Study on the effect of different aldehyde modifiers on the fume suppression effect, mechanism and road performance of SBS modified asphalt.

In order to curb asphalt fume emissions during the heating process of styrene-butadiene-styrene (SBS) asphalt, three aldehyde modifiers [vanillin (X), citral (N) and amyl cinnamaldehyde (J)] were blended into SBS-modified asphalt to prepare aldehyde-modified asphalt in this paper. By collecting solid particles and volatile organic compounds (VOCs) in asphalt fumes to conduct relevant experiments, we have analyzed the fume suppression effect and suppression mechanism of aldehyde modified asphalt, and finally examined the road performance of aldehyde modifiers with the best fume suppression effect. It was found that the average VOCs concentration of aldehyde modified asphalt was reduced by about 78 % after 30 min. Aldehyde modifiers significantly reduce the compositional type and content of VOCs in SBS asphalt and reduce the risk of carcinogenicity by curbing the emission of substances such as benzene and phenol. J asphalt reduced solid particle emissions from SBS asphalt fume by 31.4 % and outperformed both X and N asphalt in inhibiting the escape of solid particulate matter and carcinogens from asphalt fume. Polymer networks and the cross-linking of chemical molecules are the main reasons for inhibiting the escape of asphalt fume molecules. In addition, the J modifier enhanced the high-temperature stabilization and water-stability properties of asphalt mixtures, but slightly reduced the low-temperature cracking resistance. The results showed that the three aldehyde modifiers were effective in inhibiting the volatilization of fumes from SBS modified asphalt. Among them, with the best effect of curbing fume emissions and a better road performance, J-modified asphalt is promising for the application in asphalt fume prevention and emissions reduction, and provides a new solution to reduce construction pollution and physical harm caused by asphalt fume in the construction process.

Exhaust and evaporative volatile organic compounds emissions from vehicles fueled with ethanol-blended-gasoline.

By 2020, China has implemented the use of 10% ethanol-blended-gasoline (E10), which is expected to notably impact vehicular volatile organic compounds (VOCs) emissions. The adoption of E10 reduced certain emissions but raised concerns with about more reactive oxygenated volatile organic compounds (OVOCs). This study aimed to evaluate the impact of E10 on the total VOCs emissions from both exhaust and evaporative emissions by conducting tests on the CHINA V (or CHINA VI) light-duty gasoline vehicles (LDGVs) using 0% ethanol blended gasoline (E0) and E10. E10 reduces VOCs emissions in the exhaust, and reduces the ozone and secondary organic aerosol generation potential of VOCs in the exhaust, as evidenced by the lower emission factors (EFs), ozone formation potentials (OFPs) and secondary organic aerosol formation potential (SOAFPs) in the CHINA V LDGVs. Evaporative emissions showed differences in emitted VOCs, with lower EFs, OFPs and SOAFPs for the CHINA V LDGVs fueled with E10. The CHINA VI LDGVs also exhibited reduced EFs, OFPs and SOAFPs. These findings highlight the environmental benefits of E10 in the CHINA VI-compliant LDGVs; however, the effectiveness of the earlier CHINA V standard vehicles requires further evaluation.

Assessment of antiviral activity and mechanism of rhein on newcastle disease virus (La Sota strain IV) in vitro.

Current research is focused on the development of drug candidates from natural products. Rhein a Traditional Chinese Medicine (TCM) from Polygonaceae (rhubarb) has exhibited antioxidant, anti-inflammatory and anticancer activities, however no work has reported its antiviral potential, thus this study was performed to investigate the antiviral activities of rhein on new castle disease virus (NDV) in vitro.NDV infection of chicken embryo fibroblasts (CEFs) was prepared using 10-day-old specific pathogen free chicken embryos. Cytotoxicity and anti-viral activities of rhein were assessed using the MTT method. The interaction between NDV and cell membrane proteins were also detected using virus overlay protein binding assay (VOPBA). In addition NDV genes expressions in CEFs were measured using real-time fluorescent quantitative (RTFQ) PCR.The results showed that rhein effectively inhibit NDV activities maximal safe concentration of 0.125 mg/ml. This finding indicated that, rhein could be used as future antiviral drug against NDV.[Formula: see text].

Assessing the dry impinger method for condensable particulate matter from ultra-low emission coal-fired power plant measurement.

The dry impinger method is commonly used for the determination of condensable particulate matter (CPM) emissions. The coil and chamber condenser is used to build different dry impinger methods for CPM sampling. The comparative analysis of coil and chamber condenser is performed in a laboratory experiment to evaluate the deviation caused by SO2. Results showed that the positive deviation caused by SO2 in the chamber condenser is lower than that in the coil condenser under the same sampling conditions, especially under high humidity flue gas. The CPM emission characteristics from Hanchuan coal-fired power plant (CFPP) determined by both dry impinger methods are also investigated as well. The CPM and its most water-soluble ions (e.g., F-, Cl-, NO3-, SO42-, Na+, Ca2+ and NH4+) measured by method #2 (chamber condenser) are higher than that of method #1 (coil condenser). In addition, the esters in the CPM also increased with the CPM concentrations. Based on above evidences, it can be inferred that the dry impinger method with chamber condenser, will be recommended as the appropriate method for measuring CPM emitted from stationary sources, especially under the high humidity flue gas conditions.

[Effect of WESP on Emission Characteristics of Condensable Particulate Matter from Ultra-low Emission Coal-fired Power Plants].

In order to study the effect of wet electrostatic precipitators(WESP) on emission characteristics of condensable particulate matter (CPM) from ultra-low emission coal-fired power plants that are under different capacity conditions, a set of CPM sampling devices was built based on US EPA Method 202, and an ultra-low emission coal-fired power plant was detected. This study evaluated the emission level of the CPM from the flue gas of coal-fired power plants, the effects of different unit capacity conditions on the CPM emission concentrations, and the removal efficiency of WESP for different components of the CPM. The results suggested that the emission concentrations of the CPM from ultra-low emission power plants were 27.27 mg·m-3 and 28.71 mg·m-3under the conditions of 75% and 100% capacity, respectively. The removal efficiencies of WESP for the CPM were 35.59% and 27.59%, respectively. SO42- was the main component of water-soluble ions of the CPM. The proportion of SO42- in inorganic components of the CPM reached more than 65% under different capacity conditions. In addition, the removal efficiency of WESP for Cl-, K+, Ca2+, Mg2+, Na+, and other inorganic ions reached 30%-50%, but the mass concentrations of SO42- and NO3- increased.

Simultaneous removal of T and B cell epitope in recombinant staphylokinase by structure-based mutagenesis of immuno-dominant Arg77 and Glu80 residues.

OBJECTIVE: To reduce immunogenicity of recombined staphylokinase (r-Sak) , site-directed mutagenesis of Arg77 and Glu80 residue was performed to simultaneously remove T and B cell epitope in r-Sak molecule. METHODS: The solvent accessible surface areas of residues 77 and 80 in r-Sak were used to analyze rational design of Sak mutation. The Sak mutants were expressed in E coli DH5alpha. After purified by a 3-step chromatography, their fibrinolytic activities and immunological properties were analyzed. RESULTS: Immunogenicity tests suggested that Sak induced a Th2-type immune response. Substitution of Glu80 with alanine or serine successfully reduced its solvent accessible surface area while simultaneously removing part of the T and B cell epitope. Changing Arg77 to glutamine, asparagine, or lysine removed only part of the T cell epitope. Of six dually substituted variants, Sak (R77Q/E80A) and Sak(R77Q/E80S) variants effectively eliminated part of the B and T cell epitopes, which markedly reduced their immunogenicity.

Simultaneous elimination of T- and B-cell epitope by structure-based mutagenesis of single Glu80 residue within recombinant staphylokinase.

To reduce the immunogenicity of recombinant staphylokinase, structure-based mutagenesis of Glu80 residue in wild-type staphylokinase (wt-Sak) was rationally designed and carried out by a modified QuikChange site-directed mutagenesis. Sak mutants, including Sak(E80A) and Sak(E80S), were successfully expressed in E. coli DH5a as a soluble cytoplasmic proteins and accounted for more than 40% of the total cellular proteins. The expressed proteins were purified by a three-step chromatographic purification process. SDS-PAGE and HPLC analyses results indicated that the purified proteins were almost completely homogeneous and the purities of Sak mutants exceeded 97%. Analysis of fibrinolytic activity revealed that substitution of E80 residue with serine and alanine resulted in slightly increased specific activities of Sak mutants. Investigation of the immunogenicity of Sak mutants showed that the amount of specific anti-Sak IgG antibodies elicited by Sak(E80A) and Sak(E80S) in BALB/c mice decreased approximately 35% and 27%, respectively compared with wt-Sak. The abilities of Sak mutants to stimulate proliferation of T cells from BALB/c mice and to bind mouse anti-Sak polyclonal serum were significantly lower than those of wt-Sak. These results suggested that substitution of Glu80 residue by alanine and serine successfully eliminated part of T- and B-cell epitope of Sak molecule. Our findings suggested that simultaneous elimination of T- and B-cell epitopes was a useful method to reduce the immunogenicity of wt-Sak molecule and provided a strategy for engineering safe Sak-based fibrinolytics for the clinical treatment of acute myocardial infarction.

Novel recombinant thrombolytic and antithrombotic staphylokinase variants with an RGD motif at their N-termini.

To develop a more potent thrombolytic agent, four Sak (staphylokinase) variants were constructed, in which RGD (Arg-Gly-Asp) sequences are introduced into diferent sites of the N-terminus of Sak. These variants were successfully expressed in Escherichia coli DH5alpha as soluble cytoplasmic proteins in a 5-litre fermentor and accounted for more than 40% of the total cellular protein. The expressed proteins were subsequently purified, employing a similar three-step chromatographic purification process. SDS/PAGE and HPLC-MS analyses indicated that the purified proteins were almost completely homogeneous, the purity of the variants exceeding 95%. Further investigations into the properties of the Sak variants showed that mutations at the N-terminus significantly affected N-terminal methionine excision, and serine residues at the N-terminus of Sak appeared to play an important role in the process. Kinetic analysis of r-Sak (recombinant Sak) and its variants using plasminogen as substrate indicated that the mutations affected the proteolysis. In addition, a significant inhibitory effect of the Sak variants at 2.0 muM was observed on the ADP-induced aggregation of platelets compared with that of r-Sak, whether N-terminally cleaved or not (P<0.05). Furthermore, the inhibitory activity of Sak variants after N-terminal proteolysis was higher than that of native Sak variants.

Effect of biomass burning on black carbon (BC) in South Asia and Tibetan Plateau: The analysis of WRF-Chem modeling.

The focus of this study is to evaluate the impact of biomass burning (BB) from South Asia and Southeast Asia on the glaciers over the Tibetan Plateau. The seasonality and long-term trend of biomass fires measured by Terra and Aqua satellite data from 2010 to 2016 are used in this study. The analysis shows that the biomass burnings were widely dispersed in the continental of Indian and Southeast Asia and existed a strong seasonal variation. The biomass burnings in winter (January) were relatively weak and scattered and were significantly enhanced in spring (April). The highest biomass burnings located in two regions. One was along the foothill of Himalayas, where is a dense population area, and the second located in Southeast Asia. Because these two high biomass burning regions are close to the Tibetan Plateau, they could have important effects on the BC deposition over the glaciers of the Tibetan Plateau. In order to study the effect of BB emissions on the deposition over the glaciers in the Tibetan Plateau, a regional chemical model (WRF-Chem; Weather Research and Forecasting Chemical model) was applied to simulate the BC distributions and the transport from BB emission regions to the glaciers in Tibetan Plateau. The result shows that in winter (January), due to the relatively weak BB emissions, the effect of BB emissions on BC concentrations was not significant. The BC concentrations resulted from BB emissions ranged from 0.1 to 2.0 µg/m3, with high concentrations distributed along the foothill of Himalayas and the southeastern Asia region. Due to the relative low BC concentrations, there was insignificant effect of BB emissions on the deposition over the glaciers in the Tibetan Plateau in winter. However, the BB emissions were highest in spring (April), producing high BC concentrations. For example, along the Himalayas Mountain and in the southeastern Asia region, The BC concentrations ranged from 2.0 to 6.0 µg/m3. In addition to the high BC concentrations, there were also west and south prevailing winds in these regions. As a result, the BC particles were transported to the glaciers in the Tibetan Plateau, causing significant deposition of BC particles on the snow surface of the glaciers. This study suggests that the biomass burning emissions have important effects on the BC deposition over the glaciers in the Tibetan Plateau, and the contaminations of glaciers could have significant impact on the melting of snow in the Tibetan Plateau, causing some severe environmental problems, such as the water resources.

Anti-NDV activity of 9-oxo10,11-dehydroageraphorone extracted from Eupatorium adenophorum Spreng in vitro.

The purpose of this study was to investigate the anti-Newcastle disease virus (NDV) activities of 9-oxo-10,11-dehydroageraphorone (euptox A) from Eupatorium adenophorum Spreng (E. adenophorum) in vitro. NDV infection of chicken embryo fibroblasts (CEFs) was performed. Cytotoxicities and antiviral activities of euptox A was assessed by the MTT method. The interaction of NDV with cell membrane protein was detected by virus overlay protein binding assay (VOPBA). The expression levels of NDV genes in CEFs was tested by RTFQ PCR. The results showed that the maximal safe concentrations of euptox A to CEFs was 10 µg/mL. Euptox A could directly neutralise NDV, inhibit the infectivity of NDV to CEFs and block intracellular NDV treat NDV infection. And euptox A brings competitiveness inhibition for NDV binding to its receptors and then prevent NDV infection. These results indicated that euptox A possessed anti-NDV activity has potential use as components of a natural antiviral drug.

Effect of hydrolysis of N2O5 on nitrate and ammonium formation in Beijing China: WRF-Chem model simulation.

Beijing, the capital of China, is a mega city with a population of >20 million. In recent years, the city has experienced heavy air pollution, with particulate matter (PM) being one of its top pollutants. In the last decade, extensive efforts have been made to characterize the sources, properties, and processes of PM in Beijing. Despite progress made by previous studies, there are still some important questions to be answered and addressed. The focus of this research is to study the impact of the heterogeneous hydrolysis of N2O5 on the formation of nitrate (NO3-) and ammonium (NH4+) in Beijing. The results show that during heavy pollution days (e.g., during 14-17 September 2015, with PM2.5 concentration over 100µg/m3), the concentrations of NO2 and O3 were high, with maxima of 90 and 240µg/m3, respectively, providing high precursors for the formation of N2O5. In addition, the aerosol and sulfate concentrations were also high, with maxima of 201µg/m3 and 23µg/m3 respectively, providing reacting surface for the heterogeneous reaction. As a result, the hydrolysis of N2O5 led to 21.0% enhancement of nitrate (NO3-) and 7.5% enhancement of ammonium (NH4+). It is worth to note that this important effect only occurred in high pollution days (PM2.5 concentration over 100µg/m3). During low-pollution periods (PM2.5 concentration <100µg/m3), the effect of hydrolysis of N2O5 on the formation of nitrate and ammonium was insignificant (variation rate <5%). This study suggests that during heavy pollution periods, the hydrolysis of N2O5 enhances the level of aerosol pollution in Beijing, and needs to be further studied in order to perform efficient air pollution control and mitigation strategies.

Euptox A Induces G1 Arrest and Autophagy via p38 MAPK- and PI3K/Akt/mTOR-Mediated Pathways in Mouse Splenocytes.

Euptox A (9-oxo-10, 11-dehydroageraphorone), the main toxin isolated from Eupatorium adenophorum, is known to induce immunotoxicity in animals. However, the precise mechanism underlying the effects of Euptox A on splenocytes is unclear. Here, we aimed to investigate the molecular mechanisms underlying the effect of Euptox A in mouse spleens after its intragastric administration and found that Euptox A exhibits proautophagic effects in splenocytes. Euptox A markedly arrested the splenocytes in the G0/G1 phase, which was accompanied by inhibition of the expression of the positive regulators CDK4, CDK2, cyclin D1, PCNA, and E2F1, and promotion of the expression of the negative regulators p53, p21 Waf1/Cip1, p27 Kip1, and Chk1. We also found that Euptox A did not markedly induce splenocyte apoptosis, but induced autophagy while increasing the subcellular localization of punctate LC3, ratio of LC3-II/LC3-I, and Beclin 1 levels, and decreasing p62 levels. Euptox A also significantly inhibited p-PI3K, p-p38 MAPK, p-Akt, and p-mTOR expression, but increased PTEN and p-AMPK expression. These results indicated that Euptox A induced splenocyte autophagy by inhibiting the PI3K/Akt/mTOR pathway, suppressing p38 MAPK expression, and activating AMPK. These findings provide new insights into the mechanisms involved in spleen toxicity caused by Euptox A in mice.

Analysis of a long-term measurement of air pollutants (2007-2011) in North China Plain (NCP); Impact of emission reduction during the Beijing Olympic Games.

Five years measurements were used to evaluate the effect of emission controls on the changes of air pollutants in Beijing and its surroundings in the NCP during 2008 Olympic Games (2008OG). The major challenge of this study was to filter out the effect of variability of meteorological conditions, when compared the air pollutants during the game to non-game period. We used four-year (2007, 2009-2011) average as the Non-2008OG to smooth the temporal variability caused by meteorological parameters. To study the spatial variability and regional transport, 6 sites (urban, rural, a mega city, a heavy industrial city, and a remote site) were selected. The result showed that the annually meteorological variability was significantly reduced. Such as, in BJ the differences between 2008OG and 5-years averaged values were 2.7% for relative humidity and 0.6% for wind speed. As a result, the anomaly of air pollutants between 2008OG and Non-2008OG can largely attribute to the emission control. The comparison showed that the major pollutants (PM10, PM2.5, NO, NOx) at the 6 sites in 2008OG were consistently lowered. For example, PM2.5 in BJ decreased from 75 to 45 µg/m(3) (40% reduction). However, the emission controls had minor effect on O3 concentrations (1% reduction). In contrast, the O3 precursor (NOx) reduced from 19.7 to 13.2 ppb (33% reduction). The in-sensitivity between NOx and O3 suggested that the O3 formation was under VOCs control condition in NCP, showing that strong VOC emission control is needed in order to significantly reduce O3 concentration in the region.

Anti-NDV activity of baicalin from a traditional Chinese medicine in vitro.

The purpose of this study was to investigate the anti-Newcastle disease virus (NDV) activities of baicalin from Scutellaria baicalensis, a Traditional Chinese Medicine in vitro. Chicken embryo fibroblasts (CEFs) were infected with NDV, and quantitative analysis of apoptotic cells was performed using flow cytometry. Cytotoxicity and anti-viral activities of baicalin were studied using the MTT method. The results showed that the maximal safe concentrations of baicalin to CEFs was 1 × 2(-2) mg/ml. Baicalin could directly kill NDV, inhibit the infectivity of NDV to CEF and block intracellular NDV. It inhibited the apoptosis of NDV-infected CEFs and suppressed the spread of NDV. These results indicate that baicalin has strong anti-NDV activity and has the potential for use as components of an antiviral drug.

Induction of apoptosis and autophagy via mitochondria- and PI3K/Akt/mTOR-mediated pathways by E. adenophorum in hepatocytes of saanen goat.

E. adenophorum has reported to cause hepatotoxicity. But, the precise effects of E. adenophorum on hepatocytes is unclear. Saanen goats were fed on E. adenophorum to detect the cytotoxicity effects of E. adenophorum on hepatocytes. Our study has shown that the typical apoptotic features, the increasing apoptotic hepatocytes and activated caspase-9, -3 and the subsequent cleavage of PARP indicated the potent pro-apoptotic effects of E. adenophorum. Moreover, the translocation of Bax and Cyt c between mitochondria and cytosol triggering the forming of apoptosome proved that the mitochondria-mediated apoptosis was triggered by E. adenophorum. Furthermore, E. adenophorum increased the MDC-positive autophagic vacuoles and the subcellular localization of punctate LC3, the ratio of LC3-II/LC3-I and the protein levels of Beclin 1, but decreased that of P62, indicating the potent pro-autophagic effects of E. adenophorum. In addition, E. adenophorum significantly inhibited the protein leves of p-PI3K, p-Akt and p-mTORC1, but increased PTEN and p-AMPK. Also, the p-mTORC2 and p-Akt Ser473 were inhibited, indicating that the supression of mTORC2/Akt pathway could induce the autophagy of hepatocytes. The autophagy-realted results indicated that the inhibition of PI3K/Akt/mTORC1- and mTORC2/Akt-mediated pathways contributed to the pro-autophagic activity of E. adenophorum. These findings provide new insights to understand the mechanisms involved in E. adenophorum-caused hepatotoxicity of Saanen goat.

E. adenophorum induces Cell Cycle Arrest and Apoptosis of Splenocytes through the Mitochondrial Pathway and Caspase Activation in Saanen Goats.

The precise cytotoxicity of E. Adenophorum in relation to the cell cycle and apoptosis of splenocytes in Saanen goats remains unclear. In the present study, 16 Saanen goats were randomly divided into four groups, which were fed on 0%, 40%, 60% and 80% E. adenophorum diets. The results of TUNEL, DAPI and AO/EB staining, flow cytometry analysis and DNA fragmentation assays showed that E. adenophorum induced typical apoptotic features in splenocytes, suppressed splenocyte viability, and caused cell cycle arrest in a dose-dependent manner. However, westernblot, ELISA, qRT-PCR and caspase activity analyses showed that E. adenophoruminhibited Bcl-2 expression, promoted Bax translocation to the mitochondria, triggered the release of Cytc from the mitochondria into the cytosol, and activated caspase-9 and -3 and the subsequent cleavage of PARP. Moreover, in E. adenophorum-induced apoptosis, the protein levels of Fas, Bid, FasL and caspase-8 showed no significant changes. E. adenophorum treatment induced the collapse of ΔΨm. Moreover, these data suggested that E. adenophorum induces splenocyte apoptosis via the activation of the mitochondrial apoptosis pathway in splenocytes. These findings provide new insights into the mechanisms underlying the effects of E. adenophorum cytotoxicity on splenocytes.

E. adenophorum Induces Cell Cycle and Apoptosis of Renal Cells through Mitochondrial Pathway and Caspase Activation in Saanen Goat.

The cytotoxicity effects of E. adenophorum on cell cycle and apoptosis of renal cells in Saanen goat was evaluated by TUNEL, DAPI, AO/EB staining, DNA fragmentation assay, Caspase activity, Western-blot, qRT-PCR and flow cytometry analysis. 16 saanen goats randomly divided into four groups were fed on 0%, 40%, 60% and 80% E. adenophorum diets. The Results showed that E. adenophorum induced typical apoptotic features of renal cells. E. adenophorum significantly suppressed renal cells viability, caused cell cycle activity arrest and induced typical apoptotic features in a dose-dependent manner. However, the protein levels of Fas/FasL, Bid and caspase-8 did not appear significant changes in the process of E. adenophorum-induced apoptosis. Moreover, E. adenophorum administration slightly decreased Bcl-2 expression, promoted Bax translocation to mitochondria, triggered the release of Cyt c from mitochondria into cytosol and activated caspase-9, -3, and cleaved PARP. The mitochondrial p53 translocation was significantly activated, accompanied by a significant increase in the loss of ΔΨm, Cyt c release and caspase-9 activation. Above all, these data suggest that E. adenophorum induces renal cells apoptosis via the activation of mitochondria-mediated apoptosis pathway in renal cells. These findings may provide new insights to understand the mechanisms involved in E. adenophorum-caused cytotoxicity of renal cells.

Refolding of a staphylokinase variant y1-Sak by reverse dilution.

To develop more potent thrombolytic agents with fibrinolytic and antiplatelet aggregation activity, staphylokinase (Sak) variant Y1-Sak, a recombinant mutant of the Staphylococcus aureus protein Sak, was constructed. Y1-Sak formed an insoluble inclusion body when overexpressed in Escherichia coli strain JF1125. To obtain an optimized refolding process, dilution refolding was used to optimize refolding conditions. The results revealed that additive L: -arginine and refolding temperature played critical roles in the refolding of Y1-Sak. Subsequently, two refolding methods, gel filtration and reverse dilution, were investigated to refold Y1-Sak. The results indicated that the fibrinolytic activity and recovery of Y1-Sak from gel filtration were lower than those from reverse dilution. Reverse dilution refolding successfully reduced the side reaction of refolding with the help of L: -arginine, and the fibrinolytic activity and recovery of Y1-Sak were significantly improved. Functional analysis revealed that refolded Y1-Sak by reverse dilution possessed fibrinolytic and antiplatelet aggregation activities. Moreover, the immunogenicity of Y1-Sak was significantly reduced.