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Data on pediatric inflammatory bowel disease (IBD)-associated indirect and out-of-pocket (OOP) costs are limited. We aimed to estimate indirect (lost work hours and productivity) and OOP pediatric IBD-associated costs in Canada. In a nation-wide cross-sectional analysis, caregivers of children with IBD were invited to complete a questionnaire on lost work hours and OOP costs related to IBD in the 4 weeks prior to the survey. Participants were reinvited to periodically answer the same questionnaire every 3–9 months for 2 years. Lost productivity was calculated using the Human Capital method. Costs were reported in 2018 inflation-adjusted Canadian dollars. Predictors of high cost users (top 25%) were examined using binary logistic regression. Consecutive 243 (82 incident cases) of 262 (92.7%) approached participants completed the first survey with a total of 450 surveys longitudinally completed over 2 years. The median annual indirect cost per patient was $5966 (IQR $1809–$12,676), with $5721 (IQR $1366–$11,545) for Crohn’s disease (CD) and $7007 (IQR $2428–$14,057) for ulcerative colitis (UC) (P= 0.11). The annual median per patient OOP costs were $4550 with $4550 for CD and $5038 for UC (P= 0.53). Longer travel distance to clinic was associated with higher OOP costs (odds ratio = 4.55; P< 0.0001; 95% confidence interval: 1.99–10.40). Indirect and OOP IBD-associated costs are substantial and more likely to affect families living in remote communities.

The kinetics of lambda carrageenan (λ-car) adsorption/desorption on/from anchoring layers under diffusion- and convection-controlled transport conditions were investigated. The eighth generation of poly(amidoamine) dendrimers and branched polyethyleneimine possessing different shapes and polydispersity indexes were used for anchoring layer formation. Dynamic light scattering, electrophoresis, streaming potential measurements, optical waveguide lightmode spectroscopy, and quartz crystal microbalance were applied to characterize the formation of mono- and bilayers. The unique combination of the employed techniques enabled detailed insights into the mechanism of the λ-car adsorption mainly controlled by electrostatic interactions. The results show that the macroion adsorption efficiency is strictly correlated with the value of the final zeta potentials of the anchoring layers, the transport type, and the initial bulk concentration of the macroions. The type of the macroion forming the anchoring layer had a minor impact on the kinetics of λ-car adsorption. Besides significance to basic science, the results presented in this paper can be used for the development of biocompatible and stable macroion multilayers of well-defined electrokinetic properties and structure.

We describe and demonstrate a novel experimental approach to measure broadband, amplitude- and phase-resolved scattering spectra of single nanoparticles with 10-nm spatial resolution. Nanofocusing of surface plasmon polaritons (SPPs) propagating along the shaft of a conical gold taper is used to create a spatially isolated, spectrally broad nanoscale light source at its very apex. The interference between these incident SPPs and SPPs that are backpropagating from the apex leads to the formation of an inherently phase-stable interferogram, which we detect in the far field by partially scattering SPPs off a small protrusion on the taper shaft. We show that these interferograms allow the reconstruction of both the amplitude and phase of the local optical near fields around individual nanoparticles optically coupled to the taper apex. We extract local light scattering spectra of particles and quantify line broadenings and spectral shifts induced by tip-sample coupling. Our experimental findings are supported by corresponding finite-difference time-domain and coupled dipole simulations and show that, in the limit of weak tip-sample coupling, the measurements directly probe the projected local density of optical states of the plasmonic system. The combination of a highly stable inline interferometer with the inherent optical background suppression through nanofocusing makes it a promising tool for the locally resolved study of the spectral and temporal optical response of coupled hybrid nanosystems.

The coherent exchange of optical near fields between two neighbouring dipoles plays an essential role in the optical properties, quantum dynamics and thus the function of many naturally occurring and artificial nanosystems. These interactions are challenging to quantify experimentally. They extend over only a few nanometres and depend sensitively on the detuning, dephasing and relative orientation (that is, the vectorial properties) of the coupled dipoles. Here, we introduce plasmonic nanofocusing spectroscopy to record coherent light scattering spectra with 5 nm spatial resolution from the apex of a conical gold nanotaper. The apex is excited solely by evanescent fields and coupled to plasmon resonances in a single gold nanorod. We resolve resonance energy shifts and line broadenings as a function of dipole distance and relative orientation. We demonstrate how these phenomena arise from mode couplings between different vectorial components of the interacting optical near fields, specifically from the coupling of the nanorod to both transverse and longitudinal polarizabilities of the taper apex. Light scattering spectra are acquired in the near field to map dipole–dipole interactions and extract all their vectorial components with 5-nm spatial resolution.

Sensing the scattered fields of single metallic nanostructures is a crucial step towards the applications of isolated plasmonic antennas, such as for the sensing of single molecules or nanoparticles. In the past, both near- and far-field spectroscopy methods have been applied to monitor single plasmonic resonances. So far, however, these spectral-domain techniques do not yet provide the femtosecond time resolution that is needed to probe the dynamics of plasmonic fields in the time domain. Here, we introduce a time-domain technique that combines broadband Fourier-transform spectroscopy and spatial modulation spectroscopy (FT-SMS) to quantitatively measure the extinction spectra of the isolated gold nanorods with a nominal footprint of 41×10 nm2. Using a phase-stable pulse pair for excitation, the technique is capable of rejecting off-resonant stray fields and providing absolute measurements of the extinction cross section. Our results indicate that the method is well suited for measuring the optical response of strongly coupled hybrid systems with high signal-to-noise ratio. It may form the basis for new approaches towards time-domain spectroscopy of single nanoantennas with few-cycle time resolution.

Silicon is considered as one of the promising alternatives to graphite as negative electrode material in lithium-ion batteries. The electron transfer at uncharged microstructured and planar Si was characterized using the feedback mode of scanning electrochemical microscopy (SECM) and 2,5-di-tert-butyl-1,4-dimethoxybenzene as redox mediator. Approach curves and images demonstrate that the electron transfer rate constants at pristine Si are relatively small due to the native SiO2 surface layer. In addition, the electron transfer rate constants show local variations because of the heterogeneous coverage of SiO2. The SiO2 layer is at least partially removed by mechanical contact and abrasion with the microelectrode probe. After SiO2 removal by the microelectrode or by a hydrofluoric acid dip, the electron transfer rate constants increase strongly and remain heterogeneous. Moreover, the surface of the Si electrodes is at least stable over hours after SiO2 removal. The consequences for investigating the formation of the solid electrolyte interphase (SEI) on Si are discussed.

Iron oxide nanoparticles (Fe3O4-NP) were compressed together with oleic acid (OA) in a Langmuir-Blodgett trough. Optimized dilution of the NP allowed the transfer of two-dimensional nanocomposites of Fe3O4-NP and OA to gold substrates. The characterization of the two-dimensional composite by scanning force microscopy (SFM) showed the existence of a sub-monolayer coverage with a few NP being pushed into the second layer. Polarization modulation infrared reflection absorption spectra (PM IRRAS) showed the presence of oleic acid. The nanoparticles could be removed in an external magnetic field of a permanent magnet as evidenced by SFM while the OA monolayer was left on the gold substrate as shown by PM IRRAS. Such composite layers can be used for the controlled release of specified small amount of intact NP.

Silicon is considered as one of the promising alternatives to graphite as negative electrode material in lithium-ion batteries. The electron transfer at uncharged microstructured and planar Si was characterized using the feedback mode of scanning electrochemical microscopy (SECM) and 2,5-di-tert-butyl-1,4-dimethoxybenzene as redox mediator. Approach curves and images demonstrate that the electron transfer rate constants at pristine Si are relatively small due to the native SiO2surface layer. In addition, the electron transfer rate constants show local variations because of the heterogeneous coverage of SiO2. The SiO2layer is at least partially removed by mechanical contact and abrasion with the microelectrode probe. After SiO2removal by the microelectrode or by a hydrofluoric acid dip, the electron transfer rate constants increase strongly and remain heterogeneous. Moreover, the surface of the Si electrodes is at least stable over hours after SiO2removal. The consequences for investigating the formation of the solid electrolyte interphase (SEI) on Si are discussed.

Iron oxide nanoparticles (Fe3O4-NP) were compressed together with oleic acid (OA) in a Langmuir-Blodgett trough. Optimized dilution of the NP allowed the transfer of two-dimensional nanocomposites of Fe3O4-NP and OA to gold substrates. The characterization of the two-dimensional composite by scanning force microscopy (SFM) showed the existence of a sub-monolayer coverage with a few NP being pushed into the second layer. Polarization modulation infrared reflection absorption spectra (PM IRRAS) showed the presence of oleic acid. The nanoparticles could be removed in an external magnetic field of a permanent magnet as evidenced by SFM while the OA monolayer was left on the gold substrate as shown by PM IRRAS. Such composite layers can be used for the controlled release of specified small amount of intact NP.