294 research outputs found
An elastic, plastic, viscous model for slow shear of a liquid foam
We suggest a scalar model for deformation and flow of an amorphous material
such as a foam or an emulsion. To describe elastic, plastic and viscous
behaviours, we use three scalar variables: elastic deformation, plastic
deformation rate and total deformation rate; and three material specific
parameters: shear modulus, yield deformation and viscosity. We obtain equations
valid for different types of deformations and flows slower than the relaxation
rate towards mechanical equilibrium. In particular, they are valid both in
transient or steady flow regimes, even at large elastic deformation. We discuss
why viscosity can be relevant even in this slow shear (often called
"quasi-static") limit. Predictions of the storage and loss moduli agree with
the experimental literature, and explain with simple arguments the non-linear
large amplitude trends
Synthesis of Polyhydroxylated Pyrano-Pyrrole Derivatives from Carbohydrate Precursors
The efficient synthesis of novel polyhydroxy‐tetrahydropyrano‐pyrroles from acetylenic carbohydrate precursors in three to four steps is described. The methodology involves, as key steps, the ring contraction of pyridazine intermediates obtained by an inverse‐demand Diels–Alder reaction and subsequent intramolecular lactonization
Interferon β-1a in relapsing multiple sclerosis: four-year extension of the European IFNβ-1a Dose-C omparison Study
Background: Multiple sclerosis (MS) is a chronic disease requiring long-term monitoring of treatment. Objective: To assess the four-year clinical efficacy of intramuscular (IM) IFNb-1a in patients with relapsing MS from the European IFNb-1a Dose-C omparison Study. Methods: Patients who completed 36 months of treatment (Part 1) of the European IFNb-1a Dose-C omparison Study were given the option to continue double-blind treatment with IFNb-1a 30 mcg or 60 mcg IM once weekly (Part 2). Analyses of 48-month data were performed on sustained disability progression, relapses, and neutralizing antibody (NA b) formation. Results: O f 608/802 subjects who completed 36 months of treatment, 493 subjects continued treatment and 446 completed 48 months of treatment and follow-up. IFNb-1a 30 mcg and 60 mcg IM once weekly were equally effective for up to 48 months. There were no significant differences between doses over 48 months on any of the clinical endpoints, including rate of disability progression, cumulative percentage of patients who progressed (48 and 43, respectively), and annual relapse rates; relapses tended to decrease over 48 months. The incidence of patients who were positive for NAbs at any time during the study was low in both treatment groups. Conclusion: C ompared with 60-mcg IM IFNb-1a once weekly, a dose of 30 mcg IM IFNb-1a once weekly maintains the same clinical efficacy over four years
Is there a role for menopausal hormone therapy in the management of postmenopausal osteoporosis?
We provide an evidence base and guidance for the use of menopausal hormone therapy (MHT) for the maintenance of skeletal health and prevention of future fractures in recently menopausal women. Despite controversy over associated side effects, which has limited its use in recent decades, the potential role for MHT soon after menopause in the management of postmenopausal osteoporosis is increasingly recognized. We present a narrative review of the benefits versus risks of using MHT in the management of postmenopausal osteoporosis. Current literature suggests robust anti-fracture efficacy of MHT in patients unselected for low BMD, regardless of concomitant use with progestogens, but with limited evidence of persisting skeletal benefits following cessation of therapy. Side effects include cardiovascular events, thromboembolic disease, stroke and breast cancer, but the benefit-risk profile differs according to the use of opposed versus unopposed oestrogens, type of oestrogen/progestogen, dose and route of delivery and, for cardiovascular events, timing of MHT use. Overall, the benefit-risk profile supports MHT treatment in women who have recently (< 10 years) become menopausal, who have menopausal symptoms and who are less than 60 years old, with a low baseline risk for adverse events. MHT should be considered as an option for the maintenance of skeletal health in women, specifically as an additional benefit in the context of treatment of menopausal symptoms, when commenced at the menopause, or shortly thereafter, in the context of a personalized benefit-risk evaluation
Online physical exercise intervention in older adults during lockdown: Can we improve the recipe?
peer reviewed[en] BACKGROUND: Recorded and live online physical exercise (PE) interventions are known to provide health benefits. However, the effects of prioritizing the number of live or recorded sessions remain unclear.
AIMS: To explore which recorded-live sessions ratio leads to the best implementation and benefits in older adults.
METHODS: Forty-six community-dwelling adults (> 60y.o.) were randomized into two groups completing a 12-week online PE intervention. Each group had a different ratio of live-recorded online sessions as follows: Live-Recorded-Live sessions (LRL; n = 22) vs. Recorded-Live-Recorded sessions (RLR; n = 24).
RESULTS: Drop-out rates did not reach significance (LRL:14% vs. RLR: 29%, p = 0.20), and adherence was similar (> 85%) between groups. Both groups reported similar levels of satisfaction (> 70%), enjoyment (> 75%), and perceived exertion (> 60%). Both groups increased physical health and functional capacities, with greater improvements in muscle power (LRL: LRL: + 35 ± 16.1% vs. RLR: + 7 ± 13.9%; p = 0.010) and endurance (LRL: + 34.7 ± 15.4 vs. RLR: + 27.0 ± 26.5, p < 0.001) in the LRL group.
DISCUSSION: Both online PE intervention modalities were adapted to the participants' capacities and led to a high level of enjoyment and retention. The greater physical improvements observed in the LRL group are likely due to the higher presence of the instructor compared to the RLR group. Indeed, participants received likely more feedback to appropriately adjust postures and movements, increasing the quality of the exercises.
CONCLUSION: When creating online PE interventions containing both recorded and live sessions, priority should be given to maximizing the number of live sessions and not the number of recorded sessions
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