Mealtime and patient factors associated with meal completion in hospitalised older patients: An exploratory observation study.

AIMS AND OBJECTIVES: To examine mealtime and patient factors associated with meal completion among hospitalised older patients. We also considered contextual factors such as staffing levels and ward communication. BACKGROUND: Sub-optimum nutrition is a modifiable risk factor for hospital associated decline (HAD) in older patients. Yet, the quality of mealtime experiences can be overlooked within ward routinised practice. DESIGN: Cross sectional, descriptive observation study. METHODS: We undertook structured observation of mealtimes examining patient positioning, mealtime set-up and feeding assistance. The outcome was meal completion categorised as 0, 25%, 50%, 75% or 100%. Data were collected on patient characteristics and ward context. We used mixed-effects ordinal regression models to examine patient and mealtime factors associated with higher meal completion producing odds ratios (OR) and 95% confidence intervals (CI). The study was reported as per STROBE guidelines. RESULTS: We included 60 patients with a median age of 82 years (IQR 76-87) and clinical frailty score of 5 IQR (4-6). Of the 279 meals, 51% were eaten completely, 6% three quarters, 15% half, 18% a quarter and 10% were not eaten at all. Mealtime predictors with a weak association with less-meal completion were requiring assistance, special diets, lying in bed, and red tray (indicator of nutrition risk), but were not statistically significant. Significant patient-level factors were higher values for frailty (OR 0.34 [0.11-1.04]) and Malnutrition Universal Screening Tool (OR 0.22 [0.08-0.62]). The average nurse-to-patient ratio was 1:5.5. CONCLUSION: Patient factors were the strongest predictors for meal completion, but mealtime factors had a subtle influence. The nursing teams' capacity to prioritise mealtimes above competing demands is important as part of a comprehensive nutrition strategy. RELEVANCE TO CLINICAL PRACTISE: Nurses are central to optimising nutrition for frail older patients. It requires ward leadership to instil a culture of prioritising assisted mealtimes, improved communication, greater autonomy to tailor nutrition strategies and safe staffing levels.

Spectrally tunable chiral Bragg reflectors for on-demand beam generation.

We demonstrate the generation of spectrally tunable phase-dependent wavefronts, using the 2D Airy as the primary test case, via a polymer-stabilized cholesteric liquid crystal (PSCLC) element. Specifically, we use a novel spatial light modulator (SLM) based projection system to photo-align the initial helix angle landscape of the PSCLC so that it imparts the appropriate cubic phase profile to the reflected beam. This element is spectrally selective, with a reflection bandwidth of ≈ 100 nm, and electrically tunable from λ = 530 nm to 760 nm. Under both green and red laser illumination, the element is shown to conditionally form an Airy beam depending on the position of the electrically tailored reflection band. We briefly demonstrate the generality of this approach by producing PSCLC elements which form a computer-generated hologram and a higher-order Mathieu beam.

Cerebellar Growth Impairment Characterizes School-Aged Children Born Preterm without Perinatal Brain Lesions.

BACKGROUND AND PURPOSE: Infants born preterm are commonly diagnosed with structural brain lesions known to affect long-term neurodevelopment negatively. Yet, the effects of preterm birth on brain development in the absence of intracranial lesions remain to be studied in detail. In this study, we aim to quantify long term consequences of preterm birth on brain development in this specific group. MATERIALS AND METHODS: Neonatal cranial sonography and follow-up T1-weighted MR imaging and DTI were performed to evaluate whether the anatomic characteristics of the cerebrum and cerebellum in a cohort of school-aged children (6-12 years of age) were related to gestational age at birth in children free of brain lesions in the perinatal period. RESULTS: In the cohort consisting of 36 preterm (28-37 weeks' gestational age) and 66 term-born infants, T1-weighted MR imaging and DTI at 6-12 years revealed a reduction of cerebellar white matter volume (ß = 0.387, P < .001), altered fractional anisotropy of cerebellar white matter (ß = -0.236, P = .02), and a reduction of cerebellar gray and white matter surface area (ß = 0.337, P < .001; ß = 0.375, P < .001, respectively) in relation to birth age. Such relations were not observed for the cerebral cortex or white matter volume, surface area, or diffusion quantities. CONCLUSIONS: The results of our study show that perinatal influences that are not primarily neurologic are still able to disturb long-term neurodevelopment, particularly of the developing cerebellum. Including the cerebellum in future neuroprotective strategies seems therefore essential.

Curvature by design and on demand in liquid crystal elastomers.

The shape of liquid crystalline elastomers (LCEs) with spatial variation in the director orientation can be transformed by exposure to a stimulus. Here, informed by previously reported analytical treatments, we prepare complex spiral patterns imprinted into LCEs and quantify the resulting shape transformation. Quantification of the stimuli-induced shapes reveals good agreement between predicted and experimentally observed curvatures. We conclude this communication by reporting a design strategy to allow LCE films to be anchored at their external boundaries onto rigid substrates without incurring internal, mechanical-mismatch stresses upon actuation, a critical advance to the realization of shape transformation of LCEs in practical device applications.

Interstitial Oxide Ion Distribution and Transport Mechanism in Aluminum-Doped Neodymium Silicate Apatite Electrolytes.

Rare earth silicate apatites are one-dimensional channel structures that show potential as electrolytes for solid oxide fuel cells (SOFC) due to their high ionic conductivity at intermediate temperatures (500-700 °C). This advantageous property can be attributed to the presence of both interstitial oxygen and cation vacancies, that create diffusion paths which computational studies suggest are less tortuous and have lower activation energies for migration than in stoichiometric compounds. In this work, neutron diffraction of Nd(28+x)/3AlxSi6-xO26 (0 ≤ x ≤ 1.5) single crystals identified the locations of oxygen interstitials, and allowed the deduction of a dual-path conduction mechanism that is a natural extension of the single-path sinusoidal channel trajectory arrived at through computation. This discovery provides the most thorough understanding of the O(2-) transport mechanism along the channels to date, clarifies the mode of interchannel motion, and presents a complete picture of O(2-) percolation through apatite. Previously reported crystallographic and conductivity measurements are re-examined in the light of these new findings.

Crystal chemical characteristics of ellestadite-type apatite: implications for toxic metal immobilization.

The ellestadite apatites Ca10[(SiO4)x(PO4)6-2x(SO4)x]Cl2 were studied by powder X-ray and neutron diffraction to establish baseline crystallographic data. These synthetic materials, unlike mineral specimens that are well equilibrated, show no Si/P/S ordering and conform to P63/m symmetry. Phosphate-rich ellestadites where 0 ≤ x ≤ 1 show chemical stability towards Toxicity Characterization Leaching Procedure (TCLP) testing and are potential immobilization matrices for mixed toxic metal wastes.

Gastric perforation in an adult male following nasogastric intubation.

INTRODUCTION: Spontaneous gastric perforation is a well known surgical emergency which carries significant mortality and morbidity. Well documented causes in adults include peptic ulcer disease, drugs such as non-steroidal and gastric malignancy. Iatrogenic causes still remain relatively rare. We report an interesting case of an acutely unwell young man who developed gastric perforation secondary to nasogastric intubation. CASE REPORT: A 32 year old man initially treated for gastroenteritis underwent laparotomy for acute intra-abdominal bleeding. This was found to be secondary to a ruptured left hepatic artery aneurysm which was subsequently embolised. Patient had multiple laparotomies, a nasogastric tube inserted at the second laparotomy was later found to be the cause of gastric perforation. On further investigation the patient's multiple aneurysms were histologically confirmed to be secondary to fibromuscular dysplasia (FMD). CONCLUSION: We present here a case of gastric perforation from a nasogastric tube in an adult male and discussed its relevance to the diagnosis of FMD. This case highlights the importance of having a high index of suspicion for this complication when managing patients with severe abdominal sepsis.

Continuous wave mirrorless lasing in cholesteric liquid crystals with a pitch gradient across the cell gap.

Despite numerous efforts, continuous wave (CW) lasing in dye doped, one-dimensional (1D) photonic bandgap cholesteric liquid crystal (CLC) structures has not been previously reported, to our knowledge. Here we report on the observation of lasing in such structures under both coherent (laser) and incoherent (LED) CW light excitation. To achieve this effect, we used a 1D-photonic bandgap structure made of a polymer stabilized CLC with a pitch gradient across the cell thickness. A spectral reflectivity profile of such a CLC structure reveals local minima in the area within a photonic stopband and close to it. The realization of lasing pumped by low power CW light sources opens the possibility of all-organic, compact, tunable CW lasers for display and medical applications.

Apatite germanates doped with tungsten: synthesis, structure, and conductivity.

High oxygen content apatite germanates, La(10)Ge(6-x)W(x)O(27+x), have been prepared by doping on the Ge site with W. In addition to increasing the oxygen content, this doping strategy is shown to result in stabilisation of the hexagonal lattice, and yield high conductivities. Structural studies of La(10)Ge(5.5)W(0.5)O(27.5) show that the interstitial oxygen sites are associated to a different degree with the Ge/WO(4) tetrahedra, leading to five coordinate Ge/W and significant disorder for the oxygen sites associated with these units. Raman spectroscopy studies suggest that in the case of the WO(5) units, the interstitial oxygen is more tightly bonded and therefore not as mobile as in the case of the GeO(5) units, thus not contributing significantly to the conduction process.

Microwave synthesis of noncentrosymmetric BaTiO3 truncated nanocubes for charge storage applications.

Truncated nanocubes of barium titanate (BT) were synthesized using a rapid, facile microwave-assisted hydrothermal route. Stoichiometric composition of pellets of nanocube BT powders was prepared by two-stage microwave process. Characterization by powder XRD, Rietveld refinement, SEM, TEM, and dielectric and polarization measurements was performed. X-ray diffraction revealed a polymorphic transformation from cubic Pm3̅m to tetragonal P4mm after 15 min of microwave irradiation, arising from titanium displacement along the c-axis. Secondary electron images were examined for nanocube BT synthesis and annealed at different timings. Transmission electron microscopy showed a narrow particle size distribution with an average size of 70 ± 9 nm. The remanence and saturation polarization were 15.5 ± 1.6 and 19.3 ± 1.2 µC/cm(2), respectively. A charge storage density of 925 ± 47 nF/cm(2) was obtained; Pt/BT/Pt multilayer ceramic capacitor stack had an average leakage current density of 5.78 ± 0.46 × 10(-8) A/cm(2) at ±2 V. The significance of this study shows an inexpensive and facile processing platform for synthesis of high-k dielectric for charge storage applications.

Crystal structure refinements of the 2H and 2M pseudomorphs of ferric carbonate-hydroxyapatite.

The crystal structures of the ferric carbonate-hydroxyapatite (Fe-CHAp) and oxyapatite (Fe-OAp) pseudomorphs were investigated by powder neutron diffraction and Fourier transform infrared spectroscopy. At low iron loadings, Fe-CHAp (x = 0.1) is A-B type carbonate apatite-2H, where atmospheric CO(2) displaces tunnel hydroxyl and framework phosphate (Ca(2+) + 2PO(4)(3-) --> square(Ca) + 2CO(3)(2-) and Ca(2+) + OH(-) --> Fe(3+) + CO(3)(2-)), while Fe-CHAp (x = 0.2) is A type carbonate apatite-2M. For high iron loadings (x = 0.5), near the solubility limit, Fe(3+) incorporation includes concomitant oxidation of hydroxyl groups (Ca(2+) + OH(-) --> Fe(3+) + O(2-)). The discontinuity in the lattice metric at x approximately 0.2 together with a progressive reduction of OH(-) and CO(3)(2-), substantiates these incorporation mechanisms. The general formula of Fe-CHAp is [Ca(4-x)(F)Fe(x)][Ca(6-y)(T) square(y)][(PO(4))(6-y)(CO(3))(y)][(OH(4))(2-x)(CO(3))(x)] (0 < or = x < or = 0.2, 0 < or = y < or = 0.2) and Fe-OAp is [Ca(3.8)(F)Fe(0.2)][Ca(6-x)(T)Fe(x)][(PO(4))][O(0.2+x)(OH)(1.8-x)] (0 < x < or = 0.3). These new data are placed in the context of earlier crystallographic studies, with the Ca(I)O(6) metaprism twist angle (phi) shown to be a reliable indicator of symmetry, such that for phi(max) > 27.(0) degrees, monoclinic and triclinic structures are preferable.

Polysomatic apatites.

Certain complex structures are logically regarded as intergrowths of chemically or topologically discrete modules. When the proportions of these components vary systematically a polysomatic series is created, whose construction provides a basis for understanding defects, symmetry alternation and trends in physical properties. Here, we describe the polysomatic family A(5N)B(3N)O(9N + 6)X(Ndelta) (2 < or = N < or = infinity) that is built by condensing N apatite modules (A(5)B(3)O(18)X(delta)) in configurations to create B(n)O(3n + 1) (1 < or = n < or = infinity) tetrahedral chains. Hydroxyapatite [Ca(10)(PO(4))(6)(OH)(2)] typifies a widely studied polysome where N = 2 and the tetrahedra are isolated in A(10)(BO(4))(6)X(2) compounds, but N = 3 A(15)(B(2)O(7))(3)(BO(4))(3)X(3) (ganomalite) and N = 4 A(20)(B(2)O(7))(6)X(4) (nasonite) are also known, with the X site untenanted or partially occupied as required for charge balance. The apatite modules, while topologically identical, are often compositionally or symmetrically distinct, and an infinite number of polysomes is feasible, generally with the restriction being that an A:B = 5:3 cation ratio be maintained. The end-members are the N = 2 polysome with all tetrahedra separated, and N = infinity, in which the hypothetical compound A(5)B(3)O(9)X contains infinite, corner-connected tetrahedral strings. The principal characteristics of a polysome are summarized using the nomenclature apatite-(A B X)-NS, where A/B/X are the most abundant species in these sites, N is the number of modules in the crystallographic repeat, and S is the symmetry symbol (usually H, T, M or A). This article examines the state-of-the-art in polysomatic apatite synthesis and crystallochemical design. It also presents X-ray and neutron powder diffraction investigations for several polysome chemical series and examines the prevalence of stacking disorder by electron microscopy. These insights into the structure-building principles of apatite polysomes will guide their development as functional materials.

Pseudomorphic 2A--> 2M--> 2H phase transitions in lanthanum strontium germanate electrolyte apatites.

Apatite-like materials are of considerable interest as potential solid oxide fuel cell electrolytes, although their structural vagaries continue to attract significant discussion. Understanding these features is crucial both to explain the oxide ion conduction process and to optimise it. As the composition of putative P6(3)/m apatites with ideal formula [A(I)(4)][A(II)(6)][(BO(4))(6)][X](2) is varied the [A(I)(4)(BO(4))(6)] framework will flex to better accommodate the [A(II)(6)X(2)] tunnel component through adjustment of the A(I)O(6) metaprism twist angle (varphi). The space group theory prescribes that framework adaptation during phase changes must lead to one of the maximal non-isomorphic subgroups of P6(3)/m (P2(1), P2(1)/m, P1[combining macron]). These adaptations correlate with oxygen ion conduction, and become crucial especially when the tunnels are filled by relatively small ions and/or partially occupied, and if interstitial oxygens are located in the framework. Detecting and completely describing these lower symmetry structures can be challenging, as it is difficult to precisely control apatite stoichiometry and small departures from the hexagonal metric may be near the limits of detection. Using a combination of diffraction and spectroscopic techniques it is shown that lanthanum strontium germanate oxide electrolytes crystallise as triclinic (A), monoclinic (M) and hexagonal (H) bi-layer pseudomorphs with the composition ranges: [La(10-x)Sr(x)][(GeO(4))(5+x/2)(GeO(5))(1-x/2)][O(2)] (0

Robust gold-decorated silica-titania pebbles for low-temperature CO catalytic oxidation.

A deposition-precipitation (DP) process was used to prepare silica-titania core-shell pebbles decorated with nanocrystalline gold suitable for low-temperature catalytic oxidation of carbon monoxide (CO). The microstructure, phase content, crystallography, and catalytic activity were correlated with the pH (3-8), aging time (15, 30, 60 min), and heat treatment employed for gold crystallization (200-400 degrees C). A homogeneous metal distribution, high gold loading (3.7-4.4 wt %), and superior interfacial adhesion between gold and titania were obtained when the support pebbles were prepared at 600 degrees C, a temperature lower than that required for the anatase-to-rutile transformation. Nucleation and growth of {111} faceted gold was favored at mid-pH (6.4-8), while smaller crystals (<7.5 nm) were obtained at short aging times (

The crystal chemistry of the alkaline-earth apatites A(10)(PO(4))(6)Cu(x)O(y)(H)(z) (A = Ca, Sr and Ba).

The crystal chemistry of the cuprate apatites A(I)(4)A(II)(6)(PO(4))(6)Cu(x)O(y)(H)(z) (A = Ca, Sr and Ba) was investigated by powder X-ray (PXRD) and neutron diffraction (PND) and X-ray photoelectron spectroscopy (XPS). The refined crystal structures confirmed earlier X-ray diffraction studies that showed copper resides in the apatite channels and additionally, located hydrogen. For all materials copper is primarily divalent (Cu(2+)) but in the calcium and strontium analogues co-exists with minor Cu(3+). This is in contrast with a previous work where Cu(1+) and Cu(2+) were reported.

Virtual colonoscopy vs conventional colonoscopy in patients at high risk of colorectal cancer--a prospective trial of 150 patients.

OBJECTIVE: Virtual colonoscopy (VC)/CT colonography has advantages over the well-documented limitations of colonoscopy/barium enema. This prospective blinded investigative comparison trial aimed to evaluate the ability of VC to assess the large bowel, compared to conventional colonoscopy (CC), in patients at high risk of colorectal cancer (CRC). METHOD: We studied 150 patients (73 males, mean age 60.9 years) at high risk of CRC. Following bowel preparation, VC was undertaken using colonic insufflation and 2D-spiral CT acquisition. Two radiologists reported the images and a consensual agreement reached. Direct comparison was made with CC (performed later the same day). Interobserver agreement was calculated using the Kappa method. Postal questionnaires sought patient preference. RESULTS: Virtual colonoscopy visualized the caecum in all cases. Five (3.33%) VCs were classified as inadequate owing to poor distension/faecal residue. CC completion rate was 86%. Ultimately, 44 patients had normal findings, 44 had diverticular disease, 11 had inflammatory bowel disease, 18 had cancers, and 33 patients had 42 polyps. VC identified 19 cancers--a sensitivity and specificity of 100% and 99.2% respectively. For detecting polyps > 10 mm, VC had a sensitivity and specificity (per patient) of 91% and 99.2% respectively. VC identified four polyps proximal to stenosing carcinomas and extracolonic malignancies in nine patients (6%). No procedural complications occurred with either investigation. A Kappa score achieved for interobserver agreement was 0.777. CONCLUSION: Virtual colonoscopy is an effective and safe method for evaluating the bowel and was the investigation of choice amongst patients surveyed. VC provided information additional to CC on both proximal and extracolonic pathology. VC may become the diagnostic procedure of choice for symptomatic patients at high risk of CRC, with CC being reserved for therapeutic intervention, or where a tissue diagnosis is required.

The crystal chemistry of ferric oxyhydroxyapatite.

Ferric hydroxyapatites (Fe-HAp) and oxyapatites (Fe-OAp) of nominal composition [Ca(10-x)Fe(x)(3+)][(PO(4))(6)][(OH)(2-x)O(x)] (0 < or = x < or = 0.5) were synthesized from a coprecipitated precursor calcined under flowing nitrogen. The solid solubility of iron was temperature-dependent, varying from x = 0.5 after firing at 600 degrees C to x approximately 0.2 at 1000 degrees C, beyond which Fe-OAp was progressively replaced by tricalcium phosphate (Fe-TCP). Crystal size (13-116 nm) was controlled by iron content and calcination temperature. Ferric iron replaces calcium by two altervalent mechanisms in which carbonate and oxygen are incorporated as counterions. At low iron loadings, carbonate predominantly displaces hydroxyl in the apatite channels (Ca(2+) + OH(-) --> Fe(3+) + CO(3)(2-)), while at higher loadings, "interstitial" oxygen is tenanted in the framework (2Ca(2+) + (vac) --> 2Fe(3+) + O(2+)). Although Fe(3+) is smaller than Ca(2+), the unit cell dilates as iron enters apatite, providing evidence of oxygen injection that converts PO(4) tetrahedra to PO(5) trigonal bipyramids, leading to the crystal chemical formula [Ca(10-x)Fe(x)][(PO(4))(6-x/2)(PO(5))(x/2)][(OH)(2-y)O(2y)] (x < or = 0.5). A discontinuity in unit cell expansion at x approximately 0.2 combined with a substantial reduction of the carbonate FTIR fingerprint shows that oxygen infusion, rather than tunnel hydroxyl displacement, is dominant beyond this loading. This behavior is in contrast to ferrous-fluorapatite where Ca(2+) --> Fe(2+) aliovalent replacement does not require oxygen penetration and the cell volume contracts with iron loading. All of the materials were paramagnetic, but at low iron concentrations, a transition arising from crystallographic modification or a change in spin ordering is observed at 90 K. The excipient behavior of Fe-OAp was superior to that of HAp and may be linked to the crystalline component or mediated by a ubiquitous nondiffracting amorphous phase. Fe-HAp and Fe-OAp are not intrinsically suitable magnetic agents for drug delivery but may be useful in reactive cements that promote osteoblast proliferation.

Simple route to monodispersed silica-titania core-shell photocatalysts.

A monodispersed silica-titania core-shell photocatalyst was synthesized via a sol-gel route without the need of pH adjustment, cationic polyelectrolytes, or surfactants in a process where silica spheres were impregnated with hydrolyzed titanium tetrabutoxide, incubated at room temperature, and then condensed using an ethanol/water (1:1) solvent. Four coating cycles in a 10% v/v titania sol produced homogeneous titania shells. The quality of catalysts was assessed quantitatively using Rietveld analysis of powder X-ray diffraction patterns combined with X-ray fluorescence spectrometry. During calcination, the anatase-to-rutile transformation was delayed to 1000 degrees C, which is approximately 300 degrees C higher than usually observed. The thermal stability and surface area of titania were enhanced through the slow crystal growth of anatase. The photocatalytic activity of the core-shell photocatalysts calcined at 400-600 degrees C was found to be proportional to the thickness of titania but did not directly correlate with the surface area.