What are the relative merits of interventions used to reduce the occurrences of disruptive vocalisation in persons with dementia? - a systematic review.

Introduction: Dementia is a major health issue, and many people who have the progressive disease express disruptive vocalisation. These behaviours place large burdens on carers, family and on the individual themselves.

Background: This systematic review explored the use of interventions that could be used within practice to reduce the occurrences of disruptive vocalisation in people with dementia.

Assessment of chemical and biochemical stabilization of organic C in soils from the long-term experiments at Rothamsted (UK).

Biological and chemical stabilization of organic C was assessed in soils sampled from the long-term experiments at Rothamsted (UK), representing a wide range of carbon inputs and managements by extracting labile, non-humified organic matter (NH) and humic substances (HS). Four sequentially extracted humic substances fractions of soil organic matter (SOM) were extracted and characterized before and after a 215-day laboratory incubation at 25 degrees C from two arable soils, a woodland soil and an occasionally stubbed soil. The fractions corresponded to biochemically stabilised SOM extracted in 0.

The first proton NMR imaging of ice: stray-field imaging and relaxation studies.

A proton magnetic resonance image of ice was observed with the stray-field (STRAFI) technique. A preliminary study of proton relaxation times was performed in water and ice, at different temperatures. For example, a value of 3.

Stray field nuclear magnetic resonance of soil water: development of a new, large probe and preliminary results.

Development, characterization, and preliminary results of a recent technique capable of local measurements of pore-size distribution by a spatially resolved low resolution nuclear magnetic resonance (NMR) technique are described. Potential environmental uses include studying the change in pore-size distribution caused by surface compaction, which influences surface runoff, and obtaining information on the physical state of non-aqueous compounds in porous materials, which should aid the selection of appropriate soil remediation methods. Stray field (STRAFI) imaging is an NMR technique that allows distortion-free imaging of materials with short NMR relaxation times.

Multinuclear magnetic resonance analysis of two humic acid fractions from lowland rice soils.

To determine the effects of intensive cropping of tropical lowland rice (Oryza sativa L.) and the associated long-term soil submergence on chemical properties of soil organic matter, we used solid-state 13C and 15N and solution 31P nuclear magnetic resonance (NMR) spectroscopy to analyze the labile mobile humic acid (MHA) and the more recalcitrant calcium humate (CaHA) fractions extracted from a series of soils supporting several long-term field experiments in the Philippines. The soils varied mainly in degree of submergence and cropping intensity, ranging from a rainfed rice field without soil submergence to irrigated double- and triple-cropped fields in which soil remains submerged almost all year long.

GAMMA simulations of stray field responses: slice thickness and pulse calibration.

A stray field (STRAFI) module has been added to the GAMMA magnetic resonance simulation platform in order to facilitate computational investigations of NMR experiments in large static field gradients that are on the order of 50 T/m. The package has been used to examine system response during echo trains generated by the application of shaped pulses. The associated echo amplitude maxima and effective slice thickness are presented.

Phosphorus-31 solid-state nmr in high-field gradients: prospects for imaging bone using the long echo-train summation technique (LETS).

Stray-field techniques are reported for 31P studies of solids for a variety of compounds including bone, bone meal and calcium hydroxyapatite. Long Hahn echo trains produced by the application of many pulses were used as in the long echo-train summation technique. Double-resonance enhancements of 31P by use of both direct and indirect experiments were attempted on a sample of NH4PF6:31P[19F] double resonance produced, at most, a 26% increase in the initial level of the 31P echo signal.

STRAFI-NMR studies of water transport in soil.

1-D STRAFI (STRAy FIeld) imaging is used to study water distribution in a sandy loam. The matric potential of the soil can be varied during acquisition of 1-D profiles. Results at a range of potentials are presented showing both the equilibrium distribution and the evolution of the profile following an abrupt change in matric potential.

Calibration of the stray field gradient by a heteronuclear method and by field profiling.

Heteronuclear and field-profiling stray field (STRAFI) techniques are used to calibrate the STRAFI gradient. Both methods compare very favorably indeed with the conventional method of calibration which uses a standard with a known self-diffusion constant. The distinct advantages of the techniques presented here are that the constraints on both sample purity and sample temperature that are inherent to the conventional method are completely eliminated.

Hahn-echoes from 14N in solids by the stray-field method: prospects for imaging using Long Echo-Train Summation.

We have observed Hahn-echoes resulting from Powles-Mansfield pulse-sequences for a variety of nitrogen containing solids which exhibit a range of 14N electric quadrupole coupling constants (Cq) from 0 to 4.9 MHz. Long echo-decays were frequently obtained which allowed the collection of many echoes in one echo-train, so that the method of Long Echo-Train Summation (LETS), could be used to accumulate signal.

T1-weighting of Hahn echo-trains in the stray-field for deuterium: prospects for imaging using long echo-train summation.

Hahn-echoes have been observed in stray-field gradients of 37.5 T/m and 74.5 T/m for deuterium in heavy water in a number of forms: liquid, ice, and coordinated in solid copper sulfate and silica gel.

Stray-field imaging of quadrupolar nuclei of half integer spin in solids.

A report is presented on the observation of Hahn echoes from the following quadrupolar nuclei of half integer spin (I) in polycrystalline solids in the large static magnetic field gradient (37.5 T/m) which exists in the fringe field of a superconducting solenoid: 7Li, 23Na, 11B, 65Cu (I = 3/2); 27Al (I = 5/2); 51V, 59Co (I = 7/2); and 115In (I = 9/2). 23Na echo-trains from NaCl (with non-selective excitation) and from Na2SO4 (with selective excitation) are compared quantitatively for two different RF pulse sequences: 90x-(tau-90y-tau-echo-)n and 90x-(tau-90x-tau-echo-)n.

A convenient method for calibration of the pulse-length in high field-gradients using Hahn echo-trains.

A new method is presented for calibration of the pulse-length in the case that the sample, which can be either a liquid or a solid, is placed in a high field-gradient such as it experiences in the stray-, fringe-field of a solenoid. The method employs a pulse-train, with a constant phase, of the form alpha X-tau-(alpha X-tau-echo-tau-)n. This produces Hahn echoes which have variable phase in the form of phase-alternations along the echo-train.

1H and 19F magnetic resonance imaging of solid paramagnetic compounds using large magnetic field gradients and Hahn echoes.

1H and 19F spatially resolved echo trains of a number of paramagnetic solids with apparent magnetic moments as high as 10 Bohr magnetons have been successfully obtained in the 58 T m-1 fringe-field gradient of a 9.4 T superconducting magnet by the use of Hahn echoes. Complexes studied include hydrates of Ni(II), Fe(III), Mn(II), and the anhydrous fluorides of Ti(III), Co(II) and Mn(II).

Hahn Spin Echoes in Large Static Gradients Following a Series of 90° Pulses.

The intensities of the Hahn spin echoes produced by a series of 90° pulses applied to a sample in large static field gradients are calculated. Static gradients are important because they can be very much larger than pulsed field gradients and echoes can be collected without recovery time problems. One application is for imaging using the stray field of a magnet (STRAFI).

Magnetic susceptibility effects in imaging: distortion-free images of plant tissue in soil.

Magnetic susceptibility effects (MSE) in NMR spectra are well known, and indeed the NMR technique has frequently been applied to measure magnetic susceptibility. In the case of imaging, MSE can lead to image distortion when the sample is heterogeneous. We have performed experiments on a soil sample (iron content approximately 2%) containing plant tissue which gave a NMR signal that was spread over about 15 kHz in the 1H spectrum.

Betaine metabolism in human neonates and developing rats.

Proton nuclear magnetic resonance spectroscopy has been used to demonstrate the presence of high concentrations of betaine (up to 0.75 mol/mol creatinine) in the urine of normal healthy human neonates. Betaine is not normally excreted in adults.

The conformation of gramicidin A in dimethylsulphoxide solution. A full analysis of the one- and two-dimensional 1H, 13C, and 15N nuclear-magnetic-resonance spectra.

The combined application of one- and two-dimensional high-field NMR techniques has led to the first assignment of the 1H, 13C, and 15N spectra of the pentadecapeptide gramicidin A in dimethylsulphoxide solution. The 62.9-MHz and 100.

Qualitative aspects of hydrogen-deuterium exchange in the 1H, 13C, and 15N nuclear magnetic resonance spectra of viomycin in aqueous solution.

The 1H, 13C, and 15N high field nuclear magnetic resonance spectra of the cyclic peptide viomycin have been fully assigned using homo- and heteronuclear double resonance experiments and pH effects. In addition it is shown how the two- and three-bond H-D isotope effects upon carbonyl resonances may assist in their assignment. The resistance to exchange with solvent water of the amide proton involved in the transannular hydrogen bond is observed directly in the 1H spectra, via the isotope effect on a carbonyl resonance in the 13C spectra, and via the one-bond 1H couppling in the 15N spectra.

Theory and practice for studies for peptides by 15N nuclear magnetic resonance at natural abundance: gramicidin S.

The low-abundance isotope of nitrogen, 15N, is now accessible to study by the latest high resolution nuclear magnetic resonance techniques. Structure and motion in polypeptides of moderate size may now be usefully investigated in this way.

Nuclear magnetic resonance and infrared studies of N15-substituted trimethylsilyl-, -germyl-, and -stannylanilines. A Test of (p->d)-pi interactions in group IV nitrogen bonds.

Infrared and proto n magnetic resonance spectra of the aniline-N14 and -N15 isotopomers and their N-trimethylsilyl, -germyl, and -stannyl derivatives have been measured and compared. Nmr assignments have been checked by comparisons of proton spectra at 60 and 100 Mcps; by proton-N15 heteronuclear experiments at 9400 G; and by observation of N15 satellites. The one-bond "5-H couplings can be interpreted (on the assumption of a dominant Fermi spin-spin interaction, small radial variations for nitrogen wave functions, and equal distributions of s character in the sigma bonds) in terms of pyramidal arrangements of bonds at nitrogen.