Neuroprotective effects of meloxicam on transient brain ischemia in rats:the two faces of anti-inflammatory treatments

The inflammato ry response plays an important role in neuroprotection and regeneration after ischemic insult.The use of non-ste roidal anti-inflammatory drugs has been a matter of debate as to whether they have beneficial or detrimental effects.In this context,the effects of the anti-inflammatory agent meloxicam have been scarcely documented after stro ke,but its ability to inhibit both cyclooxygenase isoforms(1 and 2) could be a promising strategy to modulate postischemic inflammation.This study analyzed the effect of meloxicam in a transient focal cerebral ischemia model in rats,measuring its neuroprotective effect after 48 hours and 7 days of reperfusion and the effects of the treatment on the glial scar and regenerative events such as the generation of new progenitors in the subventricular zone and axonal sprouting at the edge of the damaged area.We show that meloxicam’s neuroprotective effects remained after 7 days of reperfusion even if its administration was restricted to the two first days after ischemia.Moreover,meloxicam treatment modulated glial scar reactivity,which matched with an increase in axonal sprouting.However,this treatment decreased the formation of neuronal progenitor cells.This study discusses the dual role of anti-inflammatory treatments after stro ke and encourages the careful analysis of both the neuroprotective and the regenerative effects in preclinical studies.

Calculating detonation performance of explosives by VLWR thermodynamics code introduced with universal VINET equation of state

Thermodynamic calculation is the theoretical basis for the study of initiation and detonation,as well as the prerequisite for forecasting the detonation performance of unknown explosives.Based on the VLWR(Virial-Wu)thermodynamic code,this paper introduced the universal solid equation of state(EOS)VINET.In order to truly reflect the compressibility of nanocarbon under the extremely high-temperature and high-pressure environment in detonation,an SVM(support vector machine)was utilized to optimize the input parameters of carbon.The detonation performance of several explosives with different densities was calculated by the optimized universal EOS,and the results show that the thermodynamic code coupled with the universal solid EOS VINET can predict the detonation performance parameters of explosives well.To investigate the application of the thermodynamic code with the improved VINET EOS in the working capacity of explosives,the interrelationship between pressure P-particle velocity u and pressure P-volume V were computed for the detonation products of TNT and HMX-based PBX(HMX:binder:insensitive agent=95:4.3:0.7)in the CJ isentropic state.A universal curve proposed by Cooper was used to compared the computed isentropic state,where the ratio of pressure to CJ state were plotted against the ratio of velocity to CJ state.The parameters of the JWL(Jones-Wilkins-Lee)EOS for detonation products were obtained by fitting the P-V curve.The cylinder tests of TNT and HMX-based PBX were numerically simulated using the LS-DYNA,it is verified that,within a certain range,the improved algorithm has superiority in describing the working capacity of explosives.

Characterization of mudrocks:a practical application of advanced laboratory testing

An integrated approach to geomaterial characterization is advocated that combines geology, in-situ testing, fabric studies, routine index experiments and advanced laboratory testing. It is shown that advanced laboratory testing can explore features such as kinematic yielding and anisotropy in stiffness or shear strength that would otherwise be impossible to quantify. A detailed study performed in London clay at the new Heathrow Terminal 5 site is used to illustrate the arguments made. It is shown that the London clay has strong anisotropy in stiffness, is highly non-linear over the strain range of engineering interest, has markedly anisotropic shear strength characteristics and exhibits a pronounced degree of brittleness. These features can impact significantly on the practical design and analysis of civil engineering works including shallow and deep foundations, tunnels and excavations, and the stability of slopes.

Angle of repose in the numerical modeling of ballast particles focusing on particle-dependent specifications:Parametric study

The discrete element method(DEM)is widely used in the realistic simulation of the shapes of particles.Researchers have considered the simplification of particle shapes owing to the high computational cost of such simulation.In this regard,the modeling of calibrated particles is a major challenge owing to the simultaneous effects of particle properties.The angle-of-repose test is a standard test method used to calibrate the bulk behavior of simulated particles.In the present study,the hollow-cylinder(slump)test was modeled for the verification of discrete element simulations.In this regard,a sensitivity analysis was conducted for all effective parameters,namely the static friction,rolling friction,restitution coefficient,sphericity,roundness,particle size distribution,and number of ballast particles.The results indicate that the rolling friction,roundness,number of particles,and size of particles are the most important parameters in the determination of the angle of repose(AOR).For particles in the range of ballast(20-60 mm),the effect of the number of particles on the angle of repose is reduced when the number is greater than 426.Additionally,it is concluded that angular particles can be replaced with sub-angular particles(R≈0.2-0.45)with a higher rolling friction coefficient(μ_(r)>0.14).