A study on aviation supply chain network controllability and control effect based on the topological structure.

The present paper focuses on the controllability of the aviation supply chain network and establishes the judgment criterion for structural controllability of the aviation supply chain network. We determine the control effect by applying the control input to different nodes in the aviation supply chain network. These control nodes include the core enterprises of the aviation supply chain network, the upstream suppliers, and the downstream distributors. It is observed that the control effect is better when the control input is applied to the upstream suppliers of the aviation supply chain network than to the core enterprises of the aviation supply chain network. It is also more desirable to apply the control input to the core enterprises than to the distributors. That is, the control effect is the weakest when the control input is applied to the distributors, whereas the effect is best on application of the control to the upstream suppliers in the supply chain (that is, by choosing the upstream suppliers as the controlled nodes in the aviation supply chain network).

[Effects of two metabolites of cultured marine fungus, Halorosellinia oceanicum 323, on the contraction of isolated guinea-pig ileum].

AIM: To investigate the effects of 323-A and 323-B, two isomers extracted from the metabolites of cultured marine fungus, Halorosellinia oceanicum 323, on the contraction of isolated guinea pig ileum (GPI). METHODS: The GPI contractions were recorded with a two-channel-physiological recorder with tension transducers. Cumulative dose-response curves of contractions of isolated GPI induced by histamine (Hist), acetylcholine (ACh) and potassium chloride (KCl) were constructed, then the influences of 323-A and 323-B on each curve were observed. Furthermore, possible mechanisms underlying effects of the two compounds were explored by analyzing their influences on the biphasic contractile response to ACh, with comparison of a calcium antagonist, verapamil (Ver). RESULTS: The data indicated that both 323-A and 323-B inhibited the contractile actions of GPI triggered by Hist, ACh and KCl in a concentration-dependent manner, with pD2' values of 5.13, 4.97, 5.36 and 5.51, 5.56, 5.62, respectively. The initial phase component of the ACh-elicited contractions, in the absence of external Ca2+, was significantly reduced by 323-A, 323-B, as well as Ver, whereas the subsequent sustained tonic contractions induced by adding Ca2+ to the bath solution were almost unaffected. CONCLUSION: These results suggest that 323-A and 323-B have calcium antagonistic effects similar to that of Ver in mechanisms, and they might have potential to be developed as calcium antagonists.

Effects of resveratrol on secondary damages after acute spinal cord injury in rats.

AIM: To study the effects of resveratrol (Res) on secondary spinal cord edema, the activity of lactate dehydrogenase (LDH), Na+, K+-ATPase, and malondialdehyde (MDA) content in experimental spinal cord injured (SCI) rats. METHODS: The weight-dropping method was used to produce the experimental SCI in adult rats. Res ( 50, 100 mg/kg) and methylprednisolone (MPSS) 100 mg/kg were injected ip immediately after the induction of SCI. The effects of Res on edema, LDH, Na+, K+-ATPase, and MDA were determined at 1 h, 24 h, and 48 h after SCI compared with MPSS. The electron microscope was employed to investigate the ultrastructural effects of Res on axons, neurons, and subcellular organelles after SCI. RESULTS: Res obviously inhibited the secondary spinal cord edema with the most remarkable suppressing rate by 11.5 % at 48 h. Res significantly suppressed the activities of the lactate dehydrogenase with the highest suppressing rate > 40 % at 24 h. Res markedly improved the Na+, K+-ATPase activities that were promoted to the biggest extent of 60 % at 48 h. At the same time, Res (50 and 100 mg/kg) obviously reduced MDA production in the injured spinal cord tissue in comparison with the SCI model, the most remarkable effect of Res was detected at 48 h with the inhibitory rate >40 %. The ultrastructural findings suggested that SCI caused profound spinal cord damage, which could be protected or improved by injection of Res and MPSS. CONCLUSION: Both Res and MPSS effectively protected the spinal cord from secondary spinal cord injures. But the effects of Res 50 and 100 mg/kg were stronger in improving the energy metabolism system and inhibiting the lipid peroxidation in the local injured spinal cord after SCI than MPSS at the dose of 100 mg/kg. Res might have greatly potent therapeutic effects on SCI.