Association between the mean perfusion pressure and the risk of acute kidney injury in critically ill patients with sepsis: a retrospective cohort study.

BACKGROUND: Mean perfusion pressure (MPP) has recently emerged as a potential biomarker for personalized management of tissue perfusion in critically ill patients. However, its association with the occurrence of acute kidney injury (AKI) in septic patients and the optimal MPP range remain uncertain. Therefore, this study aims to investigate the relationship between MPP and AKI in critically ill patients with sepsis. METHODS: We identified 5867 patients with sepsis from the MIMIC-IV database who met the inclusion and exclusion criteria. The exposure variable was the first set of MPP measured within 24 h after ICU admission with invasive hemodynamic monitoring. The primary outcome was the incidence of AKI at 7 days following ICU admission according to the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines. Secondary outcomes included in-hospital mortality, lengths of ICU, and hospital stay. Optimal cut-off point for MPP were determined using the Youden index, and multivariable logistic regression was employed to examine the association between MPP and AKI. Subgroup analyses were conducted to enhance result robustness. Kaplan-Meier survival analysis was utilized to evaluate in-hospital mortality rates categorized by MPP. RESULTS: A total of 5,867 patients with sepsis were included in this study, and the overall incidence of AKI was 82.3%(4828/5867). Patients were categorized into low MPP (< 63 mmHg) and high MPP (≥ 63 mmHg) groups using the optimal ROC curve-derived cut-off point. The incidence of AKI in the low MPP group was higher than that in the high MPP group (87.6% vs. 78.3%, P < 0.001). Multivariable logistic regression analysis adjusted for confounding factors revealed that each 1 mmHg increase in MPP as a continuous variable was associated with a 2% decrease in AKI incidence within 7 days of ICU admission (OR:0.98, 95%CI:0.97-0.99, P < 0.001). When MPP was used as a categorical variable, patients in the high MPP group had a lower risk of AKI than those in the low MPP group (OR:0.71, 95%CI:0.61-0.83, P = 0.001). Subgroup analyses demonstrated a consistent association between MPP and AKI risk across all variables assessed (P for interaction all > 0.05). Kaplan-Meier curve analysis demonstrated a higher survival rate during hospitalization in the high MPP group compared to the low MPP group (Log-rank test, P < 0.0001). CONCLUSIONS: Lower levels of MPP are associated with an increased incidence of AKI at 7 days in critically ill patients with sepsis.

[Multi-omics analysis of regulating effects of hyperoside on lipid metabolism in high-fat diet mice].

The aim of this study was to explore the regulating effects of hyperoside (Hyp) on lipid metabolism in high-fat diet mice. The high-fat diet mouse model was established by high-fat diet induction. After 5 weeks of Hyp intragastric administration in high-fat diet mice, the serum lipid levels before and after Hyp administration were measured by the corresponding kits. The tissue structure of mouse liver was observed by HE staining before and after Hyp administration. The changes of intestinal flora and transcriptome were measured by Illumina platforms. Liquid chromatography-mass spectrometry (LC-MS) was used to determine non-targeted metabolites. The results showed that Hyp significantly reduced lipid levels in the high-fat diet mice and effectively restored the external morphology and internal structure of liver tissue. Hyp changed the species composition of the intestinal flora in high-fat diet mice, increased the abundance of beneficial flora such as Ruminococcus, and decreased the abundance of harmful flora such as Sutterella. Combined multi-omics analysis revealed that the effect of retinoic acid on lipid metabolism was significant in the high-fat diet mice treated with Hyp, while the increase of retinoic acid content was significantly negatively correlated with the expression of genes such as cyp1a2 and ugt1a6b, positively correlated with AF12 abundance, and significantly negatively correlated with unidentified_Desulfovibrionaceae abundance. These results suggest that Hyp may modulate the abundance of AF12, unidentified_Desulfovibrionaceae and inhibit the expression of genes such as cyp1a2 and ugt1a6b, thus increasing the content of retinoic acid and regulating lipid metabolism in the high-fat diet mice.

Seasonal variations, temperature dependence, and sources of size-resolved PM components in Nanjing, east China.

Size-segregated ambient particulate matter (PM) samples were collected seasonally in suburban Nanjing of east China from 2016 to 2017 and chemically speciated. In both fine (< 2.1 µm, PM2.1) and coarse (> 2.1 µm, PM>2.1) PM, organic carbon (OC) accounted for the highest fractions (26.9% ± 10.9% and 23.1% ± 9.35%) of all measured species, and NO3- lead in average concentrations of water-soluble inorganic ions (WSIIs). The size distributions of measured components were parameterized using geometric mean diameter (GMD). GMD values of NO3-, Cl-, OC, and PM for the whole size range varied from < 2.1 µm in winter to > 2.1 µm in warm seasons, which was due to the fact that the size distributions of semi-volatile components (e.g., NH4NO3, NH4Cl, and OC) had a dependency on the ambient temperature. Unlike OC, elemental carbon (EC), and elements, NH4+, NO3-, and SO42- exhibited an increase trend in GMD values with relative humidity, indicating that the hygroscopic growth might also play a role in driving seasonal changes of PM size distributions. Positive matrix factorization was performed using compositional data of fine and coarse particles, respectively. The secondary formation of inorganic salts contributing to the majority (> 70%) of fine PM and 20.2% ± 19.9% of speciated coarse PM. The remaining coarse PM content was attributed to a variety of dust sources. Considering that coarse and fine PM had comparable mass concentrations, more attention should be paid to local dust emissions in future air quality plans.

Neddylation inhibitor MLN4924 has anti-HBV activity via modulating the ERK-HNF1α-C/EBPα-HNF4α axis.

Hepatitis B virus (HBV) infection is a major public health problem. The high levels of HBV DNA and HBsAg are positively associated with the development of secondary liver diseases, including hepatocellular carcinoma (HCC). Current treatment with nucleos(t)ide analogues mainly reduces viral DNA, but has minimal, if any, inhibitory effect on the viral antigen. Although IFN reduces both HBV DNA and HBsAg, the serious associated side effects limit its use in clinic. Thus, there is an urgent demanding for novel anti-HBV therapy. In our study, viral parameters were determined in the supernatant of HepG2.2.15 cells, HBV-expressing Huh7 and HepG2 cells which transfected with HBV plasmids and in the serum of HBV mouse models with hydrodynamic injection of pAAV-HBV1.2 plasmid. RT-qPCR and Southern blot were performed to detect 35kb mRNA and cccDNA. RT-qPCR, Luciferase assay and Western blot were used to determine anti-HBV effects of MLN4924 and the underlying mechanisms. We found that treatment with MLN4924, the first-in-class neddylation inhibitor currently in several phase II clinical trials for anti-cancer application, effectively suppressed production of HBV DNA, HBsAg, 3.5kb HBV RNA as well as cccDNA. Mechanistically, MLN4924 blocks cullin neddylation and activates ERK to suppress the expression of several transcription factors required for HBV replication, including HNF1α, C/EBPα and HNF4α, leading to an effective blockage in the production of cccDNA and HBV antigen. Our study revealed that neddylation inhibitor MLN4924 has impressive anti-HBV activity by inhibiting HBV replication, thus providing sound rationale for future MLN4924 clinical trial as a novel anti-HBV therapy.

Estimating the contribution of atmosphere on heavy metals accumulation in the aboveground wheat tissues induced by anthropogenic forcing.

The influence of atmosphere pollution on human health is receiving more and more concerns as strengthened anthropogenic activity had brought excessive pollutant into the atmosphere. To date, the quantitative estimation about the contribution of atmosphere on the accumulation of heavy metal in the edible cereal parts induced by anthropogenic forcing is scarce. Taking the Yangtze River Delta area, China as an example, this study estimates quantitatively the influence of atmosphere on the concentration of heavy metal in the aboveground wheat tissues induced by anthropogenic industrial activity at the regional scale. The results show that the aboveground wheat tissues in the southern Yangtze River Delta area accumulated much more heavy metals than that in the northern area, although there is no significant difference in the geological and climate conditions, soil types, agricultural manages, wheat cultivar and soil heavy metals concentrations (even heavy metals concentrations in wheat root) between the southern area and northern area. The mean concentrations of Pb, Zn, Cu and Cd in wheat grain in southern area have exceeded the thresholds of contamination levels. The present study suggests that the influence of atmosphere on the accumulation of Hg, Cd, Pb, Zn, Cu, Ni and Cr in the aboveground wheat tissues is greatly significant when high amounts of pollutant are measured in the atmosphere. Based on translocation coefficient of the element, it is estimated that atmospheric pollution induced by anthropogenic forcing might lead to the concentration of heavy metals in wheat straw and grain increase by approximately 100% and 354% (Hg), 64% and 293% (Pb), 122% and 160% (Cr), 50% and 38% (Cd) and 14% and 41% (Cu), respectively.

[Molecular mechanisms of anti-inflammatory action of AMPK].

AMP-activated protein kinase (AMPK), an evolutionarily conserved serine/threonine protein kinase, is known as the "cellular energy regulator" and a key molecule to maintain the energy balance of cells and organism. Recent studies have shown that AMPK exerts anti-inflammatory effects mainly through activating SIRT1, PGC-1α, p53, FoxO3a and p300, and down-regulating the activity of various inflammatory related proteins such as NF-κB and AP-1. This article reviews the molecular mechanisms of the anti- inflammatory effects of AMPK, and provides some clues for the development of AMPK-targeted therapeutics to treat inflammation and related diseases.

Light Absorption of Secondary Organic Aerosol: Composition and Contribution of Nitroaromatic Compounds.

Secondary organic aerosol (SOA) can affect the atmospheric radiation balance through absorbing light at shorter visible and UV wavelengths. However, the composition and optical properties of light-absorbing SOA is poorly understood. In this work, SOA filter samples were collected during individual chamber experiments conducted with three biogenic and eight aromatic volatile organic compound (VOC) precursors in the presence of NOX and H2O2. Compared with the SOA generated using the aromatic precursors, biogenic SOA generally exhibits negligible light absorption above 350 nm; the aromatic SOA generated in the presence of NOX shows stronger light absorption than that generated with H2O2. Fifteen nitroaromatic compound (NAC) chemical formulas were identified and quantified in SOA samples. Their contributions to the light absorption of sample extracts were also estimated. On average, the m-cresol/NOX SOA sample has the highest mass contribution from NACs (10.4 ± 6.74%, w/w), followed by naphthalene/NOX (6.41 ± 2.08%) and benzene/NOX (5.81 ± 3.82%) SOA. The average contributions of NACs to total light absorption were at least two times greater than their average mass contributions at 365 and 400 nm, revealing the potential use of chromophoric NACs as brown carbon (BrC) tracers in source apportionment and air quality modeling studies.

Inhibitory effect of luteolin on the proliferation of human breast cancer cell lines induced by epidermal growth factor.

The aim of the present study was to investigate the mechanism of the inhibitory effect of luteolin on the proliferation of breast cancer cells induced by epidermal growth factor (EGF) in vitro. MTT assay was used to detect the inhibitory effect of luteolin on the proliferation of MCF-7 and MDA-MB-231 cells as well as the effect on the proliferation of MCF-7 cells induced by EGF. Western blotting was used to detect the effects of luteolin on the expression of epidermal growth factor receptor (EGFR), phosphatidylinositol 3-kinase (PI3K)/Akt, mitogen-activated protein kinase (MAPK)/extracellular-signal-regulated kinases (Erk) 1/2 and signal transducers and activators of transcription-3 (STAT3) in MCF-7 cells induced by EGF. The results showed that luteolin could significantly inhibit the proliferation of MCF-7 and MDA-MB-231 cells, and the inhibitory effect on MCF-7 cells was more prominent. Moreover, luteolin could inhibit the proliferation of MCF-7 cells induced by EGF. Western blotting results showed that luteolin and AG1478 (an inhibitor of EGFR signaling) could inhibit the expression of p-EGFR and p-STAT3 in MCF-7 cells induced by EGF. Luteolin, LY294002 (an inhibitor of Akt signaling) and PD98059 (an inhibitor of Erk1/2 signaling) could inhibit the expression of p-Akt and p-Erk1/2 respectively in MCF-7 cells induced by EGF. Our data suggest that luteolin may inhibit EGF-induced activities of EGFR signaling pathway in human breast cancer cell lines, and PI3K/Akt, MAPK/Erk1/2, STAT3 signal pathways may be the major pathways that mediate the inhibitory effect of luteolin on EGFR signaling. Overall, our results may provide a theoretical foundation for the development of luteolin as anti-tumor drug.

[Inhibition of methicillin-resistant Staphylococcus aureus biofilm by honokiol].

Objective: To study the inhibition of methicillin-resistant Staphylococcus aureas (MRSA) biofilm by honokiol. Methods: We used triphenyl tetrazolium chloride method to evaluate the inhibition of biofilm formation and mature by honokiol. We used congo red agar and spectrophotometer to detect the influence of honokiol on polysaccharide intercellular adhesion formation and extracellular DNA release. RT-PCR analysis was used to determine the effect of honokiol on expression of icaA, cidA and agrA. Results: Honokiol showed strong antimicrobial activity both on biofilm formation and mature biofilm of MRSA 41573. Minimum inhibitory concentration was 10 µg/mL for biofilm formation and 50 µg/mL for mature biofilm. Minimum bactericidal concentration was 20 µg/mL for biofilm formation and 100 µg/mL for mature biofilm. Honokiol showed synergy effect with vancomycin and it significantly increased the sensitivity of mature biofilm to vancomycin. Polysaccharide intercellular adhesion formation and extracellular DNA release were effectively inhibited by honokiol. Extracellular DNA release decreased by 28.3% when honokiol at 1/8 MIC. After incubated with 1/2 MIC of honokiol for 16 h, the relative expression of icaA, cidA and agrA of MRSA41573 was reduced by 59.1%, 56% and 72.3%, respectively. Conclusion: Honokiol can significantly inhibit biofilm formation of MRSA41573 and its mechanism is mainly the inhibited expression of icaA and cidA to influence the synthesis of polysaccharide intercellular adhesion and extracellular DNA. Moreover, it also affect biofilm formation by QS system.

[Progress in gene regulation mechanisms of Staphylococcus biofilm development--A review].

Bacterial resistance is a threat to public health. Bacterial biofilm formation is one of the main reasons for persistent infection caused by bacteria. Biofilm development is a complex process that involves many factors and genes which play various roles in all stages of the biofilm formation. This review focuses on the gene regulatory mechanisms relate to the biofilm formation of Staphylococcus, the most common pathogen that causes nosocomial infection, as well as the latest developments of pharmacological anti-biofilm therapies. We also address new strategy to treat bacterial infection and the development of drugs and vaccines against biofilm resistance.

Gas/particle partitioning of 2-methyltetrols and levoglucosan at an urban site in Denver.

In this study, a medium volume sampler incorporating quartz fiber filters (QFFs) and a polyurethane foam (PUF)/XAD/PUF sandwich (PXP) was used to collect 2-methyltetrols (isoprene tracer) and levoglucosan (biomass burning tracer) in gaseous and particle (PM2.5) phases. The measured gas/particle (G/P) partitioning coefficients (Kp,OMm) of 2-methyltetrols and levoglucosan were calculated and compared to their predicted G/P partitioning coefficients (Kp,OMt) based on an absorptive partitioning theory. The breakthrough experiments showed that gas-phase 2-methyltetrols and levoglucosan could be collected using the PXP or PUF adsorbent alone, with low breakthrough; however, the recoveries of levoglucosan in PXP samples were lower than 70% (average of 51.9­63.3%). The concentration ratios of 2-methyltetrols and levoglucosan in the gas phase to those in the particle phase were often close to or higher than unity in summer, indicating that these polar species are semi-volatile and their G/P partitioning should be considered when applying particle-phase data for source apportionment. The Kp,OMm values of 2-methyltetrols had small variability in summer Denver, which was ascribed to large variations in concentrations of particulate organic matter (5.14 ± 3.29 µg m­3) and small changes in ambient temperature (21.8 ± 4.05 °C). The regression between log Kp,OMm and log Kp,OMt suggested that the absorptive G/P partitioning theory could reasonably predict the measured G/P partitioning of levoglucosan in ambient samples.

Impact of gas/particle partitioning of semivolatile organic compounds on source apportionment with positive matrix factorization.

To quantify and minimize the influence of gas/particle (G/P) partitioning on receptor-based source apportionment using particle-phase semivolatile organic compound (SVOC) data, positive matrix factorization (PMF) coupled with a bootstrap technique was applied to three data sets mainly composed of "measured-total" (measured particle- + gas-phase), "particle-only" (measured particle-phase) and "predicted-total" (measured particle-phase + predicted gas-phase) SVOCs to apportion carbonaceous aerosols. Particle- (PM2.5) and gas-phase SVOCs were collected using quartz fiber filters followed by PUF/XAD-4/PUF adsorbents and measured using gas chromatography-mass spectrometry (GC-MS). Concentrations of gas-phase SVOCs were also predicted from their particle-phase concentrations using absorptive partitioning theory. Five factors were resolved for each data set, and the factor profiles were generally consistent across the three PMF solutions. Using a previous source apportionment study at the same receptor site, those five factors were linked to summertime biogenic emissions (odd n-alkane factor), unburned fossil fuels (light SVOC factor), road dust and/or cooking (n-alkane factor), motor vehicle emissions (PAH factor), and lubricating oil combustion (sterane factor). The "measured-total" solution was least influenced by G/P partitioning and used as reference. Two out of the five factors (odd n-alkane and PAH factors) exhibited consistent contributions for "particle-only" vs "measured-total" and "predicted-total" vs "measured-total" solutions. Factor contributions of light SVOC and n-alkane factors were more consistent for "predicted-total" vs "measured-total" than "particle-only" vs "measured-total" solutions. The remaining factor (sterane factor) underestimated the contribution by around 50% from both "particle-only" and "predicted-total" solutions. The results of this study confirm that when measured gas-phase SVOCs are not available, "predicted-total" SVOCs should be used to decrease the influence of G/P partitioning on receptor-based source apportionment.

PEAKS DB: de novo sequencing assisted database search for sensitive and accurate peptide identification.

Many software tools have been developed for the automated identification of peptides from tandem mass spectra. The accuracy and sensitivity of the identification software via database search are critical for successful proteomics experiments. A new database search tool, PEAKS DB, has been developed by incorporating the de novo sequencing results into the database search. PEAKS DB achieves significantly improved accuracy and sensitivity over two other commonly used software packages. Additionally, a new result validation method, decoy fusion, has been introduced to solve the issue of overconfidence that exists in the conventional target decoy method for certain types of peptide identification software.

[Inhibitory effects of biochanin A on the efflux pump of methicillin-resistant Staphylococcus aureus (MRSA)].

OBJECTIVE: To study the inhibitory effect of biochanin A on efflux system of Methicillin-resistant Staphylococcus aureus (MRSA). METHODS: Inhibitory effects of biochanin A on efflux system of Strain MRSA41577 were evaluated using double dilution method, two plate method and fluorescence spectrophotometry. Real time PCR and SDS-PAGE were applied to detect the expression of MRSA41577 norA and to analyze the changes of MRSA41577 efflux protein before and after dosing biochanin A in association with liquid chromatography mass spectrometry to determinate protein variation. RESULTS: Biochanin A alone had no inhibitory effect on MRSA41577, but it showed synergy effect with ciprofloxacin in inhibition MRSA41577 in which 40pg/mL biochanin A decreased the minimum inhibitory concentration (MIC) value of ciprofloxacin from 64 microg/mL to 8 microgg/mL. Biochanin A significantly increased the accumulation of ciprofloxacin in MRSA41577 in a time-dependent manner. At 15 min, biochanin A increased ciprofloxacin in MRSA41577 by 83%, which is similar to that of reserpine (positive control). Further mechanism studies indicated that biochanin A could reduce the expression of nor A in ciprofloxacin-treated MRSA41577. After incubated with biochanin A and ciprofloxacin for 16 h, the relative expression of nor A of MRSA41577 was reduced by 65%. SDS-PAGE analysis showed that the total protein profiles of MRSA41577 were significantly changed after treatment with biochanin A for 16h, in which both norA protein and efflux system ABC transporter ATP-binding protein were significantly decreased. CONCLUSION: Biochanin A could inhibit Methicillin-resistant Staphylococcus aureus efflux system through reducing pathogen' s expression of nor A and norA protein.

[Differences of Three Methods in Determining Ozone Sensitivity in Nanjing].

In recent years， ozone （O3） has become an increasingly important air pollutant in China. Identifying the sensitivity of O3 to the precursors volatile organic compounds （VOCs） and nitrogen oxides （NOx） can help make effective abatement strategies. This study compared three methods for determining O3-VOCs-NOx sensitivity： simulated photochemical indicator values and sensitivity coefficients derived from a three-dimensional air quality model and an observation-based model （OBM）， with a case study involving an O3 pollution event that occurred in Nanjing in late July 2017. The results showed that O3 sensitivity based on the photochemical indicator and sensitivity coefficients demonstrated similar spatial variations （over 50% of the grid cells of Nanjing exhibiting identical O3 sensitivity）. However， sensitivity coefficients identified a larger number of areas within a transitional O3 sensitivity regime， as opposed to the VOCs- or NOx-limited regime identified by the photochemical indicator. The determination of the latter was affected by the adopted threshold values. The OBM relied on the quality of the observational data. For example， positive biases in observed NO2 could lead to an underestimation of O3 sensitivity to NOx with the OBM. During the high pollution period， the three methods exhibited significant disparities. The photochemical indicator tended to suggest the VOCs-limited condition， whereas the OBM and sensitivity coefficients indicated the NOx-limited or transitional regimes.

Degradation of the emerging brominated flame retardant tetrabromobisphenol S using organo-montmorillonite supported nanoscale zero-valent iron.

The widespread occurrence of emerging brominated flame retardant tetrabromobisphenol S (TBBPS) has become a major environmental concern. In this study, a nanoscale zero-valent iron (nZVI) impregnated organic montmorillonite composite (nZVI-OMT) was successfully prepared and utilized to degrade TBBPS in aqueous solution. The results show that the nZVI-OMT composite was very stable and reusable as the nZVI was well dispersed on the organic montmorillonite. Organic montmorillonite clay layers provide a strong support, facilitate well dispersion of the nZVI chains, and accelerate the overall TBBPS transformation with a degradation rate constant 5.5 times higher than that of the original nZVI. Four major intermediates, including tribromobisphenol S (tri-BBPS), dibromobisphenol S (di-BBPS), bromobisphenol S (BBPS), and bisphenol S (BPS), were detected by high-resolution mass spectrometry (HRMS), indicating sequential reductive debromination of TBBPS mediated by nZVI-OMT. The effective elimination of acute ecotoxicity predicted by toxicity analysis also suggests that the debromination process is a safe and viable option for the treatment of TBBPS. Our results have shown for the first time that TBBPS can be rapidly degraded by an nZVI-OMT composite, expanding the potential use of clay-supported nZVI composites as an environmentally friendly material for wastewater treatment and groundwater remediation.

New insights into the influences of firework combustion on molecular composition and formation of sulfur- and halogen-containing organic compounds.

Firework (FW) events occur during various festivals worldwide and substantially negatively influence both air quality and human health. However, the effects of FWs on the chemical properties and formation of organic aerosols are far from clear. In this study, fine particulate matter (PM2.5) samples were collected in a suburban area in Qingdao, China during the Chinese Spring Festival. The concentrations of chemical species (especially carbonaceous components) in PM2.5 were measured using a combination of several state-of-the-art techniques. Our results showed that mass concentrations of water-soluble sulfate, potassium and chloride ions, and organic carbon drastically increased and became the predominant components in PM2.5 during FW events. Correspondingly, both the number and fractional contributions of sulfur (S)-containing subgroups (e.g., CHOS and CHONS compounds) and some chlorine (Cl)-containing organic (e.g., CHOSCl and CHONSCl) compounds identified using ultrahigh-resolution Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS) increased. The S- and Cl-containing compounds unique to the FW display period were identified, and their chemical characterization, sources, and formation mechanisms were elucidated by combining FT-ICR MS and quantum chemical calculations. Our results suggest that FW emissions play notable roles in both primary and secondary organic aerosol formation, especially for CHOS- and Cl-containing organic compounds.

Positive matrix factorization of a 32-month series of daily PM2.5 speciation data with incorporation of temperature stratification.

This study presents source apportionment results for PM2.5 from applying positive matrix factorization (PMF) to a 32-month series of daily PM2.5 compositional data from Denver, CO, including concentrations of sulfate, nitrate, bulk elemental carbon (EC) and organic carbon (OC), and 51 organic molecular markers (OMMs). An optimum 8-factor solution was determined primarily based on the interpretability of the PMF results and rate of matching factors from bootstrapped PMF solutions with those from the base case solution. These eight factors were identified as inorganic ion, n-alkane, EC/sterane, light n-alkane/polycyclic aromatic hydrocarbon (PAH), medium alkane/alkanoic acid, PAH, winter/methoxyphenol and summer/odd n-alkane. The inorganic ion factor dominated the reconstructed PM2.5 mass (sulfate + nitrate + EC + OC) in cold periods (daily average temperature < 10 °C; 43.7% of reconstructed PM2.5 mass) whereas the summer/odd n-alkane factor dominated in hot periods (> 20 °C; 53.1%). The two factors had comparable relative contributions of 26.5% and 27.1% in warm periods with temperatures between 10 °C and 20 °C. Each of the seven factors resolved in a previous study (Dutton et al., 2010b) using a 1-year data set from the same location matches one factor from the current work based on comparing factor profiles. Six out of the seven matched pairs of factors are linked to similar source classes as suggested by the strong correlations between factor contributions (r = 0.89 - 0.98). Temperature-stratified source apportionment was conducted for three subsets of the data in the current study, corresponding to the cold, warm and hot periods mentioned above. The cold period (7-factor) solution exhibited a similar distribution of reconstructed PM2.5 mass as the full data set solution. The factor contributions of the warm period (7-factor) solution were well correlated with those from the full data set solution (r = 0.76 - 0.99). However, the reconstructed PM2.5 mass was distributed more to inorganic ion, n-alkane and medium alkane/alkanoic acid factors in the warm period solution than in the full data set solution. For the hot period (6-factor) solution, PM2.5 mass distribution was quite different from that of the full data set solution, as illustrated by regression slopes as low as 0.2 and as high as 4.8 of each matched pair of factors across the two solutions.

[Relationship between the inhibitory effect of fraxetin on breast cancer and estrogen signaling pathway].

Estrogen signaling pathways play an important role in the regulation of the physiological function of breast cancer cell proliferation and apoptosis. The article used MTT assay, flow cytometer analysis and Western blot to detect the inhibition of fraxetin on MCF-7 cell cycle distribution and apoptosis, ERα, cyclin D1 and Bcl-2 expression levels, MAPK and PI3K signaling pathway to investigate the mechanism of anti-breast cancer of fraxetin. The results showed fraxetin inhibited E2ß-stimulated MCF-7 cell proliferation in a dose- and time-dependent manner, reversed E2ß-induced anti-apoptosis and promoted G0/G1 phase arrest. After treatment with fraxetin, the expression of ERα in MCF-7 cell was decreased, and estrogen genomic signaling pathway was inhibited by down-regulating the expression of cyclin D1 and Bcl-2 proteins. After MCF-7 cells were treated with fraxetin, the expressions of MAPK/Erk1/2 protein were reduced, which affected estrogen non-genomic signaling pathway. The results suggest fraxetin plays a part in anti-breast cancer function through E2ß-mediated genomic and non-genomic signaling pathways.

[Inhibitory effect of luteolin on the angiogenesis of chick chorioallantoic membrane and invasion of breast cancer cells via downregulation of AEG-1 and MMP-2].

The purpose of the present study was to investigate the effect of luteolin on the angiogenesis and invasion of breast cancer cells. MTT assay was used to examine breast cancer proliferation. The chick chorioallantoic membrane model was used to assess the angiogenesis effect. Wound healing assay was used to assess cell invasion ability. Western blot was used to analyze Bcl-2, AEG-1 and MMP-2 expression levels. The results showed luteolin inhibited MCF-7 cells proliferation in a dose- and time-dependent manner, and the expression of Bcl-2 protein was decreased. Luteolin had a strong anti-angiogenesis of chick chorioallantoic membrane. After treatment of MCF-7 cells with luteolin at 60 µmol/L for 48 h, migration rate was reduced by 71.07% compared with control (P < 0.01). After treatment of MCF-7 cells with luteolin at 60 µmol/L for 48 h, the expression of AEG-1 and MMP-2 was reduced by 82.34% (P < 0.05) and 85.70% (P < 0.05) respectively, compared with control. In conclusion, the results suggest that luteolin can inhibit the proliferation of breast cancer cells, and suppress the expression of Bcl-2. Furthermore, luteolin has strong anti-angiogenesis of chick chorioallantoic membrane and anti-invasive activity on breast cancer cells, and down-regulates the expression of AEG-1 and MMP-2.