3D Printable Polymer Electrolytes for Ionic Conduction based on Protic Ionic Liquids.

A range of protic ionic liquids (PILs) based on tri-n-alkylammonium cations and mesylate/triflate anions were incorporated into a polymer matrix to form ionogels (IGs). These systems were investigated for their thermal and electrochemical behaviour, as well as under the aspect of ion motion via PFG-NMR. The ionic conductivities of the ILs/IGs are in the range of 10‑4 - 10-3 Scm-1 at elevated temperatures and the diffusion coefficients were around 10‑11 m2s-1.

A New Solid-State Proton Conductor: The Salt Hydrate Based on Imidazolium and 12-Tungstophosphate.

We report the structure and charge transport properties of a novel solid-state proton conductor obtained by acid-base chemistry via proton transfer from 12-tungstophosphoric acid to imidazole. The resulting material (henceforth named ImidWP) is a solid salt hydrate that, at room temperature, includes four water molecules per structural unit. To our knowledge, this is the first attempt to tune the properties of a heteropolyacid-based solid-state proton conductor by means of a mixture of water and imidazole, interpolating between water-based and ionic liquid-based proton conductors of high thermal and electrochemical stability.

Composite Nafion Membranes with CaTiO Additive for Possible Applications in Electrochemical Devices.

A composite membrane based on a Nafion polymer matrix incorporating a non-stoichiometric calcium titanium oxide (CaTiO) additive was synthesized and characterized by means of thermal analysis, dynamic mechanical analysis, and broadband dielectric spectroscopy at different filler contents; namely two concentrations of 5 and 10 wt.% of the CaTiO additive, with respect to the dry Nafion content, were considered. The membrane with the lower amount of additive displayed the highest water affinity and the highest conductivity, indicating that a too-high dose of additive can be detrimental for these particular properties.

Protic Ionic Liquids Based on the Alkyl-Imidazolium Cation: Effect of the Alkyl Chain Length on Structure and Dynamics.

Protic ionic liquids are known to form extended hydrogen-bonded networks that can lead to properties different from those encountered in the aprotic analogous liquids, in particular with respect to the structure and transport behavior. In this context, the present paper focuses on a wide series of 1-alkyl-imidazolium bis(trifluoromethylsulfonyl)imide ionic liquids, [HC Im][TFSI], with the alkyl chain length ( n) on the imidazolium cation varying from ethyl ( n = 2) to dodecyl ( n = 12). A combination of several methods, such as vibrational spectroscopy, wide-angle X-ray scattering (WAXS), broadband dielectric spectroscopy, and H NMR spectroscopy, is used to understand the correlation between local cation-anion coordination, nature of nanosegregation, and transport properties.

Conductivity-Relaxation Relations in Nanocomposite Polymer Electrolytes Containing Ionic Liquid.

In this study, we have used nanocomposite polymer electrolytes, consisting of poly(ethylene oxide) (PEO), δ-AlO nanoparticles, and lithium bis(trifluoromethanesolfonyl)imide (LiTFSI) salt (with 4 wt % δ-AlO and PEO:Li ratios of 16:1 and 8:1), and added different amounts of the ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethanesolfonyl)imide (BMITFSI). The aim was to elucidate whether the ionic liquid is able to dissociate the Li-ions from the ether oxygens and thereby decouple the ionic conductivity from the segmental polymer dynamics. The results from DSC and dielectric spectroscopy show that the ionic liquid speeds up both the segmental polymer dynamics and the motion of the Li ions.

Dynamics of aqueous binary glass-formers confined in MCM-41.

Dielectric permittivity measurements were performed on water solutions of propylene glycol (PG) and propylene glycol monomethyl ether (PGME) confined in 21 Å pores of the silica matrix MCM-41 C10 in wide frequency (10(-2)-10(6) Hz) and temperature (130-250 K) ranges. The aim was to elucidate how the formation of large hydrogen bonded structural entities, found in bulk solutions of PGME, was affected by the confined geometry, and to make comparisons with the dynamic behavior of the PG-water system. For all solutions the measurements revealed four almost concentration independent relaxation processes.

Brownian motion of single glycerol molecules in an aqueous solution as studied by dynamic light scattering.

Aqueous solutions of glycerol are investigated by dynamic light scattering (DLS) over the whole concentration range (10-98 wt.% water) and in the temperature range 283-303 K. The measurements reveal one slow relaxation process in the geometry of polarized light scattering.

Anomalous dynamics of aqueous solutions of di-propylene glycol methylether confined in MCM-41 by quasielastic neutron scattering.

The molecular dynamics of solutions of di-propylene glycol methylether (2PGME) and H2O (or D2O) confined in 28 Å pores of MCM-41 have been studied by quasielastic neutron scattering and differential scanning calorimetry over the concentration range 0-90 wt.% water. This system is of particular interest due to its pronounced non-monotonic concentration dependent dynamics of 2PGME in the corresponding bulk system, showing the important role of hydrogen bonding for the dynamics.

Glass transition and relaxation dynamics of propylene glycol-water solutions confined in clay.

The molecular dynamics of aqueous solutions of propylene glycol (PG) and propylene glycol methylether (PGME) confined in a two-dimensional layer-structured Na-vermiculite clay has been studied by broadband dielectric spectroscopy and differential scanning calorimetry. As typical for liquids in confined geometries the intensity of the cooperative α-relaxation becomes considerably more suppressed than the more local β-like relaxation processes. In fact, at high water contents the calorimetric glass transition and related structural α-relaxation cannot even be observed, due to the confinement.

Effect of dietary levels of decorticated cow pea (Vigna unguiculata) supplemented with molasses on broiler chicks performance and carcass traits.

Manny legumes are used extensively as animal feed. This study was conducted to look at the effects of decorticated cow pea seeds based diets supplemented with molasses on broiler performance and carcass traits. A total of 240 unsexed one-day old broiler chicks (Ross 308) were used .

Different behavior of water in confined solutions of high and low solute concentrations.

Water-glycerol solutions confined in 21 Å pores of the silica matrix MCM-41 C10 have been studied using differential scanning calorimetry (DSC) and broadband dielectric spectroscopy (BDS). The results suggest a micro-phase separation caused by the confinement. Likely the water molecules coordinate to the hydroxyl surface groups of the pores, leaving most of the glycerol molecules in the centre of the pores.

Long-range diffusion in xylitol-water mixtures.

Dynamic light scattering (DLS) and small-angle neutron scattering (SANS) were employed to study mixtures of xylitol and water. The results were also related to a previous dielectric relaxation study on the same system. In the temperature range of the DLS measurements the viscosity related structural (α) relaxation is too fast to be observed on the experimental time scale, but a considerably slower exponential and hydrodynamic relaxation process is clearly observable in the polarized light scattering data.

Calorimetric and relaxation properties of xylitol-water mixtures.

We present the first broadband dielectric spectroscopy (BDS) and differential scanning calorimetry study of supercooled xylitol-water mixtures in the whole concentration range and in wide frequency (10(-2)-10(6) Hz) and temperature (120-365 K) ranges. The calorimetric glass transition, T(g), decreases from 247 K for pure xylitol to about 181 K at a water concentration of approximately 37 wt. %.

Clinical review: The effect of vitamin D on falls: a systematic review and meta-analysis.

Context: Vitamin D affects bone and muscle health and likely reduces the risk of falls in the elderly.

Objective: The aim of this systematic review is to summarize the existing evidence on vitamin D use and the risk of falls.

Data Sources: We searched electronic databases from inception through August 2010.

Vitamin D and cardiovascular outcomes: a systematic review and meta-analysis.

Context: Several studies found association between vitamin D levels and hypertension, coronary artery calcification, and heart disease.

Objective: The aim of this study was to summarize the evidence on the effect of vitamin D on cardiovascular outcomes.

Design And Methods: We searched electronic databases from inception through August 2010 for randomized trials.

Clinical review: Adult height in patients with congenital adrenal hyperplasia: a systematic review and metaanalysis.

Context: Treatment for patients with congenital adrenal hyperplasia (CAH) may affect the final height of these patients.

Objective: Our objective was to determine the distribution of achieved height in patients with classic CAH diagnosed at infancy or early childhood and treated with glucocorticoids.

Data Sources: We searched MEDLINE, EMBASE, Cochrane Library, ISI Web of Science, and Scopus through September 2008; the reference sections of included studies; and expert files.

Prenatal dexamethasone use for the prevention of virilization in pregnancies at risk for classical congenital adrenal hyperplasia because of 21-hydroxylase (CYP21A2) deficiency: a systematic review and meta-analyses.

Context: Prenatal treatment with dexamethasone to prevent virilization in pregnancies at risk for classical congenital adrenal hyperplasia (CAH) remains controversial.

Objective: To conduct a systematic review and meta-analyses of studies that evaluated the effects of dexamethasone administration during pregnancies at risk for classical CAH because of 21-hydroxylase deficiency (CYP21A2).

Data Sources: We searched MEDLINE, EMBASE, and Cochrane CENTRAL from inception through August 2009.

Activation of Akt is increased in the dysplasia-carcinoma sequence in Barrett's oesophagus and contributes to increased proliferation and inhibition of apoptosis: a histopathological and functional study.

Background: The incidence of oesophageal adenocarcinoma is increasing rapidly in the developed world. The serine-threonine protein kinase and proto-oncogene Akt has been reported to regulate proliferation and apoptosis in several tissues but there are no data on the involvement of Akt in oesophageal carcinogenesis. Therefore we have examined the activation of Akt in Barrett's oesophagus and oesophageal adenocarcinoma and the functional effects of Akt activation in vitro.