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Peripheral sensory blockage for soreness manage inside individuals undergoing percutaneous angioplasty regarding complicated infrapopliteal condition.
rmation, low cost, but required too much time, which needs to be weighed and balanced before selecting this method. The AR method had strict requirements for equipment and parameters and should be used with caution. The results of this study can provide a comprehensive and detailed scientific basis for researchers to choose specific methods in the future.In order to explore the influence of polycyclic aromatic hydrocarbons (PAHs) emissions by petrochemical enterprises on the surrounding environment, atmospheric deposition samples of the PAHs were collected in the industrial and residential areas adjacent to a petrochemical enterprise from March 2017 to February 2018. Deposition fluxes and the composition of PAHs were studied. The source of PAHs was analyzed by a positive matrix factor (PMF) model. The results showed that the deposition fluxes of Σ15 PAHs ranged from 549 ng·(m2·d)-1 to 18845 ng·(m2·d)-1, with an average of 2712 ng·(m2·d)-1. The flux of Σ15 PAHs in the industrial area was 1.36 times greater than that in the residential area. The deposition fluxes of PAHs in winter and spring were higher than those in summer and autumn. The deposition flux was highest in January in the industrial area and lowest in October in the residential area. Phe, BbF, and Fla were the dominant monomers. There was noticeable difference of monomers between the industrial are significantly reduced.Based on the monitoring data of the Guangdong-Hong Kong-Macao Pearl River Delta Regional (PRD) Air Quality Monitoring Network from 2006 to 2019, the ozone trend in RRD was analyzed using the Mann-Kendall test method, Sen's slope method, and the Pettitt change point test. The results show that① the average ozone concentration in the PRD has increased significantly from 2006 to 2019 (P less then 0.05), with an average growth rate of 0.80 μg·(m3·a)-1. After 2016, the rate of ozone increase has accelerated. ② The average annual ozone concentration in the central PRD increased significantly, while in the peripheral areas of the PRD, this is not obvious. Ozone increases significantly in summer but not in other seasons.③ From 2006 to 2019, the concentration of NO2 in the central PRD decreased remarkably, so the titration effect weakened and resulted in an increase in the ozone concentration. The concentration of NO2 in the marginal areas of the PRD has little change, so the ozone concentration in these areas has little change. ④ With the changes of VOCs and NO2 concentrations, the chemical sensitivity of O3 production in the PRD is changing. The VOC-limited regimes are continuously decreasing, and the mixed NO x -VOC-limited regimes and NO x -limited regimes are increasing. In order to deal with regional ozone pollution, the cooperative control of VOCs and NO x needs to strengthen.In this study, the 24-hour backward trajectories of air mass at ground level(10 m)in Nanjing were calculated by using the HYSPLIT model with the NCEP global reanalysis data from April 1st to October 31st, 2017. The backward trajectories were then combined with the hourly concentration data of O3 in Nanjing for trajectories clustering analysis and potential pollution sources analysis. The results show that in 2017, the maximum daily 8 h running average O3 level in Nanjing was around 12-261 μg·m-3 with 58 days of O3 pollution in Nanjing, mainly in the spring and summer. The monthly variation of O3 showed a single peak, with the highest O3 concentration, as well as the most days exceeding the standard, occurring in June; the diurnal variation of O3 was unimodal and reached its peak around 1400. A total number of 5136 trajectories were obtained by simulation, among which the exceeded trajectories accounted for approximately 10%. The exceedance trajectories in May and June were significantly higher, accounting for 60% of the total exceedance trajectories. Six ground-level air mass transporting pathways were identified through clustering analysis, from the NNE, NW, SW, SSE, SE, and NE directions. The SE and SSE directions with higher O3 levels were the dominant transport routes of O3 pollution, contributing to 23.33% and 20.76% of backward trajectories, respectively. As for the potential pollution source analysis, the area with high WCWT value distribution matched the WPSCF result, indicating that the potential sources of O3 pollution were mainly distributed in Changzhou, Wuxi, Suzhou, Huzhou, and other cities around Taihu Lake. Additionally, cities located around Nanjing, such as Taizhou, Ma'anshan, Wuhu, Chuzhou, Nantong, and Lianyungang, were considered the secondary potential sources. The results indicate that O3 pollution in Nanjing is a regional issue and its control requires joint prevention and control strategies in the Yangtze River Delta.From June to August 2018, a 1-hr resolution concentration dataset of ozone and its gaseous precursors (volatile organic compounds(VOCs) and NO x ), and meteorological parameters were synchronously monitored by online instruments of the Nankai University Air Quality Research Supersite. The relationships and variation characteristics between ozone and its precursors were analyzed. According to the photochemical age, the initial concentrations of VOCs were calculated, and the photochemical loss of the concentration of VOCs during the daytime (0600-2400) was corrected. The initial and directly monitored concentrations of VOCs were incorporated into the PMF model for source apportionment. The results indicated that the mean concentration of O3 in Tianjin in summer was (41.3±25.7)×10-9, while that of VOCs was (13.9±12.3)×10-9. The average concentration of alkane (7.0±6.8)×10-9 was clearly higher than that of other VOC species. The species with high concentrations of alkanes were propane and ethane, accounting for 4directly monitored concentrations, the OFP values of the chemical industry and solvent usage decreased by 7%, while that of NG/LPG apparently decreased by 13%.The objective was to investigate the characteristics and sources of ambient volatile organic compounds (VOCs) in the karst region in southwestern China. We monitored atmospheric VOCs in Liuzhou by the GC955 VOCs Online Monitoring System and analyzed the pollution characteristics, ozone formation potential (OFP), aerosol formation potential (AFP), and the positive matrix factorization (PMF) model in March 2019. The results show that ① 50 kinds of VOC components were detected during the supervised period, with an average daily concentration of 25.52×10-9 mol·mol-1, which was composed of alkanes (56.08%), alkenes (19.63%), alkynes (14.25%), and aromatics (10.04%), respectively. ② The concentration of VOCs was lower during the day and higher at night, with the highest value at 2300. The VOC concentration was low in daytime and high at night. The peak value of VOCs with regard to diurnal variation was correlated with the time of morning and the evening traffic peak and may be influenced by various factors. ③ The cnd aromatic hydrocarbons emitted by these emission sources should be mainly considered.The characterization and source apportionment of atmospheric volatile organic compounds (VOCs) in Tianjin in 2019 were investigated based on high-resolution online monitoring data observed at an urban site in Tianjin. The results showed that the average annual concentration of VOCs was 48.9 μg·m-3, and seasonal concentrations followed with winter (66.9 μg·m-3) > autumn (47.9 μg·m-3) > summer (42.0 μg·m-3) > spring (34.6 μg·m-3). The chemical compositions of the VOCs were alkanes, aromatics, alkenes, and alkynes, which accounted for 65.0%, 17.4%, 14.6%, and 3.0% of the VOCs concentrations on average, respectively. The proportion of alkanes, aromatics, and alkynes was the highest in autumn, summer, and winter, respectively, while a higher alkenes proportion was observed in summer and winter. The ozone formation potential contribution of alkanes, alkenes, aromatics, and alkynes in spring and summer was 16.9%, 48.6%, 33.5%, and 1.0%, respectively, and the species with higher contributions were ethene, propylene, and summer, a significant increase was observed for LPG/NG and combustion emission of 62.8% and 153.4%, respectively, and other sources decreased by 18.4%-25.0% in autumn and winter. Source composition spectrums showed that the petrochemical industry and solvent usage were the main emission sources of alkenes and aromatics in spring and summer, and combustion and solvent usage were the main emission sources of aromatics in autumn and winter. Ipatasertib order Thus, focus should be played on the petrochemical industry and solvent usage in spring and summer and on combustion and solvent usage in autumn and winter to further prevent and control ozone and SOA in Tianjin.Ambient carbonyl compounds play an important role in tropospheric atmospheric chemistry. Primary emissions and photochemical formation are both sources of carbonyls, and therefore it is challenging work to analyze their sources. In this study, carbonyl sources were apportioned using the source tracer ratio method (STR) and positive matrix factorization model (PMF) based on offline carbonyls observations at a site in Nanjing during March 2017. Eleven carbonyl compounds were detected, and their total concentrations were in the range of 2.57×10-9-22.83×10-9. Formaldehyde, acetaldehyde, and acetone were the main components, accounting for 36.8%, 21.6%, and 18.5% of the average concentration of eleven carbonyl compounds, respectively. The influences of tracer selection and background concentrations on the results of source apportionment using the STR method based on comparing the results of acetylene and toluene as tracers and the 5th and 10th percentages as background concentrations are presented. Five sources were resolved by PMF, including traffic emission, the petrochemical & chemical industry, paint & solvent use, secondary formation & background, and the chemical industry. Secondary formation & background sources were the largest contributors of carbonyl compounds, contributing 56.4%, 48.2%, and 58.3% to formaldehyde, acetaldehyde, and acetone, respectively. By comparing the carbonyl source apportionment results by STR and PMF, it was found that the STR depends on the selection of tracers. When the STR is applied in the areas with complex sources, it is difficult to use a tracer to indicate anthropogenic source emissions, and therefore it is not a suitable method for carbonyl source apportionment.To reveal the pollution characteristics and the health risks of the trace heavy metals in the atmospheric particles in Baoding, Hebei province, PM2.5 samples were collected using a middle volume sampler, and the mass concentrations of V, Cr, Mn, Co, Ni, Cu, Zn, As, Cd, and Pb in the samples were determined by microwave digestion-inductively coupled plasma-mass spectrometry (ICP-MS). The results showed that the PM2.5 concentration in Baoding ranged from 16.84-476.2 μg·m-3. During sampling, 65 samples were above the second-level standard of the Ambient Air Quality Standards (GB 3095-2012) by 54.2%. The most heavy metal elements showed higher levels in nighttime than during the daytime, except for except for Ni, Mn, and Co. Obvious seasonal variation was found with the trend of winter > autumn > spring > summer. The enrichment factors for Cu, Zn, Pb, and Cd were more than 1.5, indicating that those metals mainly came from anthropogenic emissions, such as traffic sources. Health risk assessment results indicated that the non-carcinogenic risk of heavy metals in PM2.
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