Fine particulate matter (PM2.5) exposure is associated with morbidity and mortality induced by respiratory diseases and increases the lung cancer risk. However, the mechanisms therein involved are not yet fully clarified. In this study, the PM2.5 suspensions at different dosages (0.375, 1.5, 6.0, and 24.0 mg/kg body weight) were respectively given to rats by the intratracheal instillation. The results showed that PM2.5 exposure induced inflammatory cell infiltration and hyperemia in the lung tissues and increased the inflammatory cell numbers in bronchoalveolar lavage fluid. Furthermore, PM2.5 significantly elevated the levels of pro-inflammatory mediators including tumor necrosis factor-α (TNF-α), interleukin (IL)-6, IL-1β, and intercellular adhesion molecule 1 (ICAM-1) and the expression of c-fos and c-jun in rat lungs exposed to higher dose of PM2.5. These changes were accompanied by decreases of activities of superoxide dismutase and increases of levels of malondialdehyde, inducible nitric oxide synthase, nitric oxide, cytochrome P450s, and glutathione S-transferase. The results implicated that acute exposure to PM2.5 induced pathologically pulmonary changes, unchained inflammatory and oxidative stress processes, activated metabolic enzyme activity, and enhanced proto-oncogene expression, which might be one of the possible mechanisms by which PM2.5 pollution induces lung injury and may be the important determinants for the susceptibility to respiratory diseases.

A highly efficient and green process was developed for direct conversion of levulinic acid into 1,4-pentanediol over Mo-modified Ru/activated carbon (AC) catalyst in a continuous fixed-bed reactor. The Ru-MoO /AC catalyst was found to be efficient for the aqueous-phase hydrogenation of levulinic acid to 1,4-pentanediol, whereby a high yield (96.7 mol %) of 1,4-pentanediol was obtained under mild reaction conditions (70 °C, 4 MPa H ).

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Hazards are intrinsic to a material or its conditions of storage or use [Hendershot, D. C. Inherently safer chemical process design. J. Loss Prev. Process Ind. 1997, 10 (3), 151−157]. Inherently safer designs aim to avoid hazards by design, rather than by add-on measures. The importance of inherent safety has been increasingly stressed in chemical process industries in recent years. It is the most suitable safety approach, particularly in the process design stage. This paper describes a new comprehensive inherent safety index (CISI) for use in the early process design stage. The CISI assigns equipment safety scores to individual units in the process based on chemical, process, and connectivity scores. The chemical score considers the weighted severity score of each chemical in the unit as well as the reactivity score. The reactivity score is calculated separately for the mixture of chemicals in each unit. Since hazards can be compounded by the existence of highly interconnected units, the concept of the connectivity score is introduced. Case studies involving biodiesel and methyl methacrylate processes are used to demonstrate the new safety assessment methodology. The results of the assessment are used to compare the processes based on inherent safety, and they can potentially serve as a valuable aid to clearly identify key areas for improvement in a root-cause analysis.