Auxetic Interval Determination and Experimental Validation for a Three-Dimensional Periodic Framework

Auxetic behavior refers to lateral widening upon stretching or, in reverse, lateral shrinking upon compression. When an initially auxetic structure is actuated by compression or extension, it will not necessarily remain auxetic for larger deformations. In this paper, we investigate the auxetic range in the deformation of a periodic framework with one degree of freedom. We use geometric criteria to identify the interval where the deformation is auxetic and validate these theoretical findings with compression experiments on sample structures with (Formula presented.) unit cells

Auxetic interval determination and experimental validation for a three-dimensional periodic framework

Auxetic behavior refers to lateral widening upon stretching or, in reverse, lateral shrinking upon compression. When an initially auxetic structure is actuated by compression or extension, it will not necessarily remain auxetic for larger deformations. In this paper, we investigate the auxetic range in the deformation of a periodic framework with one degree of freedom. We use geometric criteria to identify the interval where the deformation is auxetic and validate these theoretical findings with compression experiments on sample structures with (Formula presented.) unit cells.Precision and Microsystems EngineeringMechatronic Systems Desig

Surgery versus Physiotherapy for Stress Urinary Incontinence

<p>BackgroundPhysiotherapy involving pelvic-floor muscle training is advocated as first-line treatment for stress urinary incontinence; midurethral-sling surgery is generally recommended when physiotherapy is unsuccessful. Data are lacking from randomized trials comparing these two options as initial therapy.</p><p>MethodsWe performed a multicenter, randomized trial to compare physiotherapy and midurethral-sling surgery in women with stress urinary incontinence. Crossover between groups was allowed. The primary outcome was subjective improvement, measured by means of the Patient Global Impression of Improvement at 12 months.</p><p>ResultsWe randomly assigned 230 women to the surgery group and 230 women to the physiotherapy group. A total of 49.0% of women in the physiotherapy group and 11.2% of women in the surgery group crossed over to the alternative treatment. In an intention-to-treat analysis, subjective improvement was reported by 90.8% of women in the surgery group and 64.4% of women in the physiotherapy group (absolute difference, 26.4 percentage points; 95% confidence interval [CI], 18.1 to 34.5). The rates of subjective cure were 85.2% in the surgery group and 53.4% in the physiotherapy group (absolute difference, 31.8 percentage points; 95% CI, 22.6 to 40.3); rates of objective cure were 76.5% and 58.8%, respectively (absolute difference, 17.8 percentage points; 95% CI, 7.9 to 27.3). A post hoc per-protocol analysis showed that women who crossed over to the surgery group had outcomes similar to those of women initially assigned to surgery and that both these groups had outcomes superior to those of women who did not cross over to surgery.</p><p>ConclusionsFor women with stress urinary incontinence, initial midurethral-sling surgery, as compared with initial physiotherapy, results in higher rates of subjective improvement and subjective and objective cure at 1 year.</p>