[Concentration and Reactivity of Carbonyl Compounds in the Atmosphere of North China].

To reveal the characteristics of photochemical pollution in North China, adsorbing columns with 2, 4-dinitrophenylhydrazine(DNPH) were used to sample carbonyl compounds in Shijiazhuang and Xinglong between May 2018 and April 2019. The samples were analyzed by high-performance liquid chromatography to understand the composition, volume fraction, source, ·OH loss rate, and ozone formation potential of the carbonyl compounds. A total of 13 carbonyl compounds containing carbonyl groups were determined, of which acetone, formaldehyde, and acetaldehyde were highest at(6.46±5.25)×10-9, (3.76±2.29×10-9), and(2.65±1.74)×10-9 in Shijiazhuang compared to(1.85±1.27)×10-9, (1.29±1.02)×10-9, and(0.72±0.48)×10-9 in Xinglong, respectively. The estimated maximum ozone formation potential(OFP) of formaldehyde was much higher than that of acetaldehyde; the C1/C2 and C2/C3 ozone formation potential(OFP) of formaldehyde was much higher than that of acetaldehyde; and the C1/C2 and C2/C3 values showed that vehicle exhaust and fossil fuel combustion were the main sources in Shijiazhuang in association with the higher level of industrialization. In Xinglong, the carbonyl compounds mainly originated from natural sources. Acetaldehyde(1.77 s-1), formaldehyde(1.57 s-1), and butyraldehyde(0.42 s-1) contributed most to L·OH in Shijiazhuang, and formaldehyde(0.53 s-1), acetaldehyde(0.47 s-1), and butyraldehyde(0.12 s-1) were the three main contributors to L·OH in Xinglong. The carbonyl compounds contributing most to O3 production were formaldehyde and acetaldehyde at(34.61×10-9 O3) and (16.73×10-9 O3) in Shijiazhuang, compared to (11.77×10-9 O3) and (4.47×10-9 O3) in Xinglong, respectively.

[Chemical Composition and Source Analysis of PM2.5 in Yuncheng, Shanxi Province in Autumn and Winter].

In order to reveal the chemical composition characteristics and pollution sources of fine particulate matter (PM2.5) in autumn and winter in Yuncheng, PM2.5 samples were continuously collected using a four-channel small-flow particulate sampler from October 15, 2018 to March 15, 2019. The study prediminantly analyzed the chemical components of water-soluble ions, elemental carbon, organic carbon, and metal elements. Additionally, the chemical mass reconstruction method of particulate matter and the positive matrix factorization model (PMF) were combined for an in-depth discussion. During the sample period, the PM2.5 mass concentrations range was 29.37-370.11 µg·m-3, and 101 days during the sampling period exhibited concentrations that were higher than the secondary standard in China's Ambient Air Quality Standards (GB 3095-2012), with an exceeding rate of 70.63%. These results indicate that the air pollution in Yuncheng in autumn and winter is serious. According to the air quality index (AQI), the collected samples are classified as clean, light-moderate pollution, and heavy-severe pollution. Water-soluble ions, OC, EC and metal elements account for 40%, 19%, 5%, and 7% on clean days, 46%, 18%, 4%, and 5% on days with light-moderate pollution, and 46%, 21%, 4%, and 4% on days with heavy-severe pollution, respectively. Secondary ions NO3-, SO42-, and NH4+ are the primary components of water-soluble ions, accounting for 81% (clean days), 87% (light-moderate pollution), and 87% (heavy-severe pollution) of the total ion concentration, respectively. The OC/EC ratios during the sampling period were 3.78 (clean days), 4.02 (light-moderate pollution), and 5.37 (heavy-severe pollution). With the intensification of pollution, the pollution of secondary organic aerosols in the atmosphere becomes increasingly serious. In addition, as the air pollution increased, the concentration of Fe and Cr elements gradually decreased, while the concentration of other metal elements showed an overall upward trend. The results of the chemical mass reconstruction demonstrate that among the different pollution levels of atmospheric PM2.5 in Yuncheng, the mass percentages of secondary inorganic salt, sea salt, heavy metals, mineral dust, construction dust, organic matter, and elemental carbon were 36%, 2%, 2%, 8%, 1%, 33%, and 5% (clean days), 41%, 1%, 1%, 5%, 0.01%, 31%, and 5% (light-moderate pollution), and 41%, 1%, 1%, 4%, 0.004%, 34%, and 4% (heavy-severe pollution). The proportion of secondary inorganic ions increased and mineral dust decreased with the deterioration of air quality. The PMF analysis results suggest that secondary related sources, coal combustion sources, vehicle exhaust sources, biomass burning, and secondary organic matter are the predominant sources of PM2.5 during serious air pollution in Yuncheng.

[Pollution Characteristics and Health Risk Assessment of Heavy Metals in PM2.5 Collected in Baoding].

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 PM2.5 in Baoding was small, and the carcinogenic risk resulting form As, Cr, Cd, and Co was greater for adults than for children.

[Pollution Characteristics and Source Apportionment of n-Alkanes and PAHs in Summertime PM2.5 at Background Site of Yangtze River Delta].

To investigate the pollution characteristics and sources of organic aerosols at a background site of the Yangtze River Delta, day- and night- PM2.5 samples were collected from May 30th to August 15th, 2018 in Chongming Island, China and measured for their normal alkanes (n-alkanes) and polycyclic aromatic hydrocarbons (PAHs) content employing a GC-MS technique. Concentrations of PM2.5, n-alkanes, and PAHs during the entire sampling period were (33±21) µg·m-3, (26±44) ng·m-3, and (0.76±1.0) ng·m-3, respectively. During the entire campaign, 35% of the collected PM2.5 samples were of a particle loading larger than the first grade of the China National Air Quality Standard (35 µg·m-3), suggesting that further mitigation with respect to air pollution in Chongming Island remains imperative. In the period with a PM2.5 concentration higher than 35 µg·m-3, which was classified as the pollution period, concentrations of n-alkanes and PAHs were one order of magnitude higher than those in the period with PM2.5 less than 15 µg·m-3, which was classified as the clean period. During the entire campaign, OC was higher in the daytime than in the nighttime, mainly due to the daytime photooxidation that enhanced the formation of secondary organic aerosols. During the pollution period, concentrations of EC and other pollutants were higher in the nighttime than in daytime, mainly due to the transport of the inland pollutants by the nighttime land breeze. Such a diurnal difference was not observed for the pollutants in clean periods, mainly due to the relatively clean breeze from East China Sea that diluted the air pollution. Diagnostic ratios showed that 67% of n-alkanes in PM2.5 was derived from fossil fuel combustion. PMF analysis further showed that during the pollution period, vehicle exhausts and industrial emissions were the largest sources of PAHs, both accounting for 51% of the total in PM2.5. In contrast, during the clean periods ship emissions were the largest source, contributing about 45% of the total PAHs, exceeding the sum (38%) of vehicle and industrial emissions.

[Pollution Characteristics and Source Analysis of Aromatic Compounds in Shijiazhuang].

To understand the pollution characteristics of aromatic compounds in Shijiazhuang, PM2.5 samples were collected day and night for 30 days from September 18 to October 17, 2016. Qualitative and quantitative analyses were conducted using gas chromatography-mass spectrometry (GC-MS). The results showed that total average concentration of aromatic compounds was 33.5 ng·m-3, lower than that of levoglucosan (487 ng·m-3). Concentration of nitro-aromatic compounds was the highest (20.4 ng·m-3), followed by aromatic acids (9.94 ng·m-3) and aromatic aldehydes (3.14 ng·m-3). Influenced by the decrease in the boundary layer and temperature, concentration of 8 substances during night was higher than during the day. There was a significant positive correlation between levoglucosan and nitro-aromatic, aromatic aldehyde, and aromatic acid compounds, with correlation coefficients (r) of 0.6829, 0.6443, and 0.6782, respectively, indicating that biomass burning is an important primary source of aromatic compounds that directly affects their concentrations in the atmosphere. Based on the analysis of daily variation trends in total concentration of aromatic compounds and the backward trajectory model, it was found that the pollution of aromatic compounds in Shijiazhuang in autumn was affected by regional transportation and local emissions.

[Concentration and Ecological Risk Assessment of Heavy Metals in PM2.5 Collected in Urban and Suburban Areas of Beijing].

Atmospheric PM2.5 pollution and ambient air quality were investigated in Beijing, and the ecological risks of the trace heavy metals in PM2.5 were analyzed. PM2.5 samples were collected from Dongzhimen and Huairou by a middle volume sampler, and 16 kinds of trace metals were determined by inductively couple plasma-mass spectrometry (ICP-MS). The results showed that the average concentration of PM2.5 in the urban area was 92.35 µg·m-3, and the number of days higher than the Ambient Air Quality Standards (GB 3095-2012) accounted for 41.7% of the total number of days. The average concentration of PM2.5 in the suburban area was 70.90 µg·m-3, and the standard exceedance rate was 31.7%. In general, the spatial and temporal distributions of heavy metals were as follows:nighttime > daytime; urban area > suburban area; winter > autumn > spring > summer. The enrichment factors for Pb, As, Zn, Ni, and Cu in the urban area and Pb, As, Zn, Cr, Ni, and Cu in the suburban area indicated that most came from anthropogenic sources. The result for the geoaccumulation index indicated that Ni is affected by anthropogenic sources and natural resources, while Cu, Zn, As, Cd, and Pb might have been derived from human activities. The potential ecological risk of Cu, Zn, Pb, and Cd was high, while the degree of ecological harm posed by Cd was extremely strong.

Evolution of aerosol chemistry in Xi'an during the spring dust storm periods: Implications for heterogeneous formation of secondary organic aerosols on the dust surface.

TSP and 9-stage size-segregated samples were simultaneously collected in Xi'an during the spring of 2013 and analyzed for organic aerosols (OA) on a molecular level. n-Alkanes were the dominant compound class during the whole campaign, followed by fatty acids. High molecular weight (HMW) n-alkanes and fatty acids dominated in the coarse mode particles (>1.1 µm) during the dust event, indicating they were mostly originated from surface soil and plants in the upwind regions. Low-volatile anthropogenic compounds such as benzo(e)pyrene (BeP) and bisphenol A (BPA) dominated in the fine mode particles during the whole campaign. In contrast, semi-volatile anthropogenic compounds such as phenanthrene (Phe) and di-n-butyl phthalates (DBP) showed a bimodal size distribution with a significant increase in the coarse mode during the dust event due to their vaporization from the fine mode particles and the subsequent adsorption on the dust surface. Secondary organic aerosols (SOA) in Xi'an during the dust storm period were predominantly enriched on the coarse particles, which can be ascribed to the adsorption and subsequent oxidation of gas-phase hydrophilic organics on the aqueous-phase of hygroscopic dust surface (e.g., mirabilite). Our work suggested an important role of multiphase reaction in evolution of aerosol chemistry during the dust long-range transport process.

[Analysis of Different Particle Sizes, Pollution Characteristics, and Sources of Atmospheric Aerosols During the Spring Dust Period in Beijing].

To understand the evolution of the physical and chemical properties of dust aerosols in the atmosphere, the concentrations and chemical compositions of differently sized particles were continuously observed and analyzed using an ion chromatograph and carbonaceous analyzer during the outbreak of dust in May 2017 in Beijing. The concentrations of total suspended particulate (TSP), water-soluble organic carbon (WSOC), elemental carbon (EC), OC, and water-soluble inorganic ions were (2237.59±681.49), (29.90±18.05), (1.46±3.05), (67.35±29.07), and (136.75±46.38) µg·m-3 during the dust period, respectively, and significantly exceeded that of the non-dust period, except for EC. The Na+, NH4+, K+, Mg2+, Ca2+, Cl-, NO3-, SO42-, and WSOC concentrations during the dust storm period were 11.55, 3.00, 14.88, 14.89, 9.40, 4.60, 2.40, 3.91, and 1.83 times higher than that during the non-dust period. The growth of crustal ions, such as Ca2+ and K+, was notably the largest and NH4+ and NO3- were minimal. The size distribution indicates that crustal ions primarily occur in the coarse mode during the whole sampling campaign. The SO42- and NO3- ions are slightly bimodal during the dust storm, with a dominant peak in the coarse mode at 4.7-5.8 µm and a very minor peak in the fine mode with a size range of 0.43-0.65 µm. During the non-dust period, SO42- is the dominant mode in the fine mode, while NO3- changes little compared with that during the dust period, which indicates that heterogeneous reaction with crustal ions is the main formation mechanism of NO3- in the coarse mode. A significant positive correlation was observed between SO42- and the sum of crustal ions during the dust period, indicating that the source of SO42- during the dust period is remote transmission of the dust storm. During the non-dust period, the positive correlation of SO42- with NH4+ indicates that secondary formation is the main source of SO42-. Based on correlation analysis of NO3- with crustal ions and NH4+, both remote transmission and secondary formation are the sources of NO3- during the dust storm and heterogeneous reactions are predominant during the non-dust period.

[The change of patients' psychosomatic symptoms after orthognathic surgery].

PURPOSE: To assess the change of patients' psychological status before and after orthognathic surgery. METHODS: The psychological status in 36 patients were assessed before and after orthognathic surgery using the SCL-90 questionnaire. The patients were allowed to evaluate the changes of mastication, facial aesthetics, pronunciation and function of temporomandibular joint subjectively through the questionnaire. The data were analyzed using SPSS13.0 software package. RESULTS: Six factors including obsessive-compulsive symptoms, interpersonal sensitivity, depression, anxiety, phobic anxiety and psychoticism were significantly higher than norm preoperatively. No obvious abnormalities were found 2 years after operation. The self-evaluated quotas by patients after operation were significantly improved compared with those preoperatively. CONCLUSIONS: The patients' psychosomatic symptoms are significantly improved after operation. No significant difference is found compared with ordinary people concerning psychological health.

[Observation of size distribution of atmospheric OC/EC in Tangshan, China].

Atmospheric particulate matter pollution is serious in Tangshan, a heavy industrial city of North China. The annual average concentrations of PM1.1, PM2.1, PM9.0 and TSP were (75 +/- 43), (106 +/- 63), (221 +/- 100) and (272 +/- 113) microg x m(-3), respectively, from 2009 to 2011. Carbonaceous aerosols were the key components in various size particles. Elemental carbon (EC) accounted for 9%, 9%, 6% and 4% of PM1.1, PM2.1, PM9.0 and TSP, respectively, meanwhile, organic carbon (OC) accounted for 25%, 24%, 16% and 14% of PM1.1, PM2.1, PM9.0 and TSP, respectively. The concentration spectrum distribution of particulate matter and the enrichment amount of the carbonaceous aerosols showed seasonal variations. In autumn and winter, the EC and OC concentration in the fine particulate matter reached up to (9 +/- 4), (11 +/- 5) and (19 +/- 7), (28 +/- 10) microg x m(-3), respectively, accounting for 11%, 10% and 26%, 25% of fine particles; EC and OC in spring and summer were (5 +/- 2), (5 +/- 1) and (15 +/- 3), (15 +/- 1) microg x m(-3), respectively, accounting for about 7%, 6% and 26%, 18% of TSP, respectively.

[Water-soluble inorganic salts in ambient aerosol particles in Tangshan].

To investigate the levels, seasonal variation and size distributions of water soluble inorganic components, samples were collected with an Andersen cascade sampler in Tangshan from Sep. 2010 to Aug. 2011, and were analyzed by IC. The results showed that the secondary inorganic components (SO4(2-), NO3(-) and NH4(+)) were the major contributors to PM9 and PM2.1, accounting for 68% and 77% of the total water soluble salts in PM9 and PM2.1, respectively. The total concentrations of these three ions in spring, summer, autumn, and winter were 35.0, 84.7, 67.3 and 61.6 microg x m(-3) in PM9, and 23.2, 64.8, 52.7 and 49.6 microg x m(-3) in PM2.1. About 70%, 75% and 94% of SO4(2-), NO3(-) and NH4(+) were found in the fine mode of aerosol, respectively. Ca2+ and Mg2+ were unimodal and mostly concentrated in the coarse mode. Those results indicated that the pollution caused by atmospheric particles is serious in Tangshan. It is urgent to control the anthropogenic emissions sources, such as vehicle emission, coal and biomass burning. Meanwhile, it is necessary to strengthen the greening and reinforce the management of the road construction.

[Pollution characteristics and source identification of atmospheric particulate matters n-alkanes in Baoding City].

Organic matter has been a very important component in the ambient particulate matter of big cities in China. In order to investigate the mass concentrations and sources of the organic matter which are adsorbed in ambient particulate matters in the industry cities of Hebei province, aerosol samples were collected with Anderson sampler during Sep. 2009 to Aug. 2010, in Baoding city, Hebei province. The concentration of n-alkanes was determined via GC-MS. About 66.7% of the daily average concentrations of fine particulate matters were higher than the 24-hour average threshold value of class II standard of the ambient air quality standard (GB 3095-2012, 75 microg.m-3). About 96% of the daily average concentrations of inhalable particles were higher than 150 microg.m-3)(GB 3095-2012). The total concentration of n-alkanes was in the range of 111.23-979.81 ng.m-3 with an average of 264.2 ng.m-3. The n-alkene homologues from C14 to C32 were detected with different peak carbon numbers ranging from 20 to 27 in different seasons. In summer, the peak carbon number was 27, while it was C20, C21 or C22 in winter and spring. The CPI values were 0. 97, 1. 24, 0. 92 and 0. 86 in spring,summer, autumn and winter, respectively, with an average of 1.01. These results indicated that the incomplete combustion of fossil fuel and vehicle emissions was the main resource of n-alkanes in winter and spring, and the high plant waxes were playing a major role in summer and autumn. The primary sources were anthropogenic activities all year round.

[Analysis on water-soluble inorganic ions in the atmospheric aerosol of Xinglong].

Size-segregated aerosol samples were collected using Andersen cascade sampler from Sep. 2009 to Aug. 2010 in Xinglong, a regional atmospheric background station. The water-soluble inorganic ions were analyzed by IC. The result showed that the annual concentrations of the total water-soluble inorganic ions were (89.66 +/- 47.66), (54.44 +/- 34.08) and (44.39 +/- 29.95) microg x m(-3) in TSP, PM2.1 and PM1.1 respectively. SO4(2-), NO3(-), Ca(2) and NH4(+) were the dominant contributors of water-soluble inorganic ions. The total water-soluble inorganic ions in PM2.1 accounted for 61% of TSP. The total water-soluble inorganic ions in PM1.1 accounted for 50% and 82% in TSP and PM2.1, respectively. The seasonal variations of the total water-soluble inorganic ion concentration in TSP, PM2.1 and PM1.1 were the same, following the order of summer > autumn > springs > winter. The mean molar ratio of NH4(+) to SO4(2-) was larger than 2, indicating that NH4(+) was not completely neutralized by SO4(2-). NH4(+) -SO4(2-) and NH4(+) -NO3(-) concentrations were strongly correlated (R2 0.96 and 0.87), indicating that NH4(+) was mainly present as (NH4) 2SO4 and NH4NO3.

[Chemical characteristics and sources of trace metals in precipitation collected from a typical industrial city in Northern China].

To investigate the chemical characteristics and possible sources of trace metals in precipitation of Tangshan, a typical industrial city in Northern China, precipitation samples were collected using an automated wet-only sampler for one year from December 2009 to November 2010 and subjected to chemical analysis using ICP-MS. The results showed that crustal elements (Ca, Mg, Na, K, Fe and Al) accounted for 97.72% of the total concentrations while heavy metals (Zn, Mn, Pb, Ba, Sb, Cu, Ni, As, V, Co and Se) only contributed 2.25% of the total. Zinc was the most abundant heavy metal and calcium had the highest concentration among the crustal elements, with volume-weighted mean concentrations of 88.7 microg x L(-1) and 4.5 mg x L(-1), respectively. Seasonal variations of trace metals were significant, with higher values observed in winter and spring than in summer and autumn. The calculation of crustal enrichment factors with Al as the reference element indicated that Tl, As, Ag, Zn, Pb, Cd, Se and Sb were mainly derived from anthropogenic sources and the enrichment factor values of those elements ranged from 10(2) to 10(5). In addition, the concentrations of heavy metals such as Pb, Cu and Ni in precipitation of Tangshan city were higher than those reported for Mt. Tai. The results of principle component analysis demonstrated that steel smelting emissions, fugitive dusts and coal combustion were probably the major contributors of trace metals in the precipitation of Tangshan City.

[Chemical composition and mass closure of particulate matter in Beijing, Tianjin and Hebei megacities, Northern China].

To seek an efficient prevention and control method of regional atmospheric pollution in Jingjinji area, mass concentrations and size-resolved chemical composition of particulate matter were investigated at four urban sites and one background site from June 2009 to May 2010. The results show that the annual mean concentration of PM10 was 124, 141, 151 and 183 microg x m(-3) in Beijing, Tianjin, Tangshan and Baoding respectively, while the corresponding percentage of daily limit value exceedances was 29%, 36%, 39% and 52%, which is well above the maximum allowed limit of 150 microg x m(-3) (National Air Quality Stand II). As for PM2.5, the annual average concentration was 55, 68, 79 and 116 microg x m(-3) in Beijing, Tianjin, Tangshan and Baoding, which is higher than that in the background site with a factor of 1.5, 1.9, 2.2 and 3.2, respectively, while the corresponding proportion of daily exceedances of 75 microg x m(-3) (WHO IT-1) was 29%, 33%, 42% and 65%. Seasonal variations of PM2.5 and PM10 concentration were significant at the urban sites with the highest value being measured in winter. In order to reconstruct the particle mass, the determined components were classified into five groups as follows: secondary inorganic aerosol, sea salt, heavy metal, mineral matter and construction dust. The urban-sites-averaged contribution of these components to PM2.1 was 28.5%, 5.8%, 1.8%, 14.8% and 3.8%, whereas that to PM2.1-9 was 11.3%, 6.7%, 1.1%, 43.5% and 7.6%, respectively. The particle pollution was very severe in Baoding with the major component of secondary inorganic aerosol and mineral matter in PM2.1 and PM2.1-9, respectively. The estimated contribution of anthropogenic sources to PM2.1 in Beijing was larger than that of natural sources with a factor of 3.5 whereas the ratio of anthropogenic sources to natural ones was 0.6 for PM2.1-9. The contribution of secondary components to PM2.1 was equivalent to primary emissions, which suggests the precursors emitted from coal combustion and vehicle exhaust should be controlled in the target area. In contrast, the ratio of primary emissions to secondary particulate matters in PM2.1-9 was up to 5, indicating measures are required to reduce dust from construction areas. Finally, the reduction of human health-related heavy metals is also necessary despite its minor contribution to particles.

[Size distribution and characterization of EC and OC in aerosols during the Olympics of Beijing, China].

Samples of airborne PM with different size were collected by cascade impactor (Andersen) in Beijing during the Beijing Olympics. Organic carbon (OC) and elemental carbon (EC) in particles were determined by DRI Model 2001 A t carbon analyzer of USA. PM (56%), OC (55%) and EC (73%) were associated with the fine particle below 2.1 microm. OC and EC account for 25% and 5% of particle below 2.1 microm, respectively, which indicates that carbonaceous aerosols are key components for controlling fine particles pollution in Beijing. It is found that Beijing auto measures were effective in abatement of carbonaceous aerosols. The ratios of OC/EC indicated that the main origins of carbonaceous aerosols in fine particle were automobile exhaust fumes and coal combustion and in coarse particle were biomass burning and cooking. The average percentage of estimated secondary OC (OC(sec)) in the total OC (OC(tot)) in TSP was 74%. The results of correlation analysis show that the correlation coefficient between the OC and secondary water soluble ions (SO4(2-), NO3-, NH4+, NO2-) were very high in PM2.1 (R2 = 0.88), while the correlation coefficient was very faint in particles greater than 2.1 microm (R2 = 0.21).

[Laryngeal function preserving surgery in hypopharyngeal carcinoma].

OBJECTIVE: To evaluate the preservation of laryngeal function hypopharyngeal cancer surgery clinical effectiveness and impact of prognostic factors. METHODS: A retrospective analysis in September 1974 - July 2003 treated 45 cases of hypopharyngeal cancer surgery retain the clinical treatment of laryngeal function effect. Among them there were 23 cases of original pyriform sinus cancer, 13 cases of post cricoid cancer and 9 cases of postero pharyngeal wall cancer. Two cases of preoperative radiotherapy, radiotherapy volume of 40-50 Gy; after 32 cases of radiotherapy, radiotherapy dose of 60-70 Gy. Analysis of impact on survival in patients with risk factors. RESULTS: Forty five cases of preservation of laryngeal function after 88.9% who articulate pronunciation ambiguities were mild 11.1%; 23 cases of tracheostomy tube removal, decannulation rate was 51.1%, all can eat into the cape. Nineteen cases of post-operative complications (42.2%); after 20 cases of cervical lymph node metastasis, accounting for 44.4%. Statistics Kaplan-Meier method in patients with the whole group 5-year survival rate was 53.3%. T1 + T2 and T3 + T4 patients after 5-year survival rates were 66.7% and 43.3%; cN0 and cN1, cN2 group survival rates were 65.2% and 46.7%, 28.6%; pathological differentiation of high, medium and low-group survival rates were 62.3%, 42.1% and 30.8%. Single-factor analysis of survival and whether pre-operative cervical lymph node metastasis and the degree of pathological differentiation (chi2 value of 5.297 and 11.556, P value of 0.021 and 0.003). Multivariate Cox regression analysis showed that the availability of pre-operative cervical lymph node metastasis and pathological effects of the degree of differentiation is an independent risk factor for prognosis (chi2 value of 4.365 and 4.600, P value of 0.041 and 0.032, OR value of 1.151 and 0.610). CONCLUSIONS: Preservation of laryngeal function hypopharyngeal cancer surgery for T1, T2 patients with the best surgical procedures, some of T3, T4 advanced hypopharyngeal cancer can also be used to retain the operation of laryngeal function; and preservation of laryngeal function can not affect the prognosis of patients with.

[Pollution characteristics of n-alkanes in atmospheric fine particles during Spring Festival of 2007 in Beijing].

Research PM2.5 aerosols had been carried out with sampler of high-volume sampler during Spring Festival of 2007 in Beijing, and the concentrations of n-alkane in PM2.5 samples were determined via GC-MS. The average concentrations of PM2.5 which were all exceeded WHO threshold values were higher in the night than those in the day time. The n-alkane homolog from C10 to C33 were detected with the major peak carbon numbers ranging from 23 to 25. The total concentrations of n-alkane were higher in the night (943.5 ng x m(-3)) than those in the day time (581.1 ng x m(-3)). And also we found that the average concentrations of n-allkane before New Year's Eve (1,025.5 ng x m(-3)) were higher than those after (536.6 ng x m(-3)). The CPI values were 0.9-1.4 with average of 1.15. Those results may mean that primary resource of n-alkane in fine particles was the incomplete combustion of fossil fuel. The percent contribution of leaf "Wax" n-alkane indicated that about 8.5%-47% of n-alkane came from waxy leaf surface abrasion.

[Pollution characteristic of PAHs in atmospheric particles during the Spring Festival of 2007 in Beijing].

Research on PM10, and PM2.5, aerosols had been carried out with sampler of large flow capacity during the Spring Festival of 2007 in Beijing, and the concentration of polycyclic aromatic hydrocarbons (PAHs) in PM2.5, samples were determined via GC-MS. The average concentrations of aerosols are higher in the night (PM10: 232 microg x m(-3); PM2.5: 132 microg x m(-3)) than those in the day time (PM10: 194 microg x m(-3); PM2.5: 107 microg x m(-3)). The average concentrations are higher after the new year's eve (PM10: 252.3 microg x m(-3), PM2.5: 123.8 microg x m(-3)) compared with those before (PM10: 166.7 microg x m(-3), PM2.5: 106.8 microg x m(-3)). And we also find that the concentration of PAHs in PM2.5 aerosols is generally higher in the night (106.4 ng x m(-3)) than that in the day time (44.2 ng x m(-3)), and the total concentration of 17 PAHs before new year's eve (95.9 ng x m(-3)) is higher than that after (58.9 ng x m(-1)). Those results may mean that the aerosols are influenced by burning of fireworks in addition to be subjected to the meteorological condition. At the same time, there is little influence of playing fireworks on the PAHs concentration, and the changes of the concentration of PAHs can be explained by the decrease of industrial and vehicular transportation pollutant during the Festival period. It can be judged by the characteristic ratio such as Fuloranthene/pyrene that the primary resource of PAHs in particles is the combustion of coal, and the combustion of gasoline is in the next place.

Distribution patterns of nitrobenzenes and polychlorinated biphenyls in water, suspended particulate matter and sediment from mid- and down-stream of the Yellow River (China).

Samples of water, suspended particulate matter (SPM) and sediment were collected from mid- and down-stream of the Yellow River. The distribution and concentration of 10 nitroaromatic compounds and polychlorinated biphenyls (PCBs) were extensively studied. The total concentration of 10 nitrobenzenes (SigmaNBs) varied from 0.269 to 9.052 microg l(-1) in water, from 2.916 to 164.4 microg kg(-1) dry weight in SPM, and from 0.954 to 14.72 microg kg(-1) dry weight in sediment. PCBs associated with the sediments, measured as the summed responses of Aroclor 1242, 1248, 1254, 1260 (in comparison to those of a standard 1:1:1:1 mixture), were found to be in the range of non-detectable to 5.98 microg kg(-1). In the samples collected, various PCB congeners showed similar distribution characteristics with congeners containing 3-5 chlorine atoms accounting for more than 96.4% of total PCB. In most of the samples, PCB concentrations occurred in the order: TetraCB > TriCB > PentaCB. Levels of SigmaNBs in the Yellow River were relatively low in comparison with values reported from other river and marine systems, and PCB levels were comparatively low. Relative to the PCBs, SigmaNBs showed significantly more difference among the various stations, presumably due to the influence of different pollution sources. No obvious correlation was observed between the pollutant concentrations and either the TOC or the grain size of the sediments.