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1.
Phys Rev Lett ; 125(14): 142501, 2020 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-33064499

RESUMO

The recent RIKEN experiment on the quenched g_{A} in the superallowed Gamow-Teller transition from ^{100}Sn indicates the role of scale anomaly encoded in the anomalous dimension ß^{'} of the gluonic stress tensor Tr G_{µν}^{2}. This observation provides support to the notion of hidden scale symmetry emerging by strong nuclear correlations with an infrared (IR) fixed point realized-in the chiral limit-in the Nambu-Goldstone mode. We suggest there is an analogy in the way scale symmetry manifests in a nuclear medium to the continuity from the unitarity limit at low density (in light nuclei) to the dilaton limit at high density (in compact stars). In between the limits, say, at normal nuclear matter density, the symmetry is not visible, hence hidden.

2.
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.

3.
Cell Biol Int ; 43(12): 1453-1462, 2019 Dec.
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.

4.
Environ Sci Technol ; 45(23): 10117-23, 2011 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-22044188

RESUMO

An intercomparison of organic carbon (OC) and elemental carbon (EC) measurements was conducted based on ambient aerosol samples collected during four seasons in Beijing, China. Dependence of OC and EC values on the temperature protocol and the charring correction method is presented and influences of aerosol composition are investigated. EC was found to decrease with the peak inert mode temperature (T(peak)) such that EC determined by the IMPROVE (the Interagency Monitoring of Protected Visual Environments)-A protocol (T(peak) was 580 °C) was 2.85 ± 1.31 and 3.83 ± 2.58 times that measured by an alternative protocol with a T(peak) of 850 °C when using the transmittance and reflectance correction, respectively. It was also found that reflectance correction tends to classify more carbon as EC compared with transmittance; results from the IMPROVE-A protocol showed that the ratio of EC defined by reflectance correction (EC(R)) to that based on transmittance (EC(T)) averaged 1.50 ± 0.42. Moreover, it was demonstrated that emissions from biomass burning would increase the discrepancy between EC values determined by different temperature protocols. On the other hand, the discrepancy between EC(R) and EC(T) was strongly associated with secondary organic aerosol (SOA) which was shown to be an important source of the organics that pyrolyze during the inert mode of thermal-optical analysis.


Assuntos
Aerossóis/análise , Carbono/análise , Compostos Orgânicos/análise , China , Monitoramento Ambiental
5.
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
6.
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.

7.
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
8.
Huan Jing Ke Xue ; 38(10): 4054-4060, 2017 Oct 08.
Artigo em Zh | 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.

9.
World J Gastroenterol ; 12(41): 6715-21, 2006 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-17075991

RESUMO

AIM: To observe the efficiency and safety of thymosin-alpha1 treatment in patients with hepatitis B e antigen (HBeAg) and HBV DNA positive chronic hepatitis. METHODS: Sixty-two patients were randomly divided into groups A and B. The patients in group A received subcutaneous injection of 1.6 mg thymosin-alpha1, twice a week (T-alpha1 group) for six months, and the patients in group B received 5 MU interferon alpha (IFN-alpha) each day for fifteen days, then three times weekly (IFN-alpha group) for six months. The results between two groups treated with and the group untreated with IFN-alpha which was followed up for 12 mo (historical control group consisting of 30 patients) were compared, and three groups were comparable between each other (P>0.05) at baseline (age, sex, clinical history, biochemical, and serological parameters). RESULTS: At the end of treatment, complete response, which was defined as alanine aminotransferase (ALT) normalization and HBV DNA and HBeAg loss, occurred in 9 of 29 (31.0%) patients in the T-alpha1 group and in 15 of 33 (45.5%) patients in the IFN-alpha group (chi2=1.36, P>0.05). After a follow-up period of six months, a complete response was observed in 14 of 29 (48.3%) patients in the T-alpha1 group and in 9 of 33 (27.3%) patients in the IFN-alpha group (chi2=2.93, P>0.05). Compared with the results observed in the historical control (HC) group untreated with IFN-alpha which was followed up for 12 mo, the rate of complete response was significantly higher in IFN-alpha group at the end of therapy (1 of 30 vs 15 of 33, chi2=14.72, P<0.001) and in the T-alpha1 group at the end of follow-up (1 of 30 vs 14 of 29, chi2=15.71, P<0.001). In T-alpha1 and IFN-alpha treatment groups, the area under (the plasma concentration time) curve (AUC) of negative HBV DNA and HBeAg was 34%, 17%, 31% and 19% smaller than that in the HC group. By the end of the follow-up period, the proportions of ALT normalization and negative HBV DNA in the T-alpha1 group were significantly higher than those in the IFN-alpha and HC groups. The odds of ALT normalization and negative HBV DNA at the end of the follow-up was three-fold higher in the T-alpha1 group than in the IFN-alpha group. Unlike IFN-alpha, T-alpha1 was well tolerated by all patients, and no side effects appeared in T-alpha1 group. CONCLUSION: The results suggest that a 6-mo course of T-alpha1 therapy is effective and safe in patients with chronic hepatitis B. T-alpha1 is able to reduce HBV replication in patients with chronic hepatitis B. Furthermore, T-alpha1 is better tolerated than IFN-alpha and can gradually induce more sustained ALT normalization and HBV DNA and HBeAg loss. However, a response rate of 48.3% is still less ideal. A more effective therapeutic approach warrants further study.


Assuntos
Adjuvantes Imunológicos/uso terapêutico , Antivirais/uso terapêutico , Hepatite B Crônica/tratamento farmacológico , Interferon-alfa/uso terapêutico , Timosina/análogos & derivados , Adjuvantes Imunológicos/efeitos adversos , Adjuvantes Imunológicos/farmacologia , Adulto , Alanina Transaminase/sangue , Antivirais/efeitos adversos , Antivirais/farmacologia , DNA Viral/sangue , Relação Dose-Resposta a Droga , Feminino , Antígenos E da Hepatite B/sangue , Vírus da Hepatite B/genética , Hepatite B Crônica/sangue , Hepatite B Crônica/imunologia , Humanos , Interferon-alfa/efeitos adversos , Interferon-alfa/farmacologia , Masculino , Pessoa de Meia-Idade , Timalfasina , Timosina/efeitos adversos , Timosina/farmacologia , Timosina/uso terapêutico , Replicação Viral/efeitos dos fármacos
10.
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.

11.
Environ Int ; 86: 150-70, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26595670

RESUMO

Recently, PM2.5 (atmospheric fine particulate matter with aerodynamic diameter ≤ 2.5 µm) have received so much attention that the observations, source appointment and countermeasures of it have been widely studied due to its harmful impacts on visibility, mood (mental health), physical health, traffic safety, construction, economy and nature, as well as its complex interaction with climate. A review on the PM2.5 related research is necessary. We start with summary of chemical composition and characteristics of PM2.5 that contains both macro and micro observation results and analysis, wherein the temporal variability of concentrations of PM2.5 and major components in many recent reports is embraced. This is closely followed by an overview of source appointment, including the composition and sources of PM2.5 in different countries in the six inhabitable continents based on the best available results. Besides summarizing PM2.5 pollution countermeasures by policy, planning, technology and ideology, the World Air Day is proposed to be established to inspire and promote the crucial social action in energy-saving and emission-reduction. Some updated knowledge of the important topics (such as formation and evolution mechanisms of hazes, secondary aerosols, aerosol mass spectrometer, organic tracers, radiocarbon, emissions, solutions for air pollution problems, etc.) is also included in the present review by logically synthesizing the studies. In addition, the key research challenges and future directions are put forward. Despite our efforts, our understanding of the recent reported observations, source identifications and countermeasures of PM2.5 is limited, and subsequent efforts both of the authors and readers are needed.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar , Monitoramento Ambiental/métodos , Material Particulado/análise , Aerossóis/análise , Microbiologia do Ar/normas , Poluentes Atmosféricos/química , Poluição do Ar/análise , Poluição do Ar/prevenção & controle , Clima , Humanos , Tamanho da Partícula , Material Particulado/química
12.
Huan Jing Ke Xue ; 37(3): 801-6, 2016 Mar 15.
Artigo em Zh | MEDLINE | ID: mdl-27337869

RESUMO

Pollution characteristic and variation trend of atmospheric carbonyls were investigated in November during the 2014 Beijing APEC. Formaldehyde, acetaldehyde and acetone were the dominant carbonyls, accounting for 82.66% of total carbonyls, and especially, formaldehyde accounted for 40.12% of total carbonyls. Atmospheric concentrations of total carbonyls decreased by around 64.10% after the clean air policy was carried out during the Beijing APEC, and the variation trend of carbonyls showed a similar pattern to those of other pollutants like PM2.5 during the APEC. Strong correlations (R² of 0.67-0.98) were observed among formaldehyde, acetaldehyde, acetone and total carbonyls during and after the APEC, indicating that they had similar sources; however, poor correlations (R² of -0.11-0.42 and 0.16-0.94, respectively) were observed before the APEC, implying different emission sources for ambient carbonyls. The calculated ratios of C1/C2, C2/C3 and OC/EC indicated that both vehicles and coal emissions were responsible for atmospheric carbonyls before the APEC, and emissions from coal burning were the major contributor to atmospheric carbonyls during and after the APEC, especially after the APEC.


Assuntos
Acetaldeído/análise , Acetona/análise , Poluentes Atmosféricos/análise , Monitoramento Ambiental , Formaldeído/análise , Pequim , Carvão Mineral , Tamanho da Partícula , Material Particulado/análise
13.
Huan Jing Ke Xue ; 37(5): 1602-8, 2016 May 15.
Artigo em Zh | MEDLINE | ID: mdl-27506010

RESUMO

In order to investigate the influence of the emission reduction measure during the Beijing APEC on the concentrations and pollution characteristics of humic-like substances (HULIS) in atmospheric fine particles, PM2.5 samples were collected and analyzed for OCEC, WSOC, HULIS and water-soluble ions. The concentration of HULIS in PM2.5 ranged 1 µg · m⁻³-15 µg · m⁻³. HULIS concentrations were 7.99 µg · m⁻³, 5.83 µg · m⁻³ and 7.06 µg · m⁻³ before, during and after APEC, which indicated emission reduction measure had important effect on the reduction of HULlS. The decrease of HULIS during the APEC was significantly faster than those of EC and WSOC, while the increase of HULIS turned out to be much slower than OC, EC, WSOC and PM2.5 after the meeting. The proportions of HULIS to PM2.5 were 13.60%, 13.59%, 14.02% and 12.22% at four different stages, i. e., whole sampling period, before, during and after the APEC, while HULIS-C/OC and HULIS-C/WSOC were 28.95%, 35.51%, 28.37%, 19.93%; and 52.75%, 59.58%, 51.54%, 45.39%, respectively. HULlS was significantly positively correlated with humidity, while significantly negatively correlated with wind speed. Biomass burning and secondary transformation of VOCs might be two important sources of HULlS in Beijing.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental , Substâncias Húmicas/análise , Material Particulado/análise , Pequim , Tamanho da Partícula
14.
Huan Jing Ke Xue ; 37(7): 2428-2435, 2016 Jul 08.
Artigo em Zh | MEDLINE | ID: mdl-29964447

RESUMO

Polycyclic aromatic hydrocarbons (PAHs) are a group of important toxic compounds. In order to detect the pollutional characteristics of atmospheric PAHs in Fine Particulate Matter (PM2.5), a total of 60 PM2.5 samples were collected in Lanzhou City during the winter of 2012 and summer of 2013. The GC/MS measurement results of the samples demonstrated the averagely total mass concentrations of the most significant 16 homologues of PAHs were (191.79±88.29) ng·m-3 and (8.94±4.34) ng·m-3 in winter and summer respectively, indicating a higher pollution level in winter. In winter, the snowfall was the most important meteorological factor for the decrease of PAHs mass concentration in PM2.5. The percentages of PAHs with 4 rings were the highest in both winter (51.40%) and summer (49.94%) in Lanzhou. The percentage of PAHs with 5-6 rings in summer (41.04%) was higher than that in winter (24.94%). However, the percentage of PAHs with 2-3 rings in summer (9.03%) was lower than that in winter (23.67%). Based on the analysis of characteristic ratios, we concluded that the PAHs in atmospheric PM2.5 in Lanzhou were mainly sourced from coal and vehicle emissions in winter, especially the diesel vehicles. The absolute contributions of all possible PAHs pollution sources were insignificant in summer, with relatively higher contribution from gasoline vehicles.

15.
Huan Jing Ke Xue ; 37(11): 4124-4132, 2016 Nov 08.
Artigo em Zh | MEDLINE | ID: mdl-29964661

RESUMO

Thirty non-methane hydrocarbons(NMHCs) samples were collected and analyzed in Foshan City during winter 2014 and summer 2015. The concentrations of NMHCs during the sampling period were 122.30 µg·m-3 and 56.22 µg·m-3 in winter and summer, respectively. The five highest concentration species of NMHCs in winter and summer were in the following order: toluene (25.12 µg·m-3), m/p-xylene (13.76 µg·m-3), propane (9.17 µg·m-3), ethylbenzene (7.25 µg·m-3), ethylene (6.77 µg·m-3) and toluene (6.18 µg·m-3), m/p-xylene (5.21 µg·m-3), o-xylene (4.15 µg·m-3), ß-pinene(3.75 µg·m-3), propane (3.29 µg·m-3). Compared to 2008, the concentrations of NMHCs have dropped significantly. The proportions of aromatics, alkanes, alkenes and alkynes in NMHCs were 51.20%, 34.70%, 10.04%, 4.05% and 43.93%, 33.99%, 19.20%, 2.88% during winter and summer, respectively. The ratios of NMHCs/NOx were 0.90 and 1.88, indicating that the peak ozone concentrations in Foshan City were controlled by NMHCs during the sampling period, and the emissions of NMHCs should be further strengthened. The propylene equivalent concentration and ozone formation potential were 45.09 µg·m-3 and 40.64 µg·m-3, 392.77 µg·m-3 and 207.77 µg·m-3 in winter and summer. The m/p-xylene; toluene and m/p-xylene; isoprene had a very important influence on ozone formation potential. The ratios of Benzene/Toluene were 0.15 and 0.20 indicated that industrial process was the main source of NMHCs in Foshan City. Relative to 2008, isopentane didn't belong to the highest concentration of five pollutants for Foshan's NMHCs in this research, indicating the measures to prevent volatile gasoline impact on the environmental quality have achieved remarkable results.

16.
Chemosphere ; 155: 70-85, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27108365

RESUMO

In this study we investigated the distribution patterns, infiltration and health risk assessment of PM2.5-bound PAHs in indoor and outdoor air done in Harbin city, northeastern China. Simultaneous indoor and outdoor sampling was done to collect 264 PM2.5 samples from four sites during winter, summer, and spring. Infiltration of PAHs into indoors was estimated using Retene, Benzo [ghi]perylene and Chrysene as reference compounds, where the latter compound was suggested to be a good estimator and subsequently used for further calculation of infiltration factors (IFs). Modeling with positive matrix factorization (PMF5) and estimation of diagnostic isomeric ratios were applied for identifying sources, where coal combustion, crop residues burning and traffic being the major contributors, particularly during winter. Linear discriminant analysis (LDA) has been utilized to show the distribution patterns of individual PAH congeners. LDA showed that, the greatest seasonal variability was attributed to high molecular weight compounds (HMW PAHs). Potential health risk of PAHs exposure was assessed through relative potency factor approach (RPF). The levels of the sum of 16 US EPA priority PAHs during colder months were very high, with average values of 377 ± 228 ng m(-)(3) and 102 ± 75.8 ng m(-)(3), for the outdoors and indoors, respectively. The outdoor levels reported to be 19 times higher than the outdoor concentrations during warmer months (summer + spring), while the indoor concentrations were suggested to be 9 times and 10 times higher than that for indoor summer (average 11.73 ± 4 ng m(-3)) and indoor spring (9.5 ± 3.3 ng m(-3)). During nighttime, outdoor PAHs revealed wider range of values compared to datytime which was likely due to outdoor temperature, a weather parameter with the strongest negative influence on ∑16PAHs compared to low impact of relative humidity and wind speed.


Assuntos
Poluentes Atmosféricos/análise , Poluentes Atmosféricos/toxicidade , Hidrocarbonetos Policíclicos Aromáticos/análise , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Poluição do Ar em Ambientes Fechados/análise , China , Cidades , Temperatura Baixa , Monitoramento Ambiental , Humanos , Tamanho da Partícula , Material Particulado/análise , Material Particulado/toxicidade , Medição de Risco
17.
J Chin Med Assoc ; 68(2): 65-72, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15759817

RESUMO

BACKGROUND: This study was designed to compare the efficacy and safety of thymosin-alphal (T-alpha1) with that of interferon-alpha (IFN-alpha) in patients with chronic hepatitis B who were positive for hepatitis B virus (HBV) DNA and hepatitis B envelope antibody (anti-HBe). METHODS: Fifty-six patients were randomly divided into groups A and B. Both groups were comparable (p > 0.05) at baseline regarding age, sex, and alanine aminotransferase (ALT) levels. Group A patients received T-alpha1 1.6 mg subcutaneously twice weekly, while group B patients received IFN-alpha 5 million IU daily for 15 days, then thrice weekly for 6 months. Results from the 2 groups were compared with data from a group of 30 patients never treated with IFN-alpha and who were followed-up for 12 months (historical control [HC] group); the 3 groups were comparable (p > 0.05). RESULTS: After treatment, a complete response (ALT normalization and HBV DNA loss) occurred in 8 of 26 patients in group A (30.8%) and 14 of 30 in group B (46.7%; chi2 = 1.476, p = 0.224). After a follow-up period of 6 months, a complete response was observed in 11 of 26 patients in group A (42.3%) and 7 of 30 in group B (23.3%; chi2 = 2.299, p = 0.129). The rate of complete response was significantly greater in the IFN-alpha than HC group at the end of therapy (46.7% vs 3.3%; chi2 = 15.022, p = 0.0001), and in the T-alphal than HC group at the end of follow-up (42.3% vs 3.3%; chi2 = 12.566, p = 0.0001). Ten of the 12 T-alphal responders (i.e. partial responders; 83.3%) experienced sustained, non-detectable HBV DNA after 6 months' treatment; 6 of the 14 T-alphal non-responders (42.9%) showed a delayed response of non-detectable HBV DNA during the follow-up period. Corresponding values for group B patients were 50% (9/18) and 0% (0/12). The rate of delayed response was significantly higher in group A than the other 2 groups (chi2 = 6.686, p = 0.010; chi2 = 4.964, p = 0.038), whereas the rate of flare was higher in group B than in the other 2 groups (chi2 = 3.445, p = 0.063; chi2 = 7.668, p = 0.006), during the follow-up period. Unlike IFN-alpha, T-alphal was well tolerated, i.e. no adverse effects were noted in group A. CONCLUSION: These results suggest that a 6-month course of T-alpha1 therapy is effective and safe in patients with anti-HBe-positive chronic hepatitis B; T-alpha1 can reduce HBV replication in such patients. Compared with IFN-alpha, T-alpha1 is better tolerated and seems to induce a gradual and more sustained normalization of ALT and loss of HBV DNA. Combination therapy with T-alpha1 and IFN-alpha or nucleoside analogs for hepatitis B warrants further study.


Assuntos
Hepatite B Crônica/tratamento farmacológico , Interferon-alfa/uso terapêutico , Timosina/análogos & derivados , Timosina/uso terapêutico , Adjuvantes Imunológicos/uso terapêutico , Adulto , Alanina Transaminase/efeitos dos fármacos , Alanina Transaminase/metabolismo , Antivirais/uso terapêutico , DNA Viral/metabolismo , Feminino , Antígenos da Hepatite B/imunologia , Antígenos de Superfície da Hepatite B/imunologia , Vírus da Hepatite B/efeitos dos fármacos , Vírus da Hepatite B/genética , Vírus da Hepatite B/imunologia , Humanos , Masculino , Pessoa de Meia-Idade , Timalfasina , Resultado do Tratamento
18.
Environ Pollut ; 197: 68-75, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25497308

RESUMO

Heavily-polluted PM2.5 (fine particulate matter) episodes frequently impacting Beijing, especially during winter, have become a substantial concern. We found that during winter, the daily variation of PM2.5 in Beijing tracked the pattern of relative humidity (RH). With the increase of PM2.5 (or RH), water-soluble components (especially inorganic ions) became more abundant, and the water-soluble organic carbon to organic carbon ratios increased. The nitrate to sulfate ratios also exhibited dependence on RH, and were higher than those measured about a decade ago, consistent with the increasing trend of nitrogen oxides emissions. Surprisingly, the ratios of water-insoluble organic carbon to elemental carbon showed significant increase at high RH levels, presumably indicating the formation of secondary organic aerosol that is not soluble in water. In addition, humid winters were occasionally identified during 1996-2013 which are expected to be favorable for the formation of air pollution episodes with high PM2.5 concentrations.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental , Umidade , Material Particulado/análise , Aerossóis/análise , Poluição do Ar/estatística & dados numéricos , Carbono/análise , China , Cidades , Íons/análise , Nitratos/análise , Tamanho da Partícula , Estações do Ano , Água
19.
Huan Jing Ke Xue ; 36(11): 3935-42, 2015 Nov.
Artigo em Zh | MEDLINE | ID: mdl-26910976

RESUMO

Based on the newly established high-performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD), the saccharides in PM2.5 and PM10 in Beijing from 2011 - 2012 were quantified. Fourteen saccharides were synchronously detected in the aerosols samples in Beijing, which can be divided into three categories, i. e. anhydrosugar, sugar and sugar alcohol. Anhydrosugar, coming from biomass burning, include levoglucosan, mannosan and galactosan. Sugar and sugar alcohol, emitted by the primary biogenic emission, include glucose, fructose, trehalose, arabitol, mannitol, glycerol, threitol, 2-meythltrtols (2-methylthreitol and 2-methylerythrito), xylitol and inositol. The concentrations of monosaccharide anhydrides in summer and autumn were obviously higher than those in spring and winter, while the concentrations of sugar and sugar alcohol in winter were significantly lower than those in other seasons. The results of positive matrix factorization analysis suggested that saccharides compounds in atmospheric PM in Beijing can be derived from biomass burning, suspended soil or dust, isoprene SOA, as well as direct release of airborne fungal spores and pollen.


Assuntos
Poluentes Atmosféricos/análise , Carboidratos/análise , Material Particulado/análise , Aerossóis , Pequim , Poeira , Monitoramento Ambiental , Galactose/análogos & derivados , Glucose/análogos & derivados , Manose/análogos & derivados , Estações do Ano , Álcoois Açúcares
20.
J Environ Sci (China) ; 16(5): 813-5, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15559818

RESUMO

A simple, sensitive and convenient ion chromatography(IC) method was established for the simultaneous determination of twelve water-soluble inorganic anions(F- , Cl- , NO2(-), NO3(-), SO3(2-), SO4(2-) , PO4(3-)), and fifteen water-soluble organic ions(formate, acetate, MSA, oxalate, malonate, succinate, phthalates, etc.) in atmospheric aerosols. The linear concentrations ranged from 0.005 microg/m3 to 500 microg/m3 ( r = 0.999-0.9999). The relative standard deviation (RSD) were 0.43%-2.00% and the detection limits were from 2.7 ng/m3 to 88 ng/m3. The proposed method was successfully applied to the simultaneous determination of those inorganic ions and organic ions in PM2.5 of Beijing.


Assuntos
Aerossóis/análise , Atmosfera/análise , Cromatografia por Troca Iônica/métodos , Íons/análise , Poluentes Atmosféricos/análise , China , Monitoramento Ambiental/métodos , Estudos de Viabilidade
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