Systematic review and meta-analysis of adjunctive corticosteroids in the treatment of tuberculous pericarditis

SETTING

Tuberculosis (TB) is the most common cause of pericarditis worldwide and carries a high mortality, even with effective anti-tuberculosis treatment. In the light of a randomized control trial in 2014, the American Thoracic Society and the Centers for Disease Control and Prevention/Infectious Diseases Society of America recently revised their recommendations against the routine use of adjunctive corticosteroids.

OBJECTIVE

To evaluate the strength of evidence that resulted in this reversal of the guideline recommendations on the use of adjunctive corticosteroids in TB pericarditis by a meta-analysis, followed by a sensitivity analysis.

DESIGN

Systematic review and meta-analysis of published randomized control trials.

RESULTS

We identified five randomized control trials that met the eligibility criteria. Combining the results of the included trials, there was no overall mortality benefit from adjunctive corticosteroids (a random-effects model yielded a non-significant relative risk of 0.66 and 95%CI of 0.35-1.27). A sensitivity analysis further confirmed that the results of the meta-analysis were robust.

CONCLUSION

Routine addition of oral corticosteroids to standard anti-tuberculosis treatment does not reduce mortality among patients with TB pericarditis.

Spectral phonon scattering from sub-10 nm surface roughness wavelengths in metal-assisted chemically etched Si nanowires

Frequency dependence in phonon surface scattering is a debated topic in fundamental phonon physics. Recent experiments and theory suggest such a phenomenon, but an independent agreement between the two remains elusive. We report low-temperature dependence of thermal conductivity in silicon nanowires fabricated using a two-step, metal-assisted chemical etch. By reducing etch rates down to 0.5 nm/s from the typical >100 nm/s, we report controllable roughening of nanowire surfaces and selectively focus on moderate roughness scales rather than the extreme scales investigated previously. This critically enables direct comparison with perturbation-based spectral scattering theory. Using experimentally characterized surface roughness, we show that a multiple scattering theory provides excellent agreement and explanation of the observed low-temperature dependence of rough surface nanowires. The theory does not employ any fitting parameters. A 5-10 nm roughness correlation length is typical in metal-assisted chemical etching and resonantly scatters dominant phonons in silicon, leading to the observed ~T(1.6-2.4) behavior. Our work provides fundamental and quantitative insight into spectral phonon scattering from rough surfaces. This advances applications of nanowires in thermoelectric energy conversion.