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1.
Sci Total Environ ; 711: 134745, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31822400

RESUMO

In the Northern China Plain (NCP), extreme haze events with high concentrations of fine particles occur frequently during the winter but rarely occur in autumn. In this study, we present a synthetic analysis of particulate constituents during the historically polluted transition period of autumn-winter in 2018, revealing that mixed-type haze episodes are the result of regional transport, homogeneous/heterogeneous conversion, and sandstorm influences. The hydrolysis process of N2O5 at higher relative humidity levels (>70%), which feature an enhanced nitrate oxidation ratio (0.30-0.70) and NO3- concentration (>60 µg m-3), was the driving factor for high PM2.5 mass concentrations during the observation periods. The long-distance transport of sandstorms, characterized by decreasing PM2.5/PM10 ratios (<30%) from the north/northwest, is the most important factor for the explosive growth of PM10 concentration. These results can help us gain a comprehensive understanding of haze formation and highlight the importance of nitrate chemistry in the aqueous phase. The results suggest that persistent NOx emission reduction measures must be made to better achieve air quality standards in Beijing and the NCP region.

2.
Chemosphere ; 242: 125195, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31683164

RESUMO

Fine particulate matter (PM2.5) pollution in Beijing was investigated based on field observation and air quality modeling. Measurement results showed that when using elemental carbon (EC) as the reference component, concurrent increases were observed in the relative abundances of sulfate, nitrate, organic carbon (OC) and water-soluble organic carbon (WSOC) when RH exceeded ∼65% during winter. The observed increases could not be explained by variations of primary biomass burning emissions, instead they likely pointed to heterogeneous chemistry and presumably indicated that formation of secondary inorganic and organic aerosols might be related during winter haze events in Beijing. Large gaps were found in winter when comparing the observational and modeling results. In summer, RH exhibited little influence on the observed sulfate/EC, OC/EC or WSOC/EC, and the observed and modeled results were in general comparable for the concentrations of sulfate, EC and OC. This study suggests that distinct yet poorly-understood atmospheric chemistry may be at play in China's winter haze events, and it could be a substantial challenge to properly incorporate the related mechanisms into air quality models.


Assuntos
Aerossóis/análise , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Estações do Ano , Pequim , Biomassa , Carbono/análise , China , Monitoramento Ambiental/métodos , Material Particulado/análise
3.
Water Sci Technol ; 80(5): 950-960, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31746802

RESUMO

In order to achieve efficient recovery of ions from the simultaneous desulfurization and denitrification wastewater, the effects of various factors (i.e. the saturation temperature, the cooling termination temperature, the stirring rate and the cooling rate) on crystallization yield, metastable zone width and crystal morphology were investigated to determine the optimal crystallization conditions of Mg2+//SO42-, NO3--H2O system. According to the results of experiments, the nucleation kinetics were also speculated by Nývlt self-consistent equation and classical 3D nucleation theory. Also, the crystallization products were characterized by X-ray diffraction and scanning electron microscopy. Under the determined optimal conditions, the yield of the crystal can reach 78%, and the crystal products were verified as pure MgSO4· 7H2O, whose morphology is complete without defects.


Assuntos
Temperatura Baixa , Cristalização , Cinética , Temperatura , Difração de Raios X
4.
Phys Rev Lett ; 123(17): 172301, 2019 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-31702227

RESUMO

We show that the recent proposal to describe the N_{f}=1 baryon in the large number of the color limit as a quantum Hall droplet can be understood as a chiral bag in a (1+2)-dimensional strip using the Cheshire Cat principle. For a small bag radius, the bag reduces to a vortex line which is the smile of the cat with flowing gapless quarks all spinning in the same direction. The disk enclosed by the smile is described by a topological field theory due to the Callan-Harvey anomaly outflow. The chiral bag naturally carries the unit baryon number and spin 1/2N_{c}. The generalization to arbitrary N_{f} is discussed.

5.
Onco Targets Ther ; 12: 5485-5497, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31371987

RESUMO

Background: Chemotherapy is one of the available options for prostate cancer (PC). However, the acquisition of chemoresistance has become a major cause of chemotherapy failure. The long noncoding RNA DANCR is demonstrated to serve as an oncogene in various human cancers, including PC. However, the potential role of DANCR in docetaxel (DTX) resistance of PC and its underlying mechanism remains unclear. Methods: The abundance of DANCR, miR-34a-5p, and JAG1 mRNA was examined by quantitative reverse transcription PCR. The Cell Counting Kit-8 (CCK8) was used to determine the 50% inhibitory concentration value. Cell viability was evaluated by CCK8 and colony-formation assays. Transwells were utilized to analyze cell migration and invasion ability. The protein levels of LRP, P-gp, MRP1, and JAG1 were measured by Western blot assay. The target relationship between DANCR and miR-34a-5p, as well as miR-34a-5p and JAG1, was demonstrated by dual-luciferase, RNA immunoprecipitation, and RNA pull-down analysis. Tumor xenograft was undertaken to confirm the effect of DANCR on DTX resistance in PC. Results: DANCR and JAG1 were significantly upregulated, but miR-34a-5p was downregulated in DTX-resistant PC. Silencing of DANCR improved the DTX efficacy in DTX-resistant PC cells. DANCR served as a competing endogenous RNA of miR-34a-5p, leading to the derepression of miR-34a-5p target JAG1, which eventually triggered the resistance to DTX in DTX-tolerated PC. Conclusion: The DANCR/miR-34a-5p axis enhanced DTX resistance of PC via targeting JAG1, providing a novel insight to improve chemotherapy for PC.

6.
Environ Pollut ; 253: 377-383, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31325882

RESUMO

Changzhou, an industrial city in the Yangtze River Delta, has been experiencing serious haze pollution, particularly in winter. However, studies pertaining to the haze in Changzhou are very limited, which makes it difficult to understand the characteristics and formation of winter haze in this area, and develop effective control measures. In this study, we carried out continuous online observation of particulate matter, chemical components, and meteorology in Changzhou in February 2017. Our results showed that haze pollution occurred frequently in Changzhou winter and exhibited two patterns: dry haze with low relative humidity (RH) and wet haze with high RH. Water-soluble inorganic ions (SO42-, NO3-, and NH4+) accounted for ∼52.2% of the PM2.5 mass, of which sulfate was dominant in wet haze periods while nitrate was dominant in other periods. With the deterioration of haze pollution, the proportion of nitrate in PM2.5 increased, while sulfate proportion increased under wet haze and decreased under dry haze. Dry haze and wet haze appeared under slow north wind and south wind, respectively, and strong north wind or sea breeze scavenged pollution. We found that formation of nitrate occurred rapidly in daytime with high concentrations of odd oxygen (Ox = O3 + NO2), whereas formation of sulfate occurred rapidly during nighttime with high RH, indicating that photochemistry and heterogeneous reaction were the major formation mechanisms for nitrate and sulfate, respectively. Through the cluster analysis of 36-h backward trajectories, five sources of air masses from three directions were identified. High PM2.5 concentrations (84.1 µg m-3 on average) usually occurred under the influence of two clusters (46%) from the northwest, indicating that regional transport from northern China aggravated the winter haze pollution in Changzhou. Emission reduction, particularly the mobile sources, and regional joint prevention and control can help to mitigate the winter haze in Changzhou.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental , Material Particulado/análise , Aerossóis/análise , China , Cidades , Umidade , Meteorologia , Nitratos/análise , Óxidos de Nitrogênio/análise , Rios , Estações do Ano , Sulfatos/análise , Vento
7.
J Environ Sci (China) ; 83: 8-20, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31221390

RESUMO

With rapid economic growth and urbanization, the Yangtze River Delta (YRD) region in China has experienced serious air pollution challenges. In this study, we analyzed the air pollution characteristics and their relationship with emissions and meteorology in the YRD region during 2014-2016. In recent years, the concentrations of all air pollutants, except O3, decreased. Spatially, the PM2.5, PM10, SO2, and CO concentrations were higher in the northern YRD region, and NO2 and O3 were higher in the central YRD region. Based on the number of non-attainment days (i.e., days with air quality index greater than 100), PM2.5 was the largest contributor to air pollution in the YRD region, followed by O3, PM10, and NO2. However, particulate matter pollution has declined gradually, while O3 pollution worsened. Meteorological conditions mainly influenced day-to-day variations in pollutant concentrations. PM2.5 concentration was inversely related to wind speed, while O3 concentration was positively correlated with temperature and negatively correlated with relative humidity. The air quality improvement in recent years was mainly attributed to emission reductions. During 2014-2016, PM2.5, PM10, SO2, NOx, CO, NH3, and volatile organic compound (VOC) emissions in the YRD region were reduced by 26.3%, 29.2%, 32.4%, 8.1%, 15.9%, 4.5%, and 0.3%, respectively. Regional transport also contributed to the air pollution. During regional haze periods, pollutants from North China and East China aggravated the pollution in the YRD region. Our findings suggest that emission reduction and regional joint prevention and control helped to improve the air quality in the YRD region.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/estatística & dados numéricos , Monitoramento Ambiental , Conceitos Meteorológicos , China , Meteorologia , Ozônio , Material Particulado/análise , Rios , Estações do Ano , Temperatura , Urbanização
8.
Pathol Oncol Res ; 2019 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-31190217

RESUMO

To assess the associations between O6-methylguanine-DNA methyltransferase(MGMT) polymorphisms and prostate cancer risk. We retrieved PubMed, Cochrane Library and Embase electronic database to search for all eligible studies published from Jan 1, 1970 to Sep 31, 2017 to conduct a Meta-analysis. we identified 11 independent studies in 5 eligible reports, including 5143 cases and 8118 controls. The data suggested that rs12917 was associated with higher PCa risk under the contrast of TT vs CC and recessive model in overall population (TT vs CC: OR = 1.599, 95%CI: 1.007-2.539, P = 0.047; TT vs CC + CT: OR = 1.627, 95%CI: 1.026-2.580, P = 0.038). In subgroup analyses stratified by ethnicity, the remarkable association with higher PCa risk was detected under allelic model, dominant model, the contrast of TC vs CC, and the contrast of TC vs CC + TT in Asian population. (T vs C: OR = 1.911, 95%CI: 1.182-3.090, P = 0.008; TC vs CC: OR = 1.948, 95%CI: 1.152-3.295, P = 0.013; TC + TT vs CC: OR = 1.994, 95%CI: 1.190-3.342, P = 0.009; TC vs CC + TT: OR = 1.926, 95%CI: 1.140-3.255, P = 0.014). However, the data suggest the rs2308327 and rs2308321 polymorphisms of the MGMT gene were nor associated with the susceptibility of prostate cancer. Based on the meta-analysis, MGMT rs12917 polymorphism increase the susceptibility to prostate cancer, which can be taken for a diagnosis and screening molecular biomarker for prostate cancer patients.

9.
Cell Biol Int ; 2019 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-31228307

RESUMO

Prostate cancer (PCa) is a common cancer worldwide, which mostly occurs in males over the age of 50. Accumulating evidence have determined that long non-coding RNA/microRNA (lncRNA/miRNA) axis plays a critical role in cell progression of cancers, including PCa. However, the pathogenesis of PCa has not been fully indicated. In this study, quantitative real-time polymerase chain reaction was used to detect the expression of HCG11 and miR-543. Western blot was applied to measure the protein expression of proliferating cell nuclear antigen, cleavage-caspase 3 (cle-caspase 3), N-cadherin, E-cadherin, GAPDH, P-AKT, AKT, p-mTOR, and mTOR. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), transwell invasion, and transwell migration assay were used to detect cell proliferation, invasion, and migration, respectively. The function and mechanism of lncRNA HCG11 were confirmed in PCa cell and xenograft mice models. Luciferase assay indicated that miR-543 was a target miRNA of HCG11. Further investigation revealed that overexpression of HCG11 inhibited cell proliferation, invasion, and migration, whereas induced cell apoptosis by regulating miR-543 expression in vitro and in vivo. More than that, lncRNA HCG11 inhibited phosphoinositide-3 kinase/protein kinaseB (PI3K/AKT) signaling pathway to suppress PCa progression. Our data showed the overexpression of HGC11-inhibited PI3K/AKT signaling pathway by downregulating miR-543 expression, resulting in the suppression of cell growth in PCa. This finding proved a new regulatory network in PCa and provided a novel therapeutic target of PCa.

10.
Environ Pollut ; 250: 914-921, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31085478

RESUMO

China has been faced with severe haze pollution, which is hazardous to human health. Among the air pollutants, PM2.5 (particles with an aerodynamic diameter ≤ 2.5 µm) is the most dangerous because of its toxicity and impact on human health and ecosystems. However, there has been limited research on PM2.5 particle toxicity. In the present study, we collected daily PM2.5 samples from January 1 to March 31, 2018 and selected samples to extract water-soluble species, including SO42-, NO3-, WSOC, and NH4+. These samples represented clean, good, slight, moderate, and heavy pollution days. After extraction using an ultrasonic method, PM2.5 solutions were obtained. We used Chlorella as the test algae and studied the content of chlorophyll a, as well as the variation in fluorescence when they were placed into the PM2.5 extraction solution, and their submicroscopic structure was analyzed using transmission electron microscopy (TEM). The results showed that when the air quality was relatively clean and good (PM2.5 concentration ≤ 75 µg m-3), the PM2.5 extraction solutions had no inhibiting effects on Chlorella, whereas when the air quality was polluted (PM2.5 concentration > 75 µg m-3) and heavily polluted (PM2.5 concentration > 150 µg m-3), with increasing PM2.5 concentrations and exposure time, the chlorophyll a content in Chlorella decreased. Moreover, the maximum photochemical quantum yield (Fv/Fm) of Chlorella obviously decreased, indicating chlorophyll inhibition during polluted days with increasing PM2.5 concentrations. The effects on the chlorophyll fluorescence parameters were also obvious, leading to an increase of energy dissipated per unit reaction center (DIo/RC), suggesting that Chlorella could survive when exposed to PM2.5 solutions, whereas the physiological activities were significantly inhibited. The TEM analysis showed that there were few effects on Chlorella cell microstructure during clean days, whereas plasmolysis occurred during light- and medium-polluted days. With increasing pollution levels, plasmolysis became more and more apparent, until the organelles inside the cells were thoroughly destroyed and most of the parts could not be recognized.


Assuntos
Poluentes Atmosféricos/toxicidade , Poluição do Ar/análise , Chlorella/efeitos dos fármacos , Monitoramento Ambiental/métodos , Material Particulado/toxicidade , Poluentes Atmosféricos/análise , China , Chlorella/metabolismo , Clorofila A/metabolismo , Humanos , Tamanho da Partícula , Material Particulado/análise , Solubilidade , Testes de Toxicidade , Água/química
11.
Environ Pollut ; 244: 84-92, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30326389

RESUMO

Organic aerosol (OA) are always the most abundant species in terms of relative proportion to PM2.5 concentration in Beijing, while in previous studies, poor link between carbonaceous particles and their gaseous precursors were established based on field observation results. Through this study, we provided a comprehensive analysis of critical carbonaceous species in the atmosphere. The concentrations, diurnal variations, conversions, and gas-particle partitioning (F-factor) of 8 carbonaceous species, carbon dioxide (CO2), carbon monoxide (CO), methane (CH4), volatile organic compounds (VOCs), non-methane hydrocarbon (NMHC), organic carbon (OC), elemental carbon (EC), and water soluble organic compounds (WSOCs), in Beijing were analyzed synthetically. Carbonaceous gases (CO, CO2, VOCs, and CH4) and OC/EC ratios exhibited double-peak diurnal patterns with a pronounced midnight peak, especially in winter. High correlation between VOCs and OC during winter nighttime indicated that OC was formed from VOCs precursors via an unknown mechanism at relative humidity greater than 50% and 80%, thereby promoting WSOC formation in PM1 and PM2.5 respectively. The established F-factor method was effective to describe gas-to-particle transformation of carbonaceous species and was a good indicator for haze events since high F-factors corresponded with enhanced PM2.5 level. Moreover, higher F-factors in winter indicated carbonaceous species were more likely to exist as particles in Beijing. These results can help gain a comprehensive understanding of carbon cycle and formation of secondary organic aerosols from gaseous precursors in the atmosphere.


Assuntos
Poluentes Atmosféricos/análise , Carbono/análise , Monitoramento Ambiental/métodos , Umidade , Compostos Orgânicos/análise , Material Particulado/análise , Estações do Ano , Aerossóis/análise , Poluição do Ar , Atmosfera/análise , Pequim , Ciclo do Carbono , Dióxido de Carbono/análise , Monóxido de Carbono/análise , China , Metano/análise , Tamanho da Partícula , Compostos Orgânicos Voláteis/análise , Água/análise
12.
Sci Total Environ ; 656: 239-249, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30504024

RESUMO

Black carbon (BC) is important due to its complex influences on the environment and on climate in particular. However, reported BC data are largely dependent on measurement techniques due to the multitude of measurement principles. Here we focused on thermal-optical method which has been widely used to determine BC mass (as elemental carbon, EC). Several factors influencing EC measurement were investigated. Results from source samples representing vehicle engine emissions pointed to a continuum of EC components in thermal stability and provided direct observational evidence for the premature evolution of EC in inert atmosphere. It was also found that EC masses may be substantially underestimated for the vehicle exhaust samples if the adopted protocol requires an oxidizing atmosphere to define the split point between organic carbon (OC) and EC. Results from a field campaign conducted during winter in Beijing showed that the optical attenuation (ATN; i.e., the filter transmittance signal, I) was largely saturated for the samples with relatively high loadings, indicating their EC results were unreliable. Improved measurement of EC was achieved by extracting these heavily loaded filters using methanol, given that ATN was considerably reduced by the extraction and, moreover, saturation of ATN (or I) became not evident for the extracted samples. The methanol extraction also significantly reduced the transformation of OC to char-OC, by removing the majority (i.e., ~85%) of the deposited organic aerosols. Higher EC were measured for the extracted samples compared with the untreated ones, indicating that EC tends to be underestimated due to the charring-induced uncertainties. In addition, the methanol extraction largely reduced the inter-protocol discrepancy in the EC measurement results. Similar effects of methanol extraction have been observed during summer in Beijing, despite the seasonal variations of aerosol sources and compositions. This study indicates the potential benefits of methanol extraction for EC measurement.

13.
Chemosphere ; 212: 1010-1019, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30286530

RESUMO

Carbonaceous aerosol was measured during fall of 2010 in Beijing. Daily variation of organic carbon (OC) was found to coincide with that of relative humidity (RH), and the OC to elemental carbon (EC) ratios were more than doubled during the more humid periods (RH above 0.75) compared to other conditions. This large increase in OC/EC could not be explained by the variations of primary biomass burning emissions but was accompanied by a five-fold increase in the sulfate to EC ratio. It was then inferred that secondary organic aerosol (SOA) formation was enhanced under the more humid conditions, presumably through aqueous-phase processes. This enhanced SOA formation might be partially associated with particles externally mixed with black carbon, as indicated by the RH-dependent relationships between aerosol optical attenuation and EC loading. In addition, organic aerosols exhibited different properties between the more humid and the other periods, such that they were less volatile and charred more significantly during thermal-optical analysis in the former case. These differences coincided with the evidence of enhanced SOA formation under the more humid conditions. This study highlights the necessity of incorporating aqueous-phase chemistry into air quality models for SOA.


Assuntos
Aerossóis/análise , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Monitoramento Ambiental/métodos , Pequim , Carbono/química , Material Particulado/análise , Estações do Ano , Água/química
14.
Environ Pollut ; 242(Pt A): 544-554, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30007265

RESUMO

Continuous haze monitoring was conducted from 12:00 3 April to 12:00 8 April 2016 in Beijing, China to develop a more detailed understanding of spring haze characteristics. The PM2.5 concentration ranged from 6.30 to 165 µg m-3 with an average of 63.8 µg m-3. Nitrate was the most abundant species, accounting for 36.4% of PM2.5, followed by organic carbon (21.5%), NH4+ (19.3%), SO42- (18.8%), and elemental carbon (4.10%), indicating the key role of nitrate in this haze event. Species contribution varied based on the phase of the haze event. For example, sulfate concentration was high during the haze formation phase, nitrate was high during the haze, and secondary organic carbon (SOC) had the highest contribution during the scavenging phase. The secondary transition of sulfate was influenced by SO2, followed by relative humidity (RH) and Ox (O3+NO2). Nitrate formation occurred in two stages: through NO2 oxidation, which was vulnerable to Ox; and by the partitioning of N (+5) which was susceptible to RH and temperature. SOC tended to form when Ox and RH were balanced. According to hourly species behavior, sulfate and nitrate were enriched during haze formation when the mixed layer height decreased. However, SOC accumulated prior to the haze event and during formation, which demonstrated the strong contribution of secondary inorganic aerosols, and the limiting contribution of SOC to this haze case. Investigating backward trajectories showed that high speed northwestern air masses following a straight path corresponded to the clear periods, while southwesterly air masses which traversed heavily polluted regions brought abundant pollutants to Beijing and stimulated the occurrence of haze pollution. Results indicate that the control of NO2 needs to be addressed to reduce spring haze. Finally, the correlation between air mass trajectories and pollution conditions in Beijing reinforce the necessity of inter-regional cooperation and control.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental , Material Particulado/análise , Aerossóis/análise , Poluição do Ar/análise , Poluição do Ar/estatística & dados numéricos , Pequim , Carbono , China , Nitratos/análise , Estações do Ano , Sulfatos/análise , Transportes
15.
J Hazard Mater ; 342: 579-588, 2018 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-28892795

RESUMO

The forced oxidation of magnesium sulfite (MgSO3) aims to not only reclaim the by-product in the magnesia desulfurization, but also lower the risk of secondary pollution. The non-porous titanium dioxide nanoparticle was used as a support to prepare the cobalt catalyst (Co-TiO2) in order to expedite the oxidation rate. This fabricated Co-TiO2 was characterized by inductively coupled plasma optical emission spectroscopy (ICP-OES), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), and energy dispersive spectroscopy (EDS) to figure out its catalytic mechanism. The results revealed that the cobalt nanoparticles were uniformly dispersed on the surface of the TiO2 in forms of Co3O4 and Co2O3. The kinetics of the MgSO3 oxidation catalyzed by the prepared Co-TiO2 was investigated in a bubbling tank reactor, indicating that the oxidation rate was dependent on the catalyst concentration, oxygen partial pressure, pH value, and the reaction temperature. Compared with the reported porous catalyst (Co-CNTs), the activation energy with the Co-TiO2 (17.29kJmol-1) decreased by 50.9%, resulting in a good catalytic performance in sulfite oxidation. The findings will help advance the industrial application of the novel magnesia desulfurization process.

16.
Cell Physiol Biochem ; 43(3): 1003-1011, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28968601

RESUMO

BACKGROUND/AIMS: Tetrandrine and Fangchinoline (Fcn) are two natural products that are found in Stephania tetrandra. Tetrandrine is a known anti-bladder cancer compound, but the effects of Fcn on bladder cancer have been previously unclear. In the present study, we focused on the anti-tumor effects of Fcn on bladder cancer. METHODS AND RESULTS: We treated T24 and 5637 bladder cancer cell lines with Fcn in vitro. We observed that Fcn inhibited the viability of bladder cancer cells in a concentration-dependent manner. The expression of PCNA, a biomarker of proliferation, was down-regulated. Fcn treatment induced both apoptosis and autophagy in bladder cancer cells, as shown by the increased cleavage of caspase-3, an up-regulated LC3-II/LC3-I ratio and the down-regulated p62 level. Blocking autophagy with 3-MA (3-Methyladenine) enhanced Fcn-induced apoptosis, indicating that Fcn-induced autophagy was adaptive. Additionally, we observed that Fcn treatment inhibited mTOR and reduced the intracellular ATP levels. The exogenous addition of methyl pyruvate (MP) to compensate metabolic substrates alleviated Fcn-induced apoptosis and autophagy. CONCLUSIONS: Our data indicated that Fcn caused an impairment in energy generation, which led to apoptosis and adaptive autophagy in bladder cancer. These results demonstrated that Fcn may be a potential candidate for use in the prevention and treatment of bladder cancer.


Assuntos
Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Benzilisoquinolinas/farmacologia , Adenina/análogos & derivados , Adenina/farmacologia , Trifosfato de Adenosina/metabolismo , Antineoplásicos/farmacologia , Caspase 3/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Proteínas Associadas aos Microtúbulos/metabolismo , Antígeno Nuclear de Célula em Proliferação/metabolismo , Piruvatos/farmacologia , Proteínas de Ligação a RNA/metabolismo , Stephania tetrandra/química , Stephania tetrandra/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Neoplasias da Bexiga Urinária/metabolismo , Neoplasias da Bexiga Urinária/patologia
17.
Environ Pollut ; 229: 339-349, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28609735

RESUMO

Heavy haze pollution occurs frequently in northern China, most critically in the Beijing-Tianjin-Hebei area (BTH). Zibo, an industrial city located in Shandong province, is often listed as one of the top ten most polluted cities in China, particularly in winter. However, no studies of haze in Zibo have been conducted, which limits the understanding of the source and formation of haze pollution in this area, as well as mutual effects with the BTH area. We carried out online and continuous integrated field observation of particulate matter in winter, from 11 to 25 January 2015. SO42-, NO3-, and NH4+ (SIA) and organics were the main constituents of PM2.5, contributing 59.4% and 33.6%, respectively. With the increasing severity of pollution, the contribution of SIA increased while that of organics decreased. Meteorological conditions play an important role in haze formation; high relative humidity (RH) and low wind speed increased both the accumulation of pollutants and the secondary transition from gas precursors (gas-particle phase partitioning). Since RH and the presence of O3 can indicate heterogeneous and photochemistry processes, respectively, we carried out correlation analysis and linear regression to identify their relative importance to the three main secondary species (sulfate, nitrate, and secondary organic carbon (SOC)). We found that the impact of RH is in the order of SO42- > NO3- > SOC, while the impact of O3 is reversed, in the order of SOC > NO3- > SO42-, indicating different effect of these factors on the secondary formation of main species in winter. Cluster analysis of backward trajectories showed that, during the observation period, six directional sources of air masses were identified, and more than 90% came from highly industrialized areas, indicating that regional transport from industrialized areas aggravates the haze pollution in Zibo. Inter-regional joint prevention and control is necessary to prevent further deterioration of the air quality.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/estatística & dados numéricos , Monitoramento Ambiental , Material Particulado/análise , Aerossóis/análise , Poluição do Ar/análise , Pequim , China , Cidades , Poluição Ambiental , Umidade , Meteorologia , Nitratos/análise , Estações do Ano , Sulfatos/análise , Vento
18.
Environ Pollut ; 227: 296-305, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28477554

RESUMO

Four haze episodes (EPs) were observed in October 2014 in Beijing, China. For better understanding of the characteristics and the formation mechanisms of PM2.5 (particulate matter with an aerodynamic diameter ≤ 2.5 µm), especially secondary water-soluble inorganic species in these haze events, hourly concentrations of PM2.5, sulfate, nitrate, and ammonium (SNA) were measured in this study. Concentrations of gaseous pollutants and meteorological parameters were also measured. The average concentration of PM2.5 was 106.6 ± 83.5 µg m-3, which accounted for around 53% of PM10 (particulate matter with an aerodynamic diameter ≤ 10 µm) mass. Nitrogen dioxide (NO2) concentration was much higher than that of sulfur dioxide (SO2) since October is a non-heating month. SNA is the most abundant secondary water-soluble inorganic species and contributed to 33% of PM2.5 mass concentration. Sulfur oxidation ratio (SOR) was much higher than nitrogen oxidation ratio (NOR). NOR and SOR increased with elevated PM2.5 levels and heterogeneous processes seemed to be the most plausible explanation of this increase. Relative humidity (RH), which is of great influence on aerosol liquid water content (ALWC), played a considerable role in the formation of secondary inorganic aerosols, accelerated the secondary transformation of gaseous precursors, and further aggravated haze pollution. The positive feedback loop associated with high aerosol levels and low planetary boundary layer (PBL) height led to the evolution and exacerbation of heavy haze pollution. Fire maps and 48-h air mass backward trajectories supported the significant impact of biomass burning activities and regional transport on haze formation over Beijing in October 2014.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental , Material Particulado/análise , Aerossóis/análise , Pequim , China , Meteorologia , Nitratos/análise , Dióxido de Nitrogênio , Estações do Ano , Solubilidade , Sulfatos/análise , Dióxido de Enxofre , Água
19.
Huan Jing Ke Xue ; 38(10): 4054-4060, 2017 Oct 08.
Artigo em Chinês | MEDLINE | ID: mdl-29965187

RESUMO

In order to investigate the chemical characteristics and sources of atmospheric heavy metals, PM2.5 samples were collected every three days during the summer of 2011 and summer of 2012. The samples were analyzed for Li, V, Cr, Mn, Co, Cu, Zn, As, Se, Ti, Ga, Ni, Sr, Cd, In, Ba, Tl, Pb, Bi, and U by ICP-MS, with an emphasis on seven major heavy metal elements (Zn, Pb, Mn, Cu, As, V, and Cr). The concentrations of Zn, Pb, Mn, Cu, As, V, and Cr were (331.30±254.52), (212.64±182.06), (85.96±47.00), (45.19±27.74), (17.13±19.02), (4.92±3.38), and (9.04±7.84) ng·m-3 in PM2.5 in Beijing during the summer of 2011 and the summer of 2012. In the autumn and winter seasons, PM2.5/heavy metal pollution is more severe than in spring and summer, which may be related to the increase in coal combustion used for heating in autumn and winter in Beijing. Haze pollution enhances the concentrations of seven heavy metals in PM2.5 in Beijing and the enhancement shows seasonal variations. The source analysis suggested that dust (including building dust and road dust) and coal combustion might be two most important sources of heavy metals in Beijing, and transport and other industrial sources cannot be ignored.

20.
Sci Rep ; 6: 34891, 2016 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-27731344

RESUMO

Although air quality monitoring networks have been greatly improved, interpreting their expanding data in both simple and efficient ways remains challenging. Therefore, needed are new analytical methods. We developed such a method based on the comparison of pollutant concentrations between target and circum areas (circum comparison for short), and tested its applications by assessing the air pollution in Jing-Jin-Ji, Yangtze River Delta, Pearl River Delta and Cheng-Yu, China during 2015. We found the circum comparison can instantly judge whether a city is a pollution permeation donor or a pollution permeation receptor by a Pollution Permeation Index (PPI). Furthermore, a PPI-related estimated concentration (original concentration plus halved average concentration difference) can be used to identify some overestimations and underestimations. Besides, it can help explain pollution process (e.g., Beijing's PM2.5 maybe largely promoted by non-local SO2) though not aiming at it. Moreover, it is applicable to any region, easy-to-handle, and able to boost more new analytical methods. These advantages, despite its disadvantages in considering the whole process jointly influenced by complex physical and chemical factors, demonstrate that the PPI based circum comparison can be efficiently used in assessing air pollution by yielding instructive results, without the absolute need for complex operations.

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