The effect of Vasohibin-1 expression and tumor-associated macrophages on the angiogenesis in vitro and in vivo

Peer reviewe

Panorama-Based Multilane Recognition for Advanced Navigation Map Generation

Precise navigation map is crucial in many fields. This paper proposes a panorama based method to detect and recognize lane markings and traffic signs on the road surface. Firstly, to deal with the limited field of view and the occlusion problem, this paper designs a vision-based sensing system which consists of a surround view system and a panoramic system. Secondly, in order to detect and identify traffic signs on the road surface, sliding window based detection method is proposed. Template matching method and SVM (Support Vector Machine) are used to recognize the traffic signs. Thirdly, to avoid the occlusion problem, this paper utilities vision based ego-motion estimation to detect and remove other vehicles. As surround view images contain less dynamic information and gray scales, improved ICP (Iterative Closest Point) algorithm is introduced to ensure that the ego-motion parameters are consequently obtained. For panoramic images, optical flow algorithm is used. The results from the surround view system help to filter the optical flow and optimize the ego-motion parameters; other vehicles are detected by the optical flow feature. Experimental results show that it can handle different kinds of lane markings and traffic signs well

Quantifying evolution of soot mixing state from transboundary transport of biomass burning emissions

Incomplete combustion of fossil fuels and biomass burning emit large amounts of soot particles into the troposphere. The condensation process is considered to influence the size (Dp) and mixing state of soot particles, which affects their solar absorption efficiency and lifetimes. However, quantifying aging evolution of soot remains hampered in the real world because of complicated sources and observation technologies. In the Himalayas, we isolated soot sourced from transboundary transport of biomass burning and revealed soot aging mechanisms through microscopic observations. Most of coated soot particles stabilized one soot core under Dp &lt; 400 nm, but 34.8% of them contained multi-soot cores (nsoot ≥ 2) and nsoot increased 3–9 times with increasing Dp. We established the soot mixing models to quantify transformation from condensation- to coagulation-dominant regime at Dp ≈ 400 nm. Studies provide essential references for adopting mixing rules and quantifying the optical absorption of soot in atmospheric models.</p

Nicotianamine, a Novel Enhancer of Rice Iron Bioavailability to Humans

Background: Polished rice is a staple food for over 50 % of the world’s population, but contains little bioavailable iron (Fe) to meet human needs. Thus, biofortifying the rice grain with novel promoters or enhancers of Fe utilization would be one of the most effective strategies to prevent the high prevalence of Fe deficiency and iron deficiency anemia in the developing world. Methodology/Principal Findings: We transformed an elite rice line cultivated in Southern China with the rice nicotianamine synthase gene (OsNAS1) fused to a rice glutelin promoter. Endosperm overexpression of OsNAS1 resulted in a significant increase in nicotianamine (NA) concentrations in both unpolished and polished grain. Bioavailability of Fe from the high NA grain, as measured by ferritin synthesis in an in vitro Caco-2 cell model that simulates the human digestive system, was twice as much as that of the control line. When added at 1:1 molar ratio to ferrous Fe in the cell system, NA was twice as effective when compared to ascorbic acid (one of the most potent known enhancers of Fe bioavailability) in promoting more ferritin synthesis. Conclusions: Our data demonstrated that NA is a novel and effective promoter of iron utilization. Biofortifying polished rice with this compound has great potential in combating global human iron deficiency in people dependent on rice for thei

Micro RNA expression profile and functional analysis reveal that mi R ‐382 is a critical novel gene of alcohol addiction

Alcohol addiction is a major social and health concern. Here, we determined the expression profile of microRNAs (miRNAs) in the nucleus accumbens (NAc) of rats treated with alcohol. The results suggest that multiple miRNAs were aberrantly expressed in rat NAc after alcohol injection. Among them, miR‐382 was down‐regulated in alcohol‐treated rats. In both cultured neuronal cells in vitro and in the NAc in vivo , we identified that the dopamine receptor D1 ( Drd1 ) is a direct target gene of miR‐382. Via this target gene, miR‐382 strongly modulated the expression of DeltaFosB. Moreover, overexpression of miR‐382 significantly attenuated alcohol‐induced up‐regulation of DRD1 and DeltaFosB, decreased voluntary intake of and preference for alcohol and inhibited the DRD1‐induced action potential responses. The results indicated that miRNAs are involved in and may represent novel therapeutic targets for alcoholism. The underlying molecular causes of alcohol addiction remain unclear. Many miRNAs are found modulated in the nucleus accumbens of rats chronically treated with alcohol. Specifically, miR‐382 is shown to regulate alcohol intake via DRD1 and DeltaFosB.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/99635/1/emmm201201900-sm-0001-Review_Process_File.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99635/2/emmm201201900.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99635/3/emmm201202100-sm-0006-SourceData-S5.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99635/4/emmm201201900-sm-0002-SuppData-S1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99635/5/emmm201202100-sm-0005-SourceData-S4.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99635/6/emmm201202100-sm-0004-SourceData-S3.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99635/7/emmm201202100-sm-0003-SourceData-S2.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99635/8/emmm201202100-sm-0007-SourceData-S6.pd

Low-NO atmospheric oxidation pathways in a polluted megacity

The impact of emissions of volatile organic compounds (VOCs) to the atmosphere on the production of secondary pollutants, such as ozone and secondary organic aerosol (SOA), is mediated by the concentration of nitric oxide (NO). Polluted urban atmospheres are typically considered to be “high-NO” environments, while remote regions such as rainforests, with minimal anthropogenic influences, are considered to be “low NO”. However, our observations from central Beijing show that this simplistic separation of regimes is flawed. Despite being in one of the largest megacities in the world, we observe formation of gas- and aerosol-phase oxidation products usually associated with low-NO “rainforest-like” atmospheric oxidation pathways during the afternoon, caused by extreme suppression of NO concentrations at this time. Box model calculations suggest that during the morning high-NO chemistry predominates (95 %) but in the afternoon low-NO chemistry plays a greater role (30 %). Current emissions inventories are applied in the GEOS-Chem model which shows that such models, when run at the regional scale, fail to accurately predict such an extreme diurnal cycle in the NO concentration. With increasing global emphasis on reducing air pollution, it is crucial for the modelling tools used to develop urban air quality policy to be able to accurately represent such extreme diurnal variations in NO to accurately predict the formation of pollutants such as SOA and ozone

Observations of speciated isoprene nitrates in Beijing: implications for isoprene chemistry

Isoprene is the most important biogenic volatile organic compound in the atmosphere. Its calculated impact on ozone (O3) is critically dependent on the model isoprene oxidation chemical scheme, in particular the way the isoprene-derived organic nitrates (IN) are treated. By combining gas chromatography with mass spectrometry, we have developed a system capable of separating and unambiguously measuring individual IN isomers. In this paper we use measurements from its first field deployment, which took place in Beijing as part of the Atmospheric Pollution and Human Health in a Chinese Megacity programme, to test understanding of the isoprene chemistry as simulated in the Master Chemical Mechanism (MCM) (v.3.3.1). Seven individual isoprene nitrates were identified and quantified during the campaign: two β-hydroxy nitrates (IHN), four δ-carbonyl nitrates (ICN), and propanone nitrate. Our measurements show that in the summertime conditions experienced in Beijing the ratio of (1-OH, 2-ONO2)-IHN to (4-OH, 3-ONO2)-IHN (the numbers indicate the carbon atom in the isoprene chain to which the radical is added) increases at NO mixing ratios below 2 ppb. This provides observational field evidence of the redistribution of the peroxy radicals derived from OH oxidation of isoprene away from the kinetic ratio towards a new thermodynamic equilibrium consistent with box model calculations. The observed amounts of δ-ICN demonstrate the importance of daytime addition of NO3 to isoprene in Beijing but suggest that the predominant source of the δ-ICN in the model (reaction of NO with δ-nitrooxy peroxy radicals) may be too large. Our speciated measurements of the four δ-ICN exhibit a mean C1 : C4 isomer ratio of 1.4 and a mean trans : cis isomer ratio of 7 and provide insight into the isomeric distribution of the δ-nitrooxy peroxy radicals. Together our measurements and model results indicate that propanone nitrate was formed from the OH oxidation of δ-ICN both during the day and night, as well as from NO3 addition to propene at night. This study demonstrates the value of speciated IN measurements in testing understanding of the isoprene degradation chemistry and shows how more extensive measurements would provide greater constraints. It highlights areas of the isoprene chemistry that warrant further study, in particular the impact of NO on the formation of the IHN and the NO3-initiated isoprene degradation chemistry, as well as the need for further laboratory studies on the formation and the losses of IN, in particular via photolysis of δ-ICN and hydrolysis

Evaluating the sensitivity of radical chemistry and ozone formation to ambient VOCs and NOxin Beijing

Measurements of OH, HO2, complex RO2 (alkene-and aromatic-related RO2) and total RO2 radicals taken during the integrated Study of AIR Pollution PROcesses in Beijing (AIRPRO) campaign in central Beijing in the summer of 2017, alongside observations of OH reactivity, are presented. The concentrations of radicals were elevated, with OH reaching up to 2:8 × 107 molecule cm-3, HO2 peaking at 1 × 109 molecule cm-3 and the total RO2 concentration reaching 5:5×109 molecule cm-3. OH reactivity (k.OH/) peaked at 89 s-1 during the night, with a minimum during the afternoon of 22s-1 on average. An experimental budget analysis, in which the rates of production and destruction of the radicals are compared, highlighted that although the sources and sinks of OH were balanced under high NO concentrations, the OH sinks exceeded the known sources (by 15 ppbvh-1) under the very low NO conditions (< 0:5ppbv) experienced in the afternoons, demonstrating a missing OH source consistent with previous studies under high volatile organic compound (VOC) emissions and low NO loadings. Under the highest NO mixing ratios (104 ppbv), the HO2 production rate exceeded the rate of destruction by 50ppbvh-1, whilst the rate of destruction of total RO2 exceeded the production by the same rate, indicating that the net propagation rate of RO2 to HO2 may be substantially slower than assumed. If just 10 % of the RO2 radicals propagate to HO2 upon reaction with NO, the HO2 and RO2 budgets could be closed at high NO, but at low NO this lower RO2 to HO2 propagation rate revealed a missing RO2 sink that was similar in magnitude to the missing OH source. A detailed box model that incorporated the latest Master Chemical Mechanism (MCM3.3.1) reproduced the observed OH concentrations well but over-predicted the observed HO2 under low concentrations of NO (< 1ppbv) and under-predicted RO2 (both the complex RO2 fraction and other RO2 types which we classify as simple RO2) most significantly at the highest NO concentrations. The model also under-predicted the observed k.OH/consistently by 10s-1 across all NOx levels, highlighting that the good agreement for OH was fortuitous due to a cancellation of missing OH source and sink terms in its budget. Including heterogeneous loss of HO2 to aerosol surfaces did reduce the modelled HO2 concentrations in line with the observations but only at NO mixing ratios < 0:3ppbv. The inclusion of Cl atoms, formed from the photolysis of nitryl chloride, enhanced the modelled RO2 concentration on several mornings when the Cl atom concentration was calculated to exceed 1 × 104 atoms cm-3 and could reconcile the modelled and measured RO2 concentrations at these times. However, on other mornings, when the Cl atom concentration was lower, large under-predictions in total RO2 remained. Furthermore, the inclusion of Cl atom chemistry did not enhance the modelled RO2 beyond the first few hours after sunrise and so was unable to resolve the modelled under-prediction in RO2 observed at other times of the day. Model scenarios, in which missing VOC reactivity was included as an additional reaction that converted OH to RO2, highlighted that the modelled OH, HO2 and RO2 concentrations were sensitive to the choice of RO2 product. The level of modelled to measured agreement for HO2 and RO2 (both complex and simple) could be improved if the missing OH reactivity formed a larger RO2 species that was able to undergo reaction with NO, followed by isomerisation reactions reforming other RO2 species, before eventually generating HO2. In this work an a-pinene-derived RO2 species was used as an example. In this simulation, consistent with the experimental budget analysis, the model underestimated the observed OH, indicating a missing OH source. The model uncertainty, with regards to the types of RO2 species present and the radicals they form upon reaction with NO (HO2 directly or another RO2 species), leads to over an order of magnitude less O3 production calculated from the predicted peroxy radicals than calculated from the observed peroxy radicals at the highest NO concentrations. This demonstrates the rate at which the larger RO2 species propagate to HO2, to another RO2 or indeed to OH needs to be understood to accurately simulate the rate of ozone production in environments such as Beijing, where large multifunctional VOCs are likely present

Impact of HO2 aerosol uptake on radical levels and O3 production during summertime in Beijing

The impact of heterogeneous uptake of HO2 on aerosol surfaces on radical concentrations and the O3 production regime in Beijing in summertime was investigated. The uptake coefficient of HO2 onto aerosol surfaces, γHO2 , was calculated for the AIRPRO campaign in Beijing, in summer 2017, as a function of measured aerosol soluble copper concentration, [Cu2+]eff, aerosol liquid water content, [ALWC], and particulate matter concentration, [PM]. An average γHO2 across the entire campaign of 0.070 ± 0.035 was calculated, with values ranging from 0.002 to 0.15, and found to be significantly lower than the value of γHO2 = 0.2, commonly used in modelling studies. Using the calculated γHO2 values for the summer AIRPRO campaign, OH, HO2 and RO2 radical concentrations were modelled using a box model incorporating the Master Chemical Mechanism (v3.3.1), with and without the addition of γHO2 , and compared to the measured radical concentrations. The rate of destruction analysis showed the dominant HO2 loss pathway to be HO2 + NO for all NO concentrations across the summer Beijing campaign, with HO2 uptake contributing < 0.3 % to the total loss of HO2 on average. This result for Beijing summertime would suggest that under most conditions encountered, HO2 uptake onto aerosol surfaces is not important to consider when investigating increasing O3 production with decreasing [PM] across the North China Plain. At low [NO], however, i.e. < 0.1 ppb, which was often encountered in the afternoons, up to 29 % of modelled HO2 loss was due to HO2 uptake on aerosols when calculated γHO2 was included, even with the much lower γHO2 values compared to γHO2 = 0.2, a result which agrees with the aerosol-inhibited O3 regime recently proposed by Ivatt et al. (2022). As such it can be concluded that in cleaner environments, away from polluted urban centres where HO2 loss chemistry is not dominated by NO but where aerosol surface area is high still, changes in PM concentration and hence aerosol surface area could still have a significant effect on both overall HO2 concentration and the O3 production regime. Using modelled radical concentrations, the absolute O3 sensitivity to NOx and volatile organic compounds (VOCs) showed that, on average across the summer AIRPRO campaign, the O3 production regime remained VOC-limited, with the exception of a few days in the afternoon when the NO mixing ratio dropped low enough for the O3 regime to shift towards being NOx -limited. The O3 sensitivity to VOCs, the dominant regime during the summer AIRPRO campaign, was observed to decrease and shift towards a NOx -sensitive regime both when NO mixing ratio decreased and with the addition of aerosol uptake. This suggests that if [NOx ] continues to decrease in the future, ozone reduction policies focussing solely on NOx reductions may not be as efficient as expected if [PM] and, hence, HO2 uptake to aerosol surfaces continue to decrease. The addition of aerosol uptake into the model, for both the γHO2 calculated from measured data and when using a fixed value of γHO2 = 0.2, did not have a significant effect on the overall O3 production regime across the campaign. While not important for this campaign, aerosol uptake could be important for areas of lower NO concentration that are already in a NOx -sensitive regime