2,157 research outputs found
The impact of rheumatoid arthritis on foot function in the early stages of disease: a clinical case series
BACKGROUND
Foot involvement occurs early in rheumatoid arthritis but the extent to which this impacts on the structure and function leading to impairment and foot related disability is unknown. The purpose of this study was to compare clinical disease activity, impairment, disability, and foot function in normal and early rheumatoid arthritis (RA) feet using standardised clinical measures and 3D gait analysis.
METHODS
Twelve RA patients with disease duration â¤2 years and 12 able-bodied adults matched for age and sex underwent 3D gait analysis to measure foot function. Disease impact was measured using the Leeds Foot impact Scale (LFIS) along with standard clinical measures of disease activity, pain and foot deformity. For this small sample, the mean differences between the groups and associated confidence intervals were calculated using the t distribution
RESULTS
Moderate-to-high foot impairment and related disability were detected amongst the RA patients. In comparison with age- and sex-matched controls, the patients with early RA walked slower (1.05 m/s Vs 1.30 m/s) and had a longer double-support phase (19.3% Vs 15.8%). In terminal stance, the heel rise angle was reduced in the patients in comparison with normal (-78.9° Vs -85.7°). Medial arch height was lower and peak eversion in stance greater in the RA patients. The peak ankle plantarflexion power profile was lower in the patients in comparison with the controls (3.4 W/kg Vs 4.6 W/kg). Pressure analysis indicated that the RA patients had a reduced lesser toe contact area (7.6 cm2 Vs 8.1 cm2), elevated peak forefoot pressure (672 kPa Vs 553 kPa) and a larger mid-foot contact area (24.6 cm2 Vs 19.4 cm2).
CONCLUSION
Analysis detected small but clinically important changes in foot function in a small cohort of RA patients with disease duration <2 years. These were accompanied by active joint disease and impairment and disability
Exploratory study to identify mechanical factors that may contribute to toe dactylitis in patients with psoriatic arthritis
Syntheses and Properties of Two-Dimensional, Dicationic Nonlinear Optical Chromophores Based on Pyrazinyl Cores
Six new dicationic 2D nonlinear optical (NLO) chromophores with pyrazinyl-pyridinium electron acceptors have been synthesized by nucleophilic substitutions of 2,6-dichloropyrazine with pyridyl derivatives. These compounds have been characterized as their PF_6^â salts by using various techniques including electronic absorption spectroscopy and cyclic voltammetry. Large red shifts in the intense, Ď â Ď* intramolecular charge-transfer (ICT) transitions on replacing âOMe with âNme_2 substituents arise from the stronger Ď-electron donor ability of the latter. Each compound shows a number of redox processes which are largely irreversible. Single crystal X-ray structures have been determined for five salts, including two nitrates, all of which adopt centrosymmetric packing arrangements. Molecular first hyperpolarizabilities β have been determined by using femtosecond hyper-Rayleigh scattering at 880 and 800 nm, and depolarization studies show that the NLO responses of the symmetric species are strongly 2D, with dominant âoff-diagonalâ β_(zyy) components. Stark (electroabsorption) spectroscopic measurements on the ICT bands afford estimated static first hyperpolarizabilities β_0. The directly and indirectly derived β values are large, and the Stark-derived β_0 response for one of the new salts is several times greater than that determined for (E)-4â˛-(dimethylamino)-N-methyl-4-stilbazolium hexafluorophosphate. These Stark spectroscopic studies also permit quantitative comparisons with related 2D, binuclear RuII ammine complex salts
Empathy and Emulation: Life Satisfaction and the Urban Geography of Comparison Groups
Departures from self-centred, consumption-oriented decision making are increasingly common in economic theory and are well motivated by a wide range of behavioural data from experiments, surveys, and econometric inference. A number of studies have shown large negative externalities in individual subjective well-being due to neighbours' incomes. These reflect the role of nearby households as comparison groups acting in individuals' reference-dependent preferences over income or consumption. At the same time, there are many reasons to expect positive spillovers from having prosperous neighbours. We combine high-resolution geographic data from three Canada-wide social surveys and the 2001 census to disentangle the spatial pattern of reference groups in urban areas and to identify channels of positive and negative spillovers on life satisfaction. We find evidence of significant effects of others' income at different scales and are able to reject a number of alternative explanations for the findings.
Measuring and Understanding Subjective Well-Being
Increasing attention is being paid in academic, policy, and public arenas to subjective measures of well-being. This promising trend represents a shift towards measuring positive outcomes in psychology and greater realism in the study of economic behaviour. After a general review of past and potential uses for subjective well-being data, and a discussion of why some economists have previously been sceptical of SWB data, we present global and Canadian examples from our own research to illustrate what can be learned. Differences in subjective well-being will be shown to be large and sustained across individuals, communities, provinces and nations. Although the patterns of subjective well-being are very different across Canada than across the world, we show that in both cases the differences can be fairly well accounted for by the same set of life circumstances. Our examples of policy-relevant research findings include new accountings of the differences in individual-level SWB assessments around the world and across Canada. These highlight the importance of social factors whose role has otherwise been hard to quantify in income-equivalent terms.
The dynamics of response as measured by multiple composite outcome tools in the TIght COntrol of inflammation in early Psoriatic Arthritis (TICOPA) trial
Background: We aimed to evaluate the dynamics of treatment response with different composite measures in the TIght COntrol of inflammation in early Psoriatic Arthritis (TICOPA) trial. Methods: Participants with early disease-modifying antirheumatic drug-naĂŻve psoriatic arthritis (PsA) were randomised 1:1 to either tight control (TC; 4 weekly review with therapy escalation if criteria not met) or standard care (SC; 12 weekly review). We calculated modified versions of the Psoriatic ArthritiS Disease Activity Score (PASDAS), Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) Composite scorE (GRACE) and Composite Psoriatic Disease Activity Index (CPDAI) at baseline and 12 weekly to 48 weeks by blinded assessor. For missing data, we used the last observation carried forward. Comparison between groups was made by analysis of covariance and comparison of area under the curve (AUC). Results: 206 people were randomised to TC (n=101) or SC (n=105). Significant differences between treatment groups were seen (p<0.0001 for all composite measures). AUC analysis demonstrated a significant difference between groups for the PASDAS but not GRACE and CPDAI. For participants with oligoarthritis, a significant difference between groups was seen for each measure, although the significance levels were greatly diminished (PASDAS, p=0.04; GRACE p=0.01; CPDAI p=0.04). For oligoarthritis using AUC analysis, none of the measures could distinguish between groups. Conclusions: Composite measures of disease activity were able to distinguish between TICOPA treatment arms, although differences were diminished for those with oligoarthritis. Further data are needed to inform the preferred composite measure for use as the primary outcome in PsA trials
The dynamics of response as measured by multiple composite outcome tools in the TIght COntrol of inflammation in early Psoriatic Arthritis (TICOPA) trial
Background: We aimed to evaluate the dynamics of treatment response with different composite measures in the TIght COntrol of inflammation in early Psoriatic Arthritis (TICOPA) trial. Methods: Participants with early disease-modifying antirheumatic drug-naĂŻve psoriatic arthritis (PsA) were randomised 1:1 to either tight control (TC; 4 weekly review with therapy escalation if criteria not met) or standard care (SC; 12 weekly review). We calculated modified versions of the Psoriatic ArthritiS Disease Activity Score (PASDAS), Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) Composite scorE (GRACE) and Composite Psoriatic Disease Activity Index (CPDAI) at baseline and 12 weekly to 48 weeks by blinded assessor. For missing data, we used the last observation carried forward. Comparison between groups was made by analysis of covariance and comparison of area under the curve (AUC). Results: 206 people were randomised to TC (n=101) or SC (n=105). Significant differences between treatment groups were seen (p<0.0001 for all composite measures). AUC analysis demonstrated a significant difference between groups for the PASDAS but not GRACE and CPDAI. For participants with oligoarthritis, a significant difference between groups was seen for each measure, although the significance levels were greatly diminished (PASDAS, p=0.04; GRACE p=0.01; CPDAI p=0.04). For oligoarthritis using AUC analysis, none of the measures could distinguish between groups. Conclusions: Composite measures of disease activity were able to distinguish between TICOPA treatment arms, although differences were diminished for those with oligoarthritis. Further data are needed to inform the preferred composite measure for use as the primary outcome in PsA trials
Quadratic and Cubic Nonlinear Optical Properties of Salts of Diquat-Based Chromophores with Diphenylamino Substituents
A series of chromophoric salts has been prepared in which 4-(diphenylamino)phenyl (Dpap) electron donor groups are connected to electron-accepting diquaternized 2,2â˛-bipyridyl (diquat) units. The main aim is to combine large quadratic and cubic nonlinear optical (NLO) effects in potentially redox-switchable molecules with 2D structures. The chromophores have been characterized as their PF_6^â salts by using various techniques including electronic absorption spectroscopy and cyclic voltammetry. The visible absorption spectra are dominated by intense Ď â Ď* intramolecular charge-transfer (ICT) bands, and all of the compounds show two reversible or quasireversible diquat-based reductions and partially reversible Dpap oxidations. Single crystal X-ray structures have been obtained for one salt and for the precursor compound (E)-4-(diphenylamino)cinnamaldehyde, both of which adopt centrosymmetric space groups. First hyperpolarizabilities β have been measured by using hyper-Rayleigh scattering (HRS) with a 800 nm laser, and Stark (electroabsorption) spectroscopy of the ICT bands affords estimated static first hyperpolarizabilities β_0. The directly and indirectly derived β values are large and generally increased substantially for the bis-Dpap derivatives when compared with their monosubstituted analogues. Polarized HRS studies show that the NLO responses of the disubstituted species are dominated by âoff-diagonalâ β_(zyy) components. Lengthening the diquaternizing alkyl unit lowers the electron-acceptor strength and therefore increases the ICT energies and decreases the E_(1/2) values for diquat reduction. However, compensating increases in the ICT intensity prevent significant decreases in the Stark-based β_0 responses. Cubic NLO properties have been measured by using the Z-scan technique over a wavelength range of 520â1600 nm, revealing relatively high two-photon absorption cross-sections of up to 730 GM at 620 nm for one of the disubstituted chromophores
Syntheses and Properties of Salts of Chromophores with Ferrocenyl Electron Donor Groups and Quaternary Nitrogen Acceptors
A series of five new dipolar cations has been synthesized with ferrocenyl (Fc) electron donor groups connected to N-arylpyridinium, N-methylquinolinium, N-methylbenzothiazolium, or N-methylacridinium acceptors. Together with their known N-methylpyridinium analogue, these chromophores have been characterized as their PF_6^â salts by using various techniques including electronic absorption spectroscopy and cyclic voltammetry. Nine single-crystal X-ray structures have been determined, including two polymorphs of one salt obtained from a single crystallization experiment, and two of these are polar materials. A highly favorable degree of dipolar alignment for bulk NLO effects is observed in one case. Molecular quadratic nonlinear optical (NLO) responses have been determined by using femtosecond hyper-Rayleigh scattering (HRS) at 1300 nm and also via Stark (electroabsorption) spectroscopic studies on the intense Ď â Ď^* intraligand and d â Ď^* metal-to-ligand charge-transfer bands. A broad correlation between the electron acceptor strength and the HRS-derived first hyperpolarizabilities β and the static first hyperpolarizabilities β0 estimated from the Stark data is evident. This is the first time that meaningful (albeit indirectly determined) β_0 data have been reported for Fc compounds, allowing quantitative comparisons with the chromophore in the technologically important material (E)-4â˛-(dimethylamino)-N-methyl-4-stilbazolium (DAS) tosylate. The observed β_0 values are in several cases similar to that of [DAS]PF_6, and possibly even larger in one instance
International evidence on the social context of well-being
This paper uses the first three waves of the Gallup World Poll to investigate differences across countries, cultures and regions in the factors linked to life satisfaction, paying special attention to the social context. Our principal findings are: First, using the larger pooled sample, we find that answers to the satisfaction with life and Cantril ladder questions provide consistent views of what constitutes a good life, with an average of the two measures providing a clearer picture than either measure on its own. Second, we find strong evidence for the importance of both income and social context variables in explaining within-country and international differences in well-being. For most specifications tested, the combined effects of a few measures of the social and institutional context are as large as those of income in explaining both international and intra-national differences in life satisfaction. Third, the very significant influences of both income and social factors permit the calculation of compensating differentials for social factors. We find very large income-equivalent values for key measures of the social context. Fourth, the international similarity of the estimated equations suggests that the large international differences in average life evaluations are not due to different approaches to the meaning of a good life, but to differing social, institutional, and economic life circumstances
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