多式联运路径问题的一种混合算法

【目的】针对多式联运过程中运输路径和运输方式的优选问题,以运输成本最少为目标,建立了含运到时限约束和路径容量约束的组合优化模型.【方法】针对模型设计了双信息素蚁群-遗传混合算法进行求解,并引入最大最小蚂蚁策略、自适应灾变算子等操作,适时规避局部最优解,以提高算法优化能力.【结果】将混合算法求得的结果与单遗传算法、蚁群算法进行比较,混合算法较另两者的收敛稳定性平均提升15.534%和12.537%,且求得的20次最小费用平均值分别降低了3.18%和1.38%.【结论】采用上述方法探讨运到时限、容量约束以及货物运量对路径选择的影响,从而为多式联运经营人决策提供了参考.

Upregulation of TREM2 attenuates neuroinflammation and dopaminergic neurotoxicity in MPTP model mice with Parkinson disease

OBJECTIVE To investigate the role of triggering receptor expressed on myeloid cells-2(TREM2) in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP) model mice with Parkinson disease(PD) and explore the underlying signaling pathway that mediate TREM2 function.METHODS TREM2 adenovirus were stereologically injected into the right striatum.Two weeks later,MPTP was intraperitoneally injected to produce the acute MPTP mouse model of PD.Mice were sacrificed at different time points following MPTP for biochemical or histological study.RESULTS Overexpression of TREM2 remarkably reduced MPTP-induced neuropathology including the dopaminergic neurodegeneration and neuroinflammation in vivo.Further study revealed that TREM2 may inhibit neuroinflammation by negatively regulating the TRAF6/TLR4-mediated activation of the MAPK and NF-κB signaling pathways.CONCLUSION TREM2 may have important neuroprotective effects against PD by critical y modulating neuroinflammatory responses.

Histone deacetylase 6 mediated NALP3 inflammasome activation contributes to dopaminergic injury in experimental models of Parkinson disease

OBJECTIVE To investigate the mechanisms of histone deacetylase 6(HDAC6)deacetylation activity on NALP3 inflammasome activation and explore the protective effect s of pharmacological inhibition of HDAC6 on dopaminergic injury.METHODS In vitro and in vivo6-OHDA induced Parkinson disease(PD) model was used.To distinguish the effect of deacetylase catalytic domains of HDAC6,we used a specific HDAC6 inhibitor tubastatin A(TBA),siRNAHDAC6,and pcDNA-HDAC6-FLAG plasmid.First,the role of pharmacological inhibition or siRNA or overexpression of HDAC6 on NALP3 inflammasome and cell death was explored by using Western blotting,TUNEL,and flow cytometric analysis.Then,the acetylation level of peroxiredoxin 2(Prx2) and the production of reactive oxygen species(ROS) in cells under different treatments was examined by using immunoprecipitation and DCFH-DA fluorescence assay.The effects of TBA on neuroinflammation and nigrostriatal dopaminergic system in vivo was further investigated by using Western blotting,immunohistochemistry and HPLC analysis.RESULTS TBA remarkably inhibited 6-OHDA induced NALP3 inflammasome activation,reduced dopaminergic neurodegeneration and neuroinflammation as demonstrated by increased TH-positive neurons,striatal levels of DA and its metabolites,and decreased gliocyte proliferation.TBA recovered acetylation of Prx2,and reduced ROS production,which was associated with decreased NALP3 inflammasome activation.CONCLUSION HDAC6 may medicate deacetylation of Prx2 contributes to NALP3 inflammasome activation in PD pathology,suggesting that the development of specific pharmacological inhibitors of HDAC6 be required for this kind of disease.

Urolithin A protects dopaminergic neurons in experimental models of Parkinson disease by promoting mitochondrial biogenesis through SIRT1/PGC-1αsignaling pathway

OBJECTIVE Mitochondrial dys⁃function contributes to the pathogenesis of neuro⁃degenerative diseases such as Parkinson dis⁃ease(PD).Therapeutic strategies targeting mito⁃chondrial dysfunction hold considerable promise for the treatment of PD.Urolithin A(UA)is a gut metabolite produced from ellagic acid-containing foods such as pomegranates,berries,and wal⁃nuts.Recent reports have highlighted the protec⁃tive role of UA in several neurological disorders including Alzheimer disease and ischemic stroke.However,the potential role of UA in PD has not been characterized.In this study,the role of UA in 6-OHDA-induced neurotoxicity in cell cultures and mouse model of PD was investi⁃gated.METHODS In vitro,PC12 cells were exposed to 6-OHDA in the presence or absence of UA.For in vivo study,C57BL/6 mice were ste⁃reotactic injected with 6-OHDA to induce experi⁃mental PD model.UA(10 mg·kg-1)was intraperi⁃toneal injected for 7 d before surgery.RESULTS UA protected against 6-OHDA cytotoxicity and apoptosis in PC12 cells.Prior administration of UA to 6-OHDA lesioned mice ameliorated both motor deficits and nigral-straital dopaminergic neurotoxicity.Moreover,UA attenuated 6-OHDA-induced mitochondrial dysfunction in PC12 cells accompanied by enhanced mitochondrial biogen⁃esis.Mechanically,the neuroprotective effects of UA were mediated by SIRT1-PGC-1αsignaling-mediated mitochondrial biogenesis.CONCLU⁃SION These data provide new insights into the novel role of UA in promoting mitochondria bio⁃genesis and suggest that UA may have potential therapeutic applications for PD.