A Study of Phytoplankton Community Structure in Duobukuer Nature Reserve

In spring,summer,autumn 2015,we studied the seasonal variation of phytoplankton community structure in six rivers within Duobukuer Nature Reserve,and made preliminary evaluation of the water quality in Duobukuer Nature Reserve based on phytoplankton diversity.The results showed that a total of 7 phyla,41 genera,66 species and varieties of phytoplankton were identified in Duobukuer Nature Reserve;the annual species composition was dominated by diatom( 59%) which also preponderated in dominant species( 84. 3%),biomass( 68%)and abundance( 75%),with no significant seasonal variation. Shannon-Wiener diversity index( H') and Pielou evenness index( J) were used to evaluate the water quality in 13 sampling points,and the results showed that the water quality was good in Duobukuer Nature Reserve,the sampling points 5,6 and 12 presented β-pollution,and other sampling points were in an oligosaprobic-clean state.

Endoplasmic reticulum stress-induced NLRP3 inflammasome activation as a novel mechanism of polystyrene microplastics (PS-MPs)-induced pulmonary inflammation in chickens

Microplastics(MPs)have attracted growing attention worldwide as an increasingly prevalent environmental pollutant.In addition,chicken meat is currently the most widely consumed kind of poultry in the global market.Consumer demand for chicken is on the rise both at home and abroad.As a result,the safety of chicken raising has also received significant attention.The lungs play an essential role in the physiological activities of chickens,and they are also the most vulnerable organs.Lung injury is difficult to repair after the accumulation of contaminants,and the mortality rate is high,which brings huge economic losses to farmers.The research on the toxicity of MPs has mainly focused on the marine ecosystem,while the mechanisms of toxicity and lung damage in chickens have been poorly studied.Thus,this study explored the effects of exposure to polystyrene microplastics(PS-MPs)at various concentrations for 42 d on chicken lungs.PS-MPs could cause lung pathologies and ultrastructural abnormalities,such as endoplasmic reticulum(ER)swelling,inflammatory cell infiltration,chromatin agglutination,and plasma membrane rupture.Simultaneously,PS-MPs increased the expression of genes related to the heat shock protein family(Hsp60,Hsp70,and Hsp90),ER stress signaling(activating) transcription factor 6(ATF0),ATF4,protein kinase RNA-like ER kinase(PERK),and eukaryotic translation initiation factor 2 subunitα(eIF2a),pyroptosis-related genes(NOD)-,LRR-and pyrin domain-containing protein 3(NLRP3),apoptosis-associated speck-like protein containing a caspase recruitment domain(ASC),interleukin-1β(IL-1β),cysteinyl aspartate-specific proteinase 1(Caspasel),and gasdermin-D(GSDMD),and the inflammatory signaling pathway(nuclear factor-kB(NF-kB),inducible nitric oxide synthase(iNOS),and cyclooxygenase-2(COX-2).The above results showed that PS-MP exposure could result in lung stress,ER stress,pyroptosis,and inflammation in broilers.Our findings provide new scientific clues for further research on the mechanisms of physical health and toxicology regardingMPs.

Release of deposited MnO2 nanoparticles from aqueous surfaces

Changes in solution chemistry and transport conditions can lead to the release of deposited MnO2 nanoparticles from a solid interface,allowing them to re-enter the aqueous environment.Understanding the release behavior of Mn02 nanoparticles from naturally occurring surfaces is critical for better prediction of the transport potential and environmental fate of Mn02 nanoparticles.In this study,the release of Mn02 nanoparticles was investigated using a quartz crystal microbalance with dissipation monitoring(QCM-D),and different environmental surface types,solution pH values and representative macromolecular organics were considered.Mn02 nanoparticles were first deposited on crystal sensors at elevated NaN03 concentrations before being rinsed with double-deionized water to induce their remobilization.The results reveal that the release rate of Mn02 depends on the surface type,in the decreasing order:SiO2>Fe304>Al2 O3,resulting from electrostatic interactions between the surface and particles.Moreover,differences in solution pH can lead to variance in the release behavior of Mn02 nanoparticles.The release rate from surfaces was significantly higher at pH 9.8 that at 4.5,indicating that alkaline conditions were more favorable for the mobilization of Mn02 in the aquatic environment.In the presence of macromolecular organics,bovine serum albumin(BSA)can inhibit the release of Mn02 from the surfaces due to attractive forces.In presence of humic acid(HA)and sodium alginate(SA),the Mn02 nanoparticles were more likely to be mobile,which may be associated with a large repulsive barrier imparted by steric effects.