by reporter gene assay but only two, including a GH2 gene-templated gene conversion, were found to be associated with a significantly reduced level of expression. Finally, a novel intron 2 acceptor splice-site mutation, detected in a family with autosomal dominant type II IGHD, was shown to lead to the skipping of exon 3 from the GH1 transcript. A total of 15 novel GH1 gene mutations were thus considered to be of probable phenotypic significance. Such lesions are more prevalent than previously recognized and although most may be insufficient on their own to account for the observed clinical phenotype, they are nevertheless likely to play a contributory role in the etiology of short stature