Enhancing validity, reliability and participation in self-reported health outcome measurement for children and young people: a systematic review of recall period, response scale format, and administration modality.

INTRODUCTION: Self-report is the gold standard for measuring children's health-related outcomes. Design of such measures is complex and challenging. This review aims to systematically appraise the evidence on recall period, response scale format, mode of administration and approaches needed to enable children and young people < 19 years to participate in valid and reliable self-reporting of their health outcomes. METHOD: PsycInfo, Medline, CINAHL and Embase were searched from 1 January 1990 to 15 March 2020, and citation searching undertaken in Scopus. Articles were included if they were primary research or case reports of ≥ 3 participants reporting the following: recall period, response scale selection, administration modality. Quality was assessed using QualSyst, and results synthesised narratively. This review was conducted and reported according to PRISMA guidelines. RESULTS: 81 of 13,215 retrieved articles met the inclusion criteria. Children < 5 years old cannot validly and reliably self-report health outcomes. Face scales demonstrate better psychometric properties than visual analogue or Likert scales. Computerised and paper scales generally show equivalent construct validity. Children prefer computerised measures. Children ≤ 7 years old think dichotomously so need two response options. Those > 8 years old can reliably use a 3-point scale. CONCLUSION: The results of this review have both clinical and research implications. They can be used to inform appropriate choice of PROM for use with CYP in the clinical setting. We also give eight recommendations for future development of self-reported outcome measures for children and young people.

Nonlinear Ultrafast Spin Scattering in the Skyrmion Phase of Cu_{2}OSeO_{3}.

Ultrafast x-ray scattering studies of the topological Skyrmion phase in Cu_{2}OSeO_{3} show the dynamics to be strongly dependent on the excitation energy and fluence. At high photon energies, where the electron-spin scattering cross section is relatively high, the excitation of the topological Skyrmion phase shows a nonlinear dependence on the excitation fluence, in contrast to the excitation of the conical phase which is linearly dependent on the excitation fluence. The excitation of the Skyrmion order parameter is nonlinear in the magnetic excitation resulting from scattering during electron-hole recombination, indicating different dominant scattering processes in the conical and Skyrmion phases.

Selective interlayer ferromagnetic coupling between the Cu spins in YBa2Cu3O7-x grown on top of La0.7Ca0.3MnO3.

Studies to date on ferromagnet/d-wave superconductor heterostructures focus mainly on the effects at or near the interfaces while the response of bulk properties to heterostructuring is overlooked. Here we use resonant soft x-ray scattering spectroscopy to reveal a novel c-axis ferromagnetic coupling between the in-plane Cu spins in YBa2Cu3O7-x (YBCO) superconductor when it is grown on top of ferromagnetic La0.7Ca0.3MnO3 (LCMO) manganite layer. This coupling, present in both normal and superconducting states of YBCO, is sensitive to the interfacial termination such that it is only observed in bilayers with MnO2 but not with La0.7Ca0.3O interfacial termination. Such contrasting behaviors, we propose, are due to distinct energetic of CuO chain and CuO2 plane at the La0.7Ca0.3O and MnO2 terminated interfaces respectively, therefore influencing the transfer of spin-polarized electrons from manganite to cuprate differently. Our findings suggest that the superconducting/ferromagnetic bilayers with proper interfacial engineering can be good candidates for searching the theorized Fulde-Ferrel-Larkin-Ovchinnikov (FFLO) state in cuprates and studying the competing quantum orders in highly correlated electron systems.

Coupled Skyrmion sublattices in Cu(2)OSeO(3).

We report the observation of a Skyrmion lattice in the chiral multiferroic insulator Cu2OSeO3 using Cu L3-edge resonant soft x-ray diffraction. We observe the unexpected existence of two distinct Skyrmion sublattices that arise from inequivalent Cu sites with chemically identical coordination numbers but different magnetically active orbitals. The Skyrmion sublattices are rotated with respect to each other, implying a long wavelength modulation of the lattice. The modulation vector is controlled with an applied magnetic field, associating this moirélike phase with a continuous phase transition. Our findings will open up a new class of science involving manipulation of quantum topological states.

Glass-like recovery of antiferromagnetic spin ordering in a photo-excited manganite Pr0.7Ca0.3MnO3.

Electronic orderings of charges, orbitals and spins are observed in many strongly correlated electron materials, and revealing their dynamics is a critical step toward undertsanding the underlying physics of important emergent phenomena. Here we use time-resolved resonant soft x-ray scattering spectroscopy to probe the dynamics of antiferromagnetic spin ordering in the manganite Pr0.7Ca0.3MnO3 following ultrafast photo-exitation. Our studies reveal a glass-like recovery of the spin ordering and a crossover in the dimensionality of the restoring interaction from quasi-1D at low pump fluence to 3D at high pump fluence. This behavior arises from the metastable state created by photo-excitation, a state characterized by spin disordered metallic droplets within the larger charge- and spin-ordered insulating domains. Comparison with time-resolved resistivity measurements suggests that the collapse of spin ordering is correlated with the insulator-to-metal transition, but the recovery of the insulating phase does not depend on the re-establishment of the spin ordering.

The alteration of lipid bilayer dynamics by phloretin and 6-ketocholestanol.

Lipid bilayer properties are quantified with a variety of arbitrary selected parameters such as molecular packing and dynamics, electrostatic potentials or permeability. In the paper we determined the effect of phloretin and 6-ketocholestanol (dipole potential modifying agents) on the membrane hydration and efficiency of the trans-membrane water flow. The dynamics of water molecules within the lipid bilayer interface was evaluated using solvent relaxation method, whereas the osmotically induced trans-membrane water flux was estimated with the stopped-flow method using the liposome shrinkage kinetics. The presence of phloretin or 6-ketocholestanol resulted in a change of both, the interfacial hydration level and osmotically driven water fluxes. Specifically, the presence of 6-ketocholestanol reduced the amount and mobility of water in the membrane interface. It also slows the osmotically induced water flow. The interfacial hydration change caused by phloretin was much smaller and the effect on osmotically induced water flow was opposite to that of 6-ketocholestanol.

Real-time manifestation of strongly coupled spin and charge order parameters in stripe-ordered La(1.75)Sr(0.25)NiO(4) nickelate crystals using time-resolved resonant x-ray diffraction.

We investigate the order parameter dynamics of the stripe-ordered nickelate, La(1.75)Sr(0.25)NiO(4), using time-resolved resonant x-ray diffraction. In spite of distinct spin and charge energy scales, the two order parameters' amplitude dynamics are found to be linked together due to strong coupling. Additionally, the vector nature of the spin sector introduces a longer reorientation time scale which is absent in the charge sector. These findings demonstrate that the correlation linking the symmetry-broken states does not unbind during the nonequilibrium process, and the time scales are not necessarily associated with the characteristic energy scales of individual degrees of freedom.

Phase fluctuations and the absence of topological defects in a photo-excited charge-ordered nickelate.

The dynamics of an order parameter's amplitude and phase determines the collective behaviour of novel states emerging in complex materials. Time- and momentum-resolved pump-probe spectroscopy, by virtue of measuring material properties at atomic and electronic time scales out of equilibrium, can decouple entangled degrees of freedom by visualizing their corresponding dynamics in the time domain. Here we combine time-resolved femotosecond optical and resonant X-ray diffraction measurements on charge ordered La(1.75)Sr(0.25)NiO(4) to reveal unforeseen photoinduced phase fluctuations of the charge order parameter. Such fluctuations preserve long-range order without creating topological defects, distinct from thermal phase fluctuations near the critical temperature in equilibrium. Importantly, relaxation of the phase fluctuations is found to be an order of magnitude slower than that of the order parameter's amplitude fluctuations, and thus limits charge order recovery. This new aspect of phase fluctuations provides a more holistic view of the phase's importance in ordering phenomena of quantum matter.

Ferromagnetic enhancement of CE-type spin ordering in (Pr,Ca)MnO3.

We present resonant soft x-ray scattering results from small bandwidth manganites (Pr,Ca)MnO(3), which show that the CE-type spin ordering (SO) at the phase boundary is stabilized only below the canted antiferromagnetic transition temperature and enhanced by ferromagnetism in the macroscopically insulating state (FM-I). Our results reveal the fragility of the CE-type ordering that underpins the colossal magnetoresistance effect in this system, as well as an unexpected cooperative interplay between FM-I and CE-type SO which is in contrast to the competitive interplay between the ferromagnetic metallic state and CE-type ordering.

Improved method to evaluate the ability of compounds to destabilize the cellular plasma membrane.

In the paper, we present an improved method for evaluation of a compound ability to destabilize erythrocyte plasma membrane. The proposed method is based on the continuous monitoring of the light scattered by erythrocytes exposed to osmotic pressure differences. The kinetics of hemolysis depends on the plasma membrane mechanics and the extent of the osmotic stress. Generally, the osmotic pressure difference of approximately 150 mOsm is taken for measurements, as a result of the equal volume mixing with the physiological salt solutions. In this approach the hemolytic process completion is not established which may result in poor quality and reproducibility of the experimental data. In consequence, inaccurate parameters of the kinetic are determined due to the low quality fitting to the, widely used, single exponential model. In the paper we propose a new experimental protocol allowing to determine the extended set of parameters for kinetics of hemolysis. Namely, the method of the minimal osmotic pressure difference determination is proposed which ensures the completeness of the hemolytic process. This step allows improving the quality and exactness of the calculated parameters. The developed methodology was tested on two qualitatively different, biologically relevant, experiments; evaluation of the peptide effect on the plasma membrane properties and differentiating between human and rabbit erythrocytes.

Observation of ferromagnetic resonance in SrRuO3 by the time-resolved magneto-optical Kerr effect.

We report the observation of ferromagnetic resonance (FMR) in SrRuO3 using the time-resolved magneto-optical Kerr effect. The FMR oscillations in the time-domain appear in response to a sudden, optically induced change in the direction of easy-axis anisotropy. The high FMR frequency, 250 GHz, and large Gilbert damping parameter, alpha approximately 1, are consistent with strong spin-orbit coupling. We find that the parameters associated with the magnetization dynamics, including alpha, have a nonmonotonic temperature dependence, suggestive of a link to the anomalous Hall effect.

Pruritus measurement and treatment.

Pruritus measurement is problematic, because of its subjective nature and poor localization. Ratio scales enhance the usefulness of the visual analogue scale (VAS) by reducing variation; other scales such as the generalized labelled magnitude scale may also be useful. Pruritus neuroanatomy includes peripheral receptors, peripheral and central nerves, ascending and descending spinal pathways, and several brain regions. Pruritus receptors include Merkel discs and free nerve endings, and itch receptors have fast or slow adaptation. In this review, we discuss the pathophysiology of pruritus in atopic dermatitis, psoriasis and scabies. Pruritus treatment is reviewed for topical agents and antihistamines. Future research directions are suggested.

Many common drugs in dermatology are light, temperature, or moisture-sensitive.

Photosensitivity is defined as responsiveness to light exposure. For many common dermatologic drugs, proper storage conditions are essential for maintaining drug activity. Degradation and loss of activity can occur with exposure to light, temperature, and/ or moisture. For example, ketoconazole degrades after 24 hours of light exposure. In this article storage guidelines for common dermatology drugs are provided. We suspect that drug degradation is common due to improper storage and that improved patient instruction regarding storage will reduce degradation and alleviate some of the danger associated with improper storage and usage patterns.

Molecular interpretation of fluorescence solvent relaxation of Patman and 2H NMR experiments in phosphatidylcholine bilayers.

The analysis of time-dependent fluorescence shifts of the bilayer probe 6-hexadecanoyl-2-(((2-(trimethylammonium)ethyl)methyl)amino)naphthalene chloride (Patman) offers valuable information on the hydration and dynamics of phospholipid headgroups. Quenching studies on vesicles composed of four phosphatidylcholines with different hydrocarbon chains (18:1c9/18:1c9, DOPC; 16:0/18:1c9, POPC; 18:1c9/16:0, OPPC; 18:1c6/18:1c6, PCDelta6) show that the chromophore of Patman is defined located at the level of the sn-1 ester-group in the phospholipid, which is invariant to the hydrocarbon chain. The so-called solvent relaxation (SR) approach as well as solid-state 2H NMR reveals that DOPC and PCDelta6 are more hydrated than POPC and OPPC. A strong dependence of SR kinetics on the position of double bond in the investigated fatty acid chains was observed. Apparently, the closer the double bond is located to the hydrated sn-1 ester-group, the more mobile this group becomes. This work demonstrates that the SR approach can report mobility changes within phospholipid bilayers with a remarkable molecular resolution.

Abrupt transition in quasiparticle dynamics at optimal doping in a cuprate superconductor system.

We report time-resolved measurements of the photoinduced change in reflectivity, DeltaR, in the Bi2Sr2Ca(1-y)Dy(y)Cu2O8+delta (BSCCO) system of cuprate superconductors as a function of hole concentration. We find that the kinetics of quasiparticle decay and the sign of DeltaR both change abruptly where the superconducting transition temperature T(c) is maximal. These coincident changes suggest that a sharp transition in quasiparticle dynamics takes place precisely at optimal doping in the BSCCO system.

ESR and monolayer study of the localization of coenzyme Q10 in artificial membranes.

The data obtained from the ESR experiments show a complex, depth dependent effect of CoQ10 on the lipid molecules mobility in the bilayer. These effects depend both on its concentration and the temperature. CoQ10 disturbs not only the hydrophobic core of the membrane but also the region close to the hydrophilic headgroups of phospholipids. Both these effects could be explained by the fact that the high hydrophobicity of CoQ10 causes the molecules to position itself in the interior of the bilayer, but at the same time its water seeking headgroup is located close to the region of the polar headgrops of membrane lipids. The presence of CoQ10 in the hydrophobic core has further implications on the properties of membrane intrinsic domain. Results of monolayer experiments indicate that CoQ10 may form aggregates when mixed with PC molecules in the lipid hydrocarbon chain-length dependent manner. CoQ10 is not fully miscible with DMPC or DPPC but it is well miscible with the long-chain DSPC molecules. Our suggestion is that CoQ10 when present in long-chain phospholipid bilayer, interacts with saturated fatty acyl-chains and adapt the structure which allows such interactions: either parallel to the saturated acyl chains or "pseudo-ring" conformation resembling sterol structure.

Combined effect of surface electrostatic charge and poly(ethyl glycol) on the association of liposomes with colon carcinoma cells.

Particulate drug formulations are considered to be a means that may improve the pharmacokinetics and biodistribution of active compounds. By using them, drug distribution is determined solely by the properties of the carrier. The surface properties of such supramolecular aggregates determine how they will interact with various biological structures. Among others, surface electrostatic charge and surface grafted polymers are considered to be among the major factors affecting its interaction with proteins and cells. In this article, we present experimental evidence that properly selected surface electrostatic charge and grafted polymers can alter the association of liposomes with colon cancer cells. The dependence of the adsorption of liposomes onto the cell surface on the quantity and length of surface grafted polymers for a certain surface charge density exhibits a distinct maximum. For example, when liposomes were formed with 20 mol% of DOTAP, PE-PEG350 increased liposome adsorption by up to 6 mol%. This adsorption maximum depends on both polymer length and charge type. Results presented in this article show that the interaction of liposomes with colon cancer cells can be tuned by a proper combination of liposome surface electrostatics and surface grafted polymers.

Hereditary spherocytosis: identification of several HS families with ankyrin and band 3 deficiency in a population of southwestern Poland.

Red blood cells of 17 patients out of seven families diagnosed with HS from the southwest of Poland were studied. In six families a deficiency of ankyrin was detected, and in one family a band 3 (anion-exchanger protein) deficiency was detected. Patients from six families with the ankyrin deficiency had a 19-51% decrease in ankyrin 2.1, while the family with the band 3 deficiency showed a 33% decrease in this protein content. All changes were statistically significant, as analysed by the Student t test (P<0.05). Analysis of haemolysis kinetics gives a reliable indication of altered osmotic properties of the spherocytic cells.

The effect of steric constraints on the adsorption of phenyltin onto the dipalmitoylphosphatidylcholine bilayer.

In this paper, we present studies concerning phenyltin adsorption onto the dipalmitoylphosphatidylcholine bilayer. Phenyltin compounds are known to be biologically active, and their molecular geometry makes it possible to study the effect of steric constraints on their ability to penetrate the model lipid membrane. Using a fluorescence probe as a reporter of the amount of adsorbed compound, we evaluated their affinity to the membrane as a function of the membrane state. The amount of the adsorbed compound was found to depend on the adsorbing molecule's geometry and lipid bilayer organization. The fluorescence measurements were supported by the density functional theory (DFT) method of quantum mechanical computations. The penetrant location was correlated with the possible relative positions of its polar and hydrophobic moieties to determine if it could adopt structural requirements of the local membrane environment. Molecules were deformed by a model force, mimicking interactions within the membrane interfacial region. Computations show that the diphenyltin molecule can be deformed to such an extent that it can adopt an amphiphilic conformation. Triphenyltin is different, as its bending requires more energy. Born repulsion energies from hydrophobic fluid into water for phenyltins were also computed in an isodensity-polarized continua model of DFT computation. Our results indicate that the phenyltin compounds incorporate into the interface of the lipid membrane, although diphenyltin integrates more deeply than triphenyltin, which locates on the double layer's surface, and this is due to the fact that the main role is played by steric and not electrostatic interactions.

Surface charge and the association of liposomes with colon carcinoma cells.

Interaction between the plasma membrane and aggregate lipid surface determines how efficiently the encapsulated drug will be delivered into the cell. Electrostatic interactions are one of the main forces affecting liposome and aggregate association with the charged cell surface. In this study, the effect of surface charge on the association of liposomes with human colon CX-1.1 cancer cells was studied. When phosphatidylserine was incorporated into a lipid bilayer, the amount of liposomes associated with cells tended to increase along with the amount of negatively charged lipid present in the liposomal lipid bilayer. When the cationic lipid dioleoyl-1,2-diacyl-3-trimethylammonium-propane (DOTAP) was included into the liposome formula, their uptake by the cells was also increased. Maximum binding occurred when the amount of positively charged lipids in liposomes was about 10 mol% of lipids.