[Retracted] Effect of Noninvasive Positive Pressure Ventilation on Prognosis and Blood Gas Level in COPD Patients Complicated with Respiratory Failure

Figure 4

ELISA results. Comparison of TNF-α levels (a), IL-6 levels (b), and IL-1β levels (c). Note: and # have the same meaning as in Figure 2.

(a)

(b)

(c)