Lanthanide-doped luminescent ionogels

Ionogels are solid oxide host networks con. ning at a meso-scale ionic liquids, and retaining their liquid nature. Ionogels were obtained by dissolving lanthanide(III) complexes in the ionic liquid 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide, [C(6)mim][Tf2N], followed by confinement of the lanthanide-doped ionic liquid mixtures in the pores of a nano-porous silica network. [C(6)mim][Ln(tta)(4)], where tta is 2-thenoyltrifluoroacetonate and Ln = Nd, Sm, Eu, Ho, Er, Yb, and [choline](3)[Tb(dpa)(3)], where dpa = pyridine-2,6-dicarboxylate (dipicolinate), were chosen as the lanthanide complexes. The ionogels are luminescent, ion-conductive inorganic-organic hybrid materials. Depending on the lanthanide(III) ion, emission in the visible or the near-infrared regions of the electromagnetic spectrum was observed. The work presented herein highlights that the confinement did not disturb the first coordination sphere of the lanthanide ions and also showed the excellent luminescence performance of the lanthanide tetrakis beta-diketonate complexes. The crystal structures of the complexes [C(6)mim][Yb(tta)(4)] and [choline](3)[Tb(dpa)(3)] are reported.

Luminescence of LaF3:Ln(3+) Nanocrystal Dispersions in Ionic Liquids

Ionic liquids were used as solvents for dispersing luminescent lanthanide-doped LaF3:Ln(3+) nanocrystals (Ln(3+) = Eu3+ and Nd3+). To increase the solubility of the inorganic nanoparticles in the ionic liquids, the nanocrystals were prepared with different stabilizing ligands, i.e., citrate, N,N,N-trimethylglycine (betaine), and lauryldimethylglycine (lauryl betaine). LaF3:5%Ln(3+) :betaine could successfully be dispersed in 1-butyl-1-methylpyrrolidinium bis(tiifluoromethylsulfonyl)imide [C(4)mpyr][Tf2N], 1-butyl-1-methylpyrrolidinium trifluoromethanesulfonate [C(4)mpyr][TfO], and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [C(4)mim][Tf2N] but only in limited amounts. Red photoluminescence was observed for the europium(III)-containing nanoparticles and near-infrared luminescence for the neodymium(III)-containing systems.

Visible-light-sensitized near-infrared luminescence from rare-earth complexes of the 9-hydroxyphenalen-1-one ligand

The unique absorption properties of the 9-hydroxyphenalen-1-one (HPHN) ligand have been exploited to obtain visible-light-sensitizable rare-earth complexes in 1: 3 and 1: 4 metal-to-ligand ratios. In both stoichiometries (1:3,tris,Ln(PHN)3;1:4, tetrakis, A[ Ln( PHN)(4)], with Ln being a trivalent rare-earth ion and A being a monovalent cation), the complexes of Nd(III),Er( III), and Yb(III) show typical near-infrared luminescence upon excitation with visible light with wavelengths up to 475 nm. The X-ray crystal structures of the tris complexes show solvent coordination to the central rare-earth ion, whereas in the tetrakis complexes, the four PHN-ligands form a protective shield around the central ion, preventing small solvent molecules from coordinating to the rare-earth ion, at least in the solid state.

Study of the luminescence of tris(2-thenoyltrifluoroacetonato)lanthanide(III) complexes covalently linked to 1,10-phenanthroline-functionalized hybrid sol-gel glasses

The solubility and uniform distribution of lanthanide complexes in sol-get glasses can be improved by covalently linking the complexes to the sol-gel matrix. In this study, several lanthanide beta-diketonate complexes (Ln = Nd, Sm, Eu, Tb, Er, Yb) were immobilized on a 1,10-phenanthroline functionalized sol-gel glass. For the europium(Ill) complex, a sol-gel material of diethoxydimethylsilane (DEDMS) with polymer-like properties was derived. For the other lanthanide complexes, the sol-gel glass was prepared by using a matrix of tetramethoxysilane (TMOS) and DEDMS. Both systems were prepared under neutral reaction conditions. High-resolution emission and excitation spectra were recorded. The luminescence lifetimes were measured. (c) 2004 Elsevier B.V. All rights reserved.

Visible light sensitisation of europium(III) luminescence in a 9-hydroxyphenal-1-one complex

The 9-hydroxyphenal-1-one ligand forms stable 3 : 1 complexes with trivalent lanthanides, in which it acts as an antenna suitable for the visible light excitation ( up to 475 nm) of the trivalent europium ion.

Intense near-infrared luminescence of anhydrous lanthanide(III) iodides in an imidazolium ionic liquid

Anhydrous neodymium(III) iodide and erbium(Ill) iodide were dissolved in carefully dried batches of the ionic liquid 1-dodecyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [C(12)mim][Tf2N]. Provided that the ionic liquid had a low water content, intense near-infrared emission could be observed for both the neodymium(III) ion and for the erbium(III) ion. Luminescence lifetimes have been measured, and the quantum yield of the neodymium(III) sample has been measured. Exposure of the hygroscopic samples to atmospheric moisture conditions caused a rapid decrease of the luminescence intensities. (C) 2004 Elsevier B.V. All rights reserved.

Strong erbium luminescence in the near-infrared telecommunication window

A new type of near-infrared emitting rare-earth complex has been synthesised, consisting of three bis(perfluoroalkylsulfonyl)imide ligands and one 1,10-phenanthroline molecule. The chelate rings formed by the rare-earth ion and the bidentate ligands do not contain any carbon atoms and can hence be considered as 'inorganic' chelate rings. The absence of C-H stretching vibration modes in the first coordination sphere of the rare-earth ion and the presence of a light-harvesting moiety (1,10-phenanthroline) bound to the rare-earth ion result in a complex that can be efficiently excited and exhibits intense near-infrared luminescence. (C) 2004 Elsevier B.V. All rights reserved.

Family functioning during the diagnosis process in families with children on the autism spectrum,

While the causes of autism spectrum disorder (ASD) still are not fully understood, increasingly research focuses on interventions and treatment of children diagnosed with ASD. Considerably less attention is paid to family systems, family functioning, and family needs. This paper takes a family system perspective exploring how families with children on the autism spectrum function during the particularly stressful period of the diagnosis process and thereafter. Recommendations made in this paper include the need for empirical studies that address in detail family systems, family needs, the assessment and diagnostic process, service provision, social support networks, and additional stressful life events. Furthermore, the development of a family functioning assessment tools is called for in order to promote child-family-centred assessment and intervention. Details of an ongoing comparative study are outlined that will make a contribution to family studies and autism research field with a specific focus on the diagnosis

Experiences of parents during diagnosis and forward planning for children with Autism Spectrum Disorder.

Background For families of children diagnosed with autism spectrum disorder (ASD) getting a diagnosis is a traumatic experience on which future care and education plans for the child depend. In this paper parental experiences of diagnosis and forward planning for children with ASD are reported. Method This paper is part of a large cross-sectional study conducted in Northern Ireland and the Republic of Ireland that assessed the needs and experiences of parents of children diagnosed with ASD. Questionnaires were designed and completed by 95 parents, reporting on 100 children, as well as 67 multi-disciplinary professionals. Results Findings confirm that diagnostic and planning processes are extremely stressful for parents, that statutory diagnosis takes a long time, that care and education plans do not include full parental participation, and that reviews of plans do not consistently include intervention data. Conclusion Policy and practice implications of these findings are important for future revisions of diagnostic tools and manuals.

Living with children diagnosed with Autism Spectrum Disorder: Parental and professional views

The number of children diagnosed with an autistic spectrum disorder (ASD) is rising and is now thought to be as high as 1:100. While the debate about best treatment continues, the effects of having a child diagnosed with ASD on family life remain relatively unexplored. This article, by Karola Dillenburger of Queens University Belfast, Mickey Keenan of the University of Ulster, Alvin Doherty from the Health Service Executive Western Region, Tony Byrne of Parents’ Education as Autism Therapists (PEAT) and Stephen Gallagher of the University of Ulster, sets out to adjust that balance. Drawing upon data from a comprehensive study of parental needs, these authors argue that parental and professional views do not always concur; that families make extraordinary sacrifices; that siblings are affected; and that parents are under tremendous stress. Parents argue that educational and social service supports are not efficient and that they are forced to rely largely on support from within the family or from friends. In particular, some important differences between parental and professional perceptions became apparent in relation to interventions based on Applied Behaviour Analysis (ABA). The authors of this article propose that these differences need to be taken seriously by teachers and other professionals as well as by policy-makers.

Phylloseptin-1 (PSN-1) from Phyllomedusa sauvagei skin secretion: a novel broad-spectrum antimicrobial peptide with antibiofilm activity

Amphibian skin secretions have proven to be rich sources of antimicrobial peptides that are proposed to be fundamental components of the innate immune system. As amphibian skin is a multi-functional organ playing, among other things, a crucial role in respiration, it has been deemed that a core biological role for such peptides is control of microbial flora on this surface. To date, however, antimicrobial efficacy has been universally determined by means of establishing minimum inhibitory concentrations (MICs) using planktonic organisms rather than those within a biofilm such as would occur on this exposed surface. Here we describe the identification and structural characterisation of a novel 19 amino acid residue antimicrobial peptide of the phylloseptin family, named PSN-1, from the skin secretion of the waxy monkey frog, Phyllomedusa sauvagei. PSN-1 displayed broad-spectrum activity against a range of planktonic organisms with a high potency (MIC 5 µM) against Staphylococcus aureus. In a specific bioassay with the same organism grown as a biofilm, the minimal biofilm eradication concentration (MBEC) was found to be of the same high potency (5 µM). The present data would suggest that evaluation of actions and potency of amphibian skin secretion antimicrobial peptides might best be achieved by evaluating MBEC rather than MIC using planktonic organisms and that data arising from such studies may have more biological relevance in reflecting the purpose for which they have evolved through natural selection.

ABA-Based Programs for Children Diagnosed With Autism Spectrum Disorder: Parental and Professional Experiences at School and at Home

Having a child diagnosed with Autism Spectrum Disorder (ASD) poses a range of challenges to families, many of which can be addressed through appropriate intervention. A study of parental (n = 95) and professional (n = 67) experiences was carried out in relation to two settings: (a) schools that provided intensive interventions based on the science of Applied Behavior Analysis (ABA), and (b) non-intensive ABA-based home programs. Results show that parents whose children attend ABA-based schools were generally more satisfied with their child's educational provision, monitoring procedures, and level of staff training, than parents who were not offered ABA-based education in schools. © 2012 Copyright Taylor and Francis Group, LLC.