The formation of secondary organic aerosols (SOAs) combined with the partitioning of semivolatile organic components can impact numerous aerosol properties including cloud condensation nuclei (CCN) ...activity, hygroscopicity, and volatility. During the summer 2013 Southern Oxidant and Aerosol Study (SOAS) field campaign in a rural site in the southeastern United States, a suite of instruments including a CCN counter, a thermodenuder (TD), and a high-resolution time-of-flight aerosol mass spectrometer (AMS) were used to measure CCN activity, aerosol volatility, composition, and oxidation state. Particles were either sampled directly from ambient or through a particle-into-liquid sampler (PILS), allowing the investigation of the water-soluble aerosol component. Ambient aerosols exhibited size-dependent composition with larger particles being more hygroscopic. The hygroscopicity of thermally denuded aerosols was similar between ambient and PILS-generated aerosols and showed limited dependence on volatilization. Results of AMS three-factor positive matrix factorization (PMF) analysis for the PILS-generated aerosols showed that the most hygroscopic components are most likely the most and the least volatile features of the aerosols. No clear relationship was found between organic hygroscopicity and the oxygen-to-carbon ratio; in fact, isoprene-derived organic aerosols (isoprene-OAs) were found to be the most hygroscopic factor, while at the same time being the least oxidized and likely most volatile of all PMF factors. Considering the diurnal variation of each PMF factor and its associated hygroscopicity, isoprene-OA and more-oxidized oxygenated organic aerosols are the prime contributors to hygroscopicity and co-vary with less-oxidized oxygenated organic aerosols in a way that induces the observed diurnal invariance in total organic hygroscopicity. Biomass burning organic aerosols contributed little to aerosol hygroscopicity, which is expected since there was little biomass burning activity during the sampling period examined.
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•HI/R injury significantly decreased the expression level of miR-142-3p.•miR-142-3p alleviated apoptosis and inflammation to relieve HI/R injury.•miR-142-3p directly targeted ...MARCKS.•MARCKS siRNA markedly inhibited HI/R injury.
MiR-142-3p as one key molecule in oncogenesis and inflammation plays crucial roles in hepatic fibrosis, hepatocellular carcinoma and other liver disease. However, there have no literatures to report its effects on hepatic ischemia-reperfusion (HI/R) injury. In the present work, hypoxia reoxygenation (H/R) models on AML12 and HepG2 cells, and ischemia/reperfusion model in mice were established. The methods of real-time PCR, dual luciferase reporter, mimic, inhibitor, agomir, antagomir and siRNA transfection assays were used. The expression levels of miR-142-3p were decreased in model groups in vitro and in vivo compared with control group or Sham group, which directly targeted MARCKS to regulate its expression. Then, MARCKS activated p38/JNK signal, up-regulated NF-κB expression to accelerate inflammation, and inhibited PI3K/AKT signal to promote apoptosis. Moreover, miR-142-3p mimic in vitro and agomir in vivo lowered the expression levels of MARCKS, thereby alleviating apoptosis and inflammation to relieve HI/R injury. Furthermore, miR-142- 3p inhibitor in vitro and antagomir in vivo up-regulated the expression levels of MARCKS to aggravate HI/R damage via promoting inflammation and apoptosis. Consistently, MARCKS siRNA markedly inhibited HI/R injury by restraining apoptosis and inflamm- ation in mice. MiR-142-3p played a considerable part in adjusting HI/R injury by targeting MARCKS, and miR-142-3p/MARCKS should be a new therapeutic target for HI/R injury.
Light is considered the most important environmental factor for greenhouse crops, and lack of lighting limits the productivity of greenhouses. Many studies have focused on improving the energy ...efficiency of lighting in agriculture. In this study, LED lights were mounted in the top, middle and bottom of the plant canopy to provide additional photosynthetically active radiation. Assuming that 100% of the predicted outdoor radiation is available, the canopy light distribution model was used to determine the relationship between the light energy consumption and the optimal yield. Decision-making on lighting scheduling may be considered as a constrained optimisation, and the status of the LEDs in a period acts as the decision variable. Besides, there are two objective functions: one is the energy consumed by the LED device; the other is the expected yield calculated by the crop model of tomatoes. The optimal solution of the multi-objective optimisation is not unique but corresponds to an infinite number of yield/energy combinations. Farmers can select these combinations according to additional restrictions such as energy efficiency ratio or photoperiod. The yield of our strategy was increased by 12.3% under the constraint of equal energy consumption compared to the greenhouse threshold control strategy. Given the same output as the constraint, the energy consumption was reduced by 30.1%.
Aim
To explore the mechanism of secreted frizzled‐related protein I (sFRP1) involvement in the osteogenic differentiation of human periodontal ligament cells (hPDLCs) under inflammatory conditions.
...Methodology
hPDLCs were cultured in an osteogenic differentiation‐inducing medium (odi) and subjected to the stimulation of Porphyromonas gingivalis lipopolysaccharide (P. gingivalis LPS) with or without the inhibition of sFRP1. Quantitative real‐time polymerase chain reaction, Western blot and enzyme‐linked immunosorbent assay were carried out to evaluate the expression of osteogenic markers as well as the classic Wnt signalling pathway. Periapical periodontitis was induced in Wistar rats to further confirm the effect of sFRP1 inhibitor on bone loss in vivo. After the Shapiro–Wilk normality test, data were analysed by Student’s paired t‐test or one‐way Anova test with a P value less than 0.05 as the level of statistical significance.
Results
Significantly decreased mRNA and protein expression of osteogenic markers were detected in hPDLCs treated with P. gingivalis LPS during osteogenic induction (P < 0.001). Increased expression of sFRP1 was observed (P < 0.01), whilst Wnt/β‐catenin signalling pathway was inhibited by the addition of P. gingivalis LPS (P < 0.01). After the addition of the sFRP1 inhibitor, the decrease of osteogenic markers (P < 0.05) and the inhibition of Wnt/β‐catenin signalling pathway (P < 0.05) were reversed significantly. The animal experiment further confirmed that the sFRP1 inhibitor significantly reduced bone loss of periapical lesions in vivo (P < 0.0001).
Conclusions
Wnt antagonist sFRP1 was involved in the osteogenic differentiation of hPDLCs under inflammation. Modulation of the Wnt/β‐catenin signalling pathway through the inhibition of sFRP1 may offer a new perspective on the treatment of chronic apical periodontitis.
As an active constituent of the beetle Mylabris used in traditional Chinese medicine, cantharidin is a potent and selective inhibitor of protein phosphatase 2A (PP2A) that plays a crucial role in ...cell cycle progression, apoptosis, and cell fate. The role and possible mechanisms exerted by cantharidin in cell growth and metastasis of breast cancer were investigated in this study. Cantharidin was found to inhibit cell viability and clonogenic potential in a time- and dose-dependent manner. Cell cycle analysis revealed that cell percentage in G2/M phase decreased, whereas cells in S and G1 phases progressively accumulated with the increasing doses of cantharidin treatment. In a xenograft model of breast cancer, cantharidin inhibited tumor growth in a dose-dependent manner. Moreover, high doses of cantharidin treatment inhibited cell migration in wound and healing assay and downregulated protein levels of major matrix metalloproteinases (MMP)-2 and MMP-9. MDA-MB-231 cell migration and invasion were dose-dependently inhibited by cantharidin treatment. Interestingly, the members of the mitogen-activated protein kinase (MAPK) signaling family were less phosphorylated as the cantharidin dose increased. Cantharidin was hypothesized to exert its anticancer effect through the MAPK signaling pathway. The data of this study also highlighted the possibility of using PP2A as a therapeutic target for breast cancer treatment.
We examine the formation of nitrate and ammonium on five types of externally mixed pre-existing aerosols using the hybrid dynamic method in a global chemistry transport model. The model developed ...here predicts a similar spatial pattern of total aerosol nitrate and ammonium to that of several pioneering studies, but separates the effects of nitrate and ammonium on pure sulfate, biomass burning, fossil fuel, dust and sea salt aerosols. Nitrate and ammonium boost the scattering efficiency of sulfate and organic matter but lower the extinction of sea salt particles since the hygroscopicity of a mixed nitrate-ammonium-sea salt particle is less than that of pure sea salt. The direct anthropogenic forcing of particulate nitrate and ammonium at the top of the atmosphere (TOA) is estimated to be −0.12 W m−2. Nitrate, ammonium and nitric acid gas also affect aerosol activation and the reflectivity of clouds. The first aerosol indirect forcing by anthropogenic nitrate (gas plus aerosol) and ammonium is estimated to be −0.09 W m−2 at the TOA, almost all of which is due to condensation of nitric acid gas onto growing droplets (−0.08 W m−2).
Among the current CO2 capture technologies, membrane gas separation has many inherent advantages over other conventional techniques. However, fabricating gas separation membranes with both high CO2 ...permeance and high CO2/N2 selectivity, especially under wet conditions, is a challenge. In this study, sub-20-nm thick, layered graphene oxide (GO)-based hollow fiber membranes with grafted, brush-like CO2-philic agent alternating between GO layers are prepared by a facile coating process for highly efficient CO2/N2 separation under wet conditions. Piperazine, as an effective CO2-philic agent, is introduced as a carrier-brush into the GO nanochannels with chemical bonding. The membrane exhibits excellent separation performance under simulated flue gas conditions with CO2 permeance of 1,020 GPU and CO2/N2 selectivity as high as 680, demonstrating its potential for CO2 capture from flue gas. We expect this GO-based membrane structure combined with the facile coating process to facilitate the development of ultrathin GO-based membranes for CO2 capture.
Hydroponics experiments were conducted to study the effects of sodium nitroprusside (SNP, a donor of NO) on lead toxicity in ryegrass (Lolium perenne L.) seedlings. When the ryegrass seedlings were ...grown in a nutrient solution containing 500 μM Pb²⁺for two weeks, the plant biomass as well as net photosynthetic rate, transpiration rate, chlorophyll and carotenoid content of leaves decreased. The Pb stress also induced the production of superoxide anion (O₂·⁻) and hydrogen peroxide (H₂O₂), leading to malondialdehyde (MDA) accumulation. Furthermore, the activities of superoxide dismutase (SOD), peroxidase (POD), and ascorbate peroxidase (APX) decreased in the Pb-treated seedlings, but the catalase (CAT) activity increased. Additionally, the content of Cu in shoots and the content of K, Mg, Fe, and Zn in both shoots and roots decreased, but the content of Ca in shoots and roots increased under the Pb stress. Moreover, Pb accumulated mostly in roots, whereas a small quantity was translocated to shoots. However, the addition of 50, 100, and 200 μM SNP into the solution containing Pb increased the chlorophyll content and net photosynthetic rate, reduced Pb-induced oxidative damages, improved antioxidant enzyme activities, and inhibited translocation of Pb from roots to shoots. In particular, 100 μM SNP had the best effect on promoting growth of the ryegrass seedlings under the Pb toxicity. However, the application of 400 μM SNP had no obvious alleviating effect on Pb toxicity in the ryegrass seedlings.
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