Association of Increased Urine Brain Derived Neurotrophic Factor with Lower Urinary Tract Symptoms in Men with Benign Prostatic Hyperplasia

Urinary brain-derived neurotrophic factor（BDNF）, an ubiquitous neurotrophin, was found to rise in patients with benign prostatic hyperplasia（BPH）. We hypothesized that the urinary level of BDNF could be a potential biomarker for lower urinary tract symptoms（LUTS） in patients with BPH. Totally, 76 patients with BPH-caused LUTS and 32 male control subjects without BPH were enrolled. International Prostate Symptom Score（IPSS） was applied to assess the symptom severity of LUTS. Urodynamic tests were performed for the diagnosis of underlying detrusor overactivity（DO） in the patients with BPH. Urine samples were collected from all subjects. Urinary BDNF levels were measured using enzyme-linked immunosorbent assays and normalized by urinary creatinine（Cr） levels. Seventy-six BPH patients were divided into moderate LUTS group（n=51, 720） according to the IPSS. Of the 76 BPH patients, DO was present in 34（44.7%） according to the urodynamic test. The urinary BDNF/Cr levels were significantly higher in BPH patients with moderate LUTS（8.29±3.635, P〈0.0001） and severe LUTS（11.8±6.44, P〈0.0001） than normal controls（1.71±0.555）. Patients with severe LUTS tended to have higher urinary BDNF/Cr levels than patients with moderate LUTS（11.8±6.44 vs. 8.29±3.635, P=0.000）. The conditions of BPH with LUTS correlated with elevated urinary BDNF levels, and urinary BDNF levels were even higher in BPH-DO patients. The results of this study have provided evidence to suggest that urinary BDNF level test could evaluate the severity of LUTS in BPH patients, and BDNF level can be used as a biomarker

Numerical study on dynamic properties of rubberised concrete with different rubber contents

As a green environmentally-friendly material,rubberised concrete(Ru C),which has the characteristics of low elastic modulus,large deformation capacity,high damping,good energy dissipation and good crack resistance,has attracted extensive attention and research in the civil engineering discipline.However,most of existing studies are based on experimental tests on Ru C material properties,and there has been no numerical study based on meso-scale modelling of Ru C yet.To more comprehensively investigate the Ru C dynamic material properties without conducting intensive experimental tests,this study developed a high-fidelity meso-scale model considering coarse and fine aggregates and rubber crumbs to numerically investigate the mechanical properties of rubberised concrete under different strain rates.The meso-scale model was verified against both quasi-static compressive testing data and Split Hopkinson Pressure Bar(SHPB)dynamic testing data.Using the verified numerical model,the dynamic properties of rubberised concrete with various rubber content(0%-30%)under different strain rates were studied.The numerical results show that the developed meso-scale model can use to predict the static and dynamic properties of rubberised concrete with high accuracy.The dynamic compressive strength of the rubberised concrete increases with the increment of the strain rate,and the strain rate sensitivity increases with the rubber content ranging from 0 to 30%.Based on intensive numerical simulation data,empirical DIFs is used as a function of strain rate and rubber content to predict the dynamic strength of rubberised concrete.

Experimental investigation of rigid confinement effects of radial strain on dynamic mechanical properties and failure modes of concrete

In this study,to confirm the effect of confining pressure on dynamic mechanical behavior and failure modes of concrete,a split Hopkinson pressure bar dynamic loading device was utilized to perform dynamic compressive experiments under confined and unconfined conditions.The confining pressure was achieved by applying a lateral metal sleeve on the testing specimen which was loaded in the axial direction.The experimental results prove that dynamic peak axial stress,dynamic peak lateral stress,and peak axial strain of concrete are strongly sensitive to the strain rate under confined conditions.Moreover,the failure patterns are significantly affected by the stress-loading rate and confining pressure.Concrete shows stronger strain rate effects under an unconfined condition than that under a confined condition.More cracks are created in concrete subjected to uniaxial dynamic compression at a higher strain rate,which can be explained by a thermal-activated mechanism.By contrast,crack generation is prevented by confinement.Fitting formulas of the dynamic peak stress and dynamic peak axial strain are established by considering strain rate effects(50–250 s-1)as well as the dynamic confining increase factor(DIFc).