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To elucidate the characteristics of VOCs chemical components during heavy pollution episodes, hourly online VOCs data derived from 11 heavy pollution events in Tianjin from 2019 to 2020 were employed. The positive matrix factorization （PMF） and conditional bivariate probability function （CBPF） were employed to analyze the sources of VOCs during heavy pollution episodes. The results indicated that the average VOCs volume fraction during these episodes was recorded at 35.7×10 -9 . Furthermore, it was observed that during the winter emergency response period, there was a discernible increase in the volume fraction of VOCs when compared to that during the autumn season. Specifically, there was a notable upswing of 48% in the olefins category, whereas alkanes registered a 4% increase. Additionally, the VOCs component structure changed significantly during the heavy pollution episodes. During the orange warning period, the proportion of alkanes increased by 36%, and the proportion of acetylene decreased by 32%. During the yellow warning period, the proportion of alkanes increased by 14%, and the proportion of acetylene decreased by 5%. During the emergency response period, motor vehicle emission sources, natural gas evaporative sources, and solvent use sources were the main contributors of VOCs in environmental receptors, contributing 17.5%, 15.4%, and 15.2%, respectively. Compared with that during the period antecedent to the emergency response, the contribution of vehicle emission sources and diesel volatile sources to VOCs in environmental receptors decreased by 2.0% to 5.5% and 2.1% to 6.6%, respectively, and the contribution of solvent use sources decreased by 0.2% to 2.4% during the yellow warning period. During the orange warning period, the contribution of motor vehicle emission sources was reduced by 0.1% to 8.3%, and the contribution of solvent use sources was reduced by 0.5% to 6.2%.

The spatial distribution, accumulation features, and driving factors of O 3 pollution were analyzed using spatial autocorrelation and hotspot analysis and the STIRPAT model based on the high spatiotemporal resolution online monitoring data from 2016 to 2020 in Tianjin. The results showed that the variation characteristics of O 3 concentration in Tianjin from 2016 to 2020 had the trend of pollution occurring in advance and the scope of the pollution expanding. The distribution of O 3 pollution showed significant aggregation from June to October. High-high value clustering areas included six urban districts, Beichen District, Jinnan District, and Jinghai District. O 3 concentration formed high value hot spots in the southwest and low value cold spots in the northeast. Meteorological factors such as temperature, breeze percentage, and sunshine duration, as well as social factors such as NO x emission, VOCs emission, and motor vehicle ownership had significant effects on O 3 concentration. The regression fitting effect of the integrated drive STIRPAT model was better than that of the single meteorological factor or social factor models. In order to promote scientific and efficient prevention and control of ozone pollution during the 14 th Five-Year Plan period, meteorological conditions require attention; under the goal of "peaking carbon dioxide emissions and achieving carbon neutrality," it is necessary for Tianjin to further improve the emission performance of steel, petrochemicals, thermal power, building materials, and other industries, Additionally, clean upgrading, transformation, and green development should be guided for enterprises to reduce VOCs and NO x emissions. At same time, the increase in fuel vehicle numbers should be controlled, and new energy vehicles should be vigorously promoted to reduce vehicle emissions.

Based on the hourly O 3 concentration data of 337 prefectural-level divisions and simultaneous surface meteorological data in China, we applied empirical orthogonal function (EOF) analysis to analyze the main spatial patterns, variation trends, and main meteorological driving factors of O 3 concentration in China from March to August in 2019-2021. In this study, a KZ (Kolmogorov-Zurbenko) filter was used to decompose the time series of O 3 concentration and simultaneous meteorological factors into corresponding short-term, seasonal, and long-term components in 31 provincial capitals.Then, the stepwise regression was used to establish the relationship between O 3 and meteorological factors. Ultimately, the long-term component of O 3 concentration after "meteorological adjustment" was reconstructed. The results indicated that the first spatial patterns of O 3 concentration showed a convergent change, that is, the volatility of O 3 concentration was weakened in the high-value region of variability and enhanced in the low-value region.Before and after the meteorological adjustment, the variation trend of O 3 concentration in different cities was different to some extent. The adjusted curve was "flatter" in most cities. Among them, Fuzhou, Haikou, Changsha, Taiyuan, Harbin, and Urumqi were greatly affected by emissions. Shijiazhuang, Jinan, and Guangzhou were greatly affected by meteorological conditions. Beijing, Tianjin, Changchun, and Kunming were greatly affected by emissions and meteorological conditions.

This is a phase Ib study of anlotinib plus a programmed death-ligand 1 (PD-L1) inhibitor TQB2450 for platinum-resistant or -refractory ovarian cancer. Thirty-four patients are enrolled and receive treatment. The objective response rate (ORR) is 47.1%, and the disease control rate is 97.1%. The median duration of response (DOR) has not been reached, and 61.3% of patients have a DOR of at least 8 months. The median progression-free survival (PFS) is 7.8 months, and the median overall survival (OS) has not been reached. The PD-L1-positive group has an ORR of 25.0%, whereas the PD-L1-negative group has an ORR of 92.9%. Treatment-related grade 3 or 4 adverse events (AEs) occur in 70.6% of patients, with the most common being hypertension (29.4%) and palmar-plantar erythrodysesthesia syndrome (29.4%). Anlotinib plus TQB2450 show promising antitumor activity and manageable toxicities in patients with platinum-resistant or -refractory ovarian cancer. A phase 3 randomized controlled trial to further validate our findings is ongoing., Competing Interests: Declaration of interests Y.-F.W. is an employee of Chia Tai Tianqing Pharmaceutical Group Co., Ltd., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Fugitive dust poses an important contribution to urban air particulate matter in China. To further improve the level of dust pollution prevention and control, the emission and contribution characteristics of urban fugitive dust were summarized; the main causes of dust pollution were analyzed; and the key links, key indicators, and main measures for prevention and control were clarified, so as to further improve the concept of "accurate dust control." Among all types of fugitive dust sources, road dust and construction dust were the main emission and contribution sources, among which road dust was more prominent. Production activities, vehicle disturbances, and wind erosion were the main dust-generating links of various dust sources. Silt loading was taken as the key control index for road dust prevention and control, whereas silt loading and bare soil (or material) areas were taken as the key control index for construction and other dust sources. Around the key indicators, three main ways to control the road dust and six main measures to control the construction and other dust sources were defined. In addition, some suggestions on the necessary supporting measures for dust control were put forward, so as to provide a comprehensive and beneficial reference for the practical application of dust control in Chinese cities.

Treatment of industrial atmospheric emission sources is an important way to improve air quality, but accurate pollution control remains still an urgent challenge. Taking Xiqing District of Tianjin as an example, based on the second national pollution source census, this study carried out a quantitative evaluation of the pollutant emission performance of industrial enterprises and explored the significance, feasibility, and challenges facing emission performance evaluation. The results show that the emission performance of various industries in Xiqing District vary greatly. The pollutant emission performance level is closely related to an industry's own attributes, development scale, and management level. On the whole, the emission performance level of industries with high production process emission coefficients and a high proportion of small and medium-sized enterprises (such as furniture manufacturing, the metal products industry, ferrous metal smelting, and the rolling processing industry) is worse, while the emission performance of high-end industries represented by computer communication and other electronic equipment manufacturing and automobile manufacturing is generally better. The emission performance of different enterprises in the same industry also varies greatly. For example, the 11 enterprises with the worst performance in the metal machinery manufacturing industry only contributed 0.06% of industrial output yet their PM emission contribution reached 8.50%. The 19 worst-performing enterprises in the rubber and plastic industry contributed 4.76% of industrial output yet their VOCs emissions accounted for 43.59% of the total. At the same time, this study presents an emissions reduction plan according to the relevant technical guidelines of the Ministry of Ecology and Environment. Based on this, the cost of emissions reduction could be cut by as much as 90% when the pollutant emissions reductions of the same scale are reduced. The gap in the pollutant emissions performance of various industries and enterprises, the incongruity between economic benefits and environmental costs, and the important guiding role of emission performance evaluation for emissions reductions demonstrate the necessity of performance evaluation. Overall, this research shows that pollutant emission performance evaluation can effectively support macro-industrial structure adjustment and the environmental governance of meso-micro industrial enterprises, providing an important reference for pollution control interventions.

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 (06:00-24:00) 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 O 3 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 47% of the total alkane concentration. The average ozone formation potential (OFP) in summer was 52.1×10 -9 , and the OFP value of alkene was the highest and its contribution reached 57%. During the daytime, alkene loss accounted for 75% of the total VOC loss. The major sources of VOCs that were calculated based on the initial concentration data were the chemical industry and solvent usage (25%), automobile exhaust (22%), combustion source (19%), LPG/NG (19%), and gasoline volatilization (15%), respectively. Compared with the apportionment results based on directly monitored concentrations, the contribution of the chemical industry and solvent usage decreased by 4%, while automobile exhaust decreased by 5%. By combining the results of PMF apportionment and the OFP model to analyze the relative contributions of emission sources to ozone formation, and we found that the highest contribution source of ozone was the chemical industry and solvent usage (26%) in summer. Compared with the analysis results based on the directly monitored concentrations, the OFP values of the chemical industry and solvent usage decreased by 7%, while that of NG/LPG apparently decreased by 13%.

Aim of Study: There were many reports published on the relationship between glutathione S-transferase T1 (GSTT1) null/presence gene polymorphism and the risk of lung cancer in these years. In previous, we conducted a meta-analysis to evaluate the relationship between GSTT1 null/presence gene polymorphism and the risk of lung cancer. This study was conducted to update it., Materials and Methods: The association studies were identified from PubMed and Cochrane Library on March 1, 2016., Results: Sixty-three reports were recruited into this meta-analysis for the association of null genotype of GSTT1 with lung cancer susceptibility, consisting of 21,220 patients with lung cancer and 21,496 controls. There was a marked association between GSTT1 null genotype and lung cancer risk in overall populations and in Asians (overall populations: Odds ratio [OR] = 1.17, 95% confidence interval [95% CI]: 1.07-1.28, P = 0.006; Asians: OR = 1.41, 95% CI: 1.23-1.62, P < 0.00001). However, GSTT1 null genotype was not associated with the risk of lung cancer in Caucasians, Brazilian population, and Africans., Conclusion: GSTT1 null genotype is associated with the lung cancer risk in overall populations and in Asians.

Soil wind erosion dust is one of the primary sources of fine particulate matter (PM 2.5 ). Compared with the fugitive dust emission inventory of typical domestic provinces and cities, we found that the maximum among the contribution rates of soil wind erosion dust to the local total fugitive dust PM 2.5 emission inventory was about 4 orders of magnitude higher than the minimum. This study provided a wind erosion equation and a determination method of parameter values. The remote sensing interpretation, China soil dataset, and meteorological data of each district in Beijing were used to achieve the spatial distribution of the vegetation coverage factor ( V ), soil erodibility index ( I ), and climatic factors ( C ) in the plain area of Beijing. This study also estimated the emission factor of soil wind erosion dust and its spatial distribution. The main conclusions are as follows: ① Taking 2017 and Beijing city as an example, it was found that the climatic factor ( C ) was underestimated to different extents by domestic scholars, and PM 2.5 emission factors were overestimated or underestimated. ② V, I , and C showed apparent spatial differences and the average values of them were 0.63±0.09, 188±73, and 0.029±0.009, respectively. The maximum values of V, I , and C were 1.5, 2.1, and 4.5 times the minimum among all districts, respectively. ③ The PM 2.5 emission factor of soil wind erosion dust in Beijing showed a high spatial distribution in the northwest and southeast. The average emission factor of the city was (0.0018±0.0008) t·(hm 2 ·a) -1 , which is 0.54 times the highest emission factor (Xicheng District) and 3.12 times the lowest (Pinggu District). The area proportions of standardized emission factors with higher intensity (0.6 to 0.8] and high intensity (0.8 to 1.0] was 0.72% and 0.04%, respectively.

Background: For cervical cancer patients whose tumors display a combination of intermediate risk factors, postoperative radiation with or without adjuvant chemotherapy is suggested for them. However, who should be administered with adjuvant chemotherapy is unknown. The current study was designed to explore the clinical value of squamous cell carcinoma antigen (SCC-Ag) in guiding the use of adjuvant chemotherapy in cervical cancer patients., Methods: A total of 301 cervical cancer patients were included in the present study from March 2006 to March 2016. There were 156 patents who received adjuvant chemotherapy, while the rest of 145 patents did not receive it. The survival analysis including Overall survival (OS) and disease-free survival (DFS) was assessed by using the Kaplan-Meier method. Cox proportional hazards regression was done to detect factors in predicting the tumor prognosis., Results: In patients with high pre-treatment SCC-Ag level, those who received adjuvant chemotherapy acquired better prognosis than patients who did not receive it. Particularly, a lower rate of distant metastasis was found in the group of adjuvant chemo-radiotherapy than that in the group of adjuvant radiotherapy. As for patients with low pre-treatment SCC-Ag level, we observed no differences in both the OS and DFS between patients who were given and not given with adjuvant chemotherapy. In the multivariable analysis, adjuvant chemotherapy was significantly correlated with DFS and distant metastasis-free survival (DMFS) in patients with high SCC-Ag level., Conclusion: Preoperative SCC-Ag can be a predictive marker for the use of adjuvant chemotherapy in cervical squamous cell carcinoma with intermediate-risk factors.

Volatile organic compounds (VOCs) play an important role in the formation of ozone. The concentrations of VOCs in the Jinnan District of Tianjin were monitored by the Syntech Spectras GC955 online monitoring system, and the ozone generation potential of VOCs was calculated by the maximum incremental activity factor. The results showed that the total concentration of VOCs in the Jinnan District was (32.33±23.77) μg·m -3 , in which the mass concentration of alkane was the highest, and propylene, ethylene and toluene had the highest mass concentration. During the observation period, the ozone formation potential (OFP) of TVOC was 107.81 μg·m -3 , and the contribution of alkenes to OFP was the largest, which was 55.80%. Ethylene, isoprene, and toluene accounted for the first three places of OFP contribution rate. The backward trajectory analysis showed that TVOC and its OFPs were different under different trajectories. The estimation of VOCs/NO x volume fraction ratio showed that O 3 formation was sensitive to VOCs, which showed that atmospheric photochemical pollution has a considerable degree of regional characteristics. The concentration ratio of ethylbenzene/ m,p -xylene, and ethane/acetylene can be used to measure the progress of atmospheric chemical reaction and photochemical age in the air mass, which was proved by the aging process of VOC.

In this paper, a delayed phytoplankton-zooplankton system with the coeffcient depending on delay is investigated. Firstly, it gives the nonnegative and boundedness of solutions of the delay differential equations. Secondly, it gives the asymptotical stability properties of equilibria in the absence of time delay. Then in the presence of time delay, the existence of local Hopf bifurcation is discussed when the delay changes. In addition to that, the stability of periodic solution and bifurcation direction are also obtained through the use of central manifold theory. Furthermore, he global continuity of the local Hopf bifurcation is discussed by using the global Hopf bifurcation result of FDE. At last, some numerical simulations are presented to show the rationality of theoretical analyses.

Aim of Study: The conclusions on the association between glutathione S-transferase P1 (GSTP1) gene polymorphism and lung cancer risk are still debated. This meta-analysis was performed to update the association between GSTP1 and the risk of lung cancer., Materials and Methods: The association investigations were identified from PubMed and Cochrane Library, and eligible studies were included and synthesized using meta-analysis method., Results: Fifty reports were included into this meta-analysis for the association of GSTP1 A/G gene polymorphism and lung cancer susceptibility. The association between GSTPI G allele/GG genotype and lung cancer risk was found in this meta-analysis (G allele: odds ratio [OR] = 1.08, 95% confidence interval [CI]: 1.02-1.14, P = 0.006; GG genotype: OR = 1.09, 95% CI: 1.00-1.18, P = 0.04). However, the AA genotype was not associated with the susceptibility of lung cancer., Conclusion: GSTP1 G allele/GG genotype is associated with the lung cancer susceptibility., Competing Interests: None

To evaluate contamination by polybrominated diphenyl ethers (PBDEs) in market hens and human PBDE exposure via hen consumption in Guangzhou, hens were collected and their muscle, liver, fat, blood, yolk, and ingluvies tissues were analyzed for 13 PBDE congeners. The median highest concentration of ∑PBDEs was found in the ingluvies (5.30 ng/g lw), followed by the muscle (2.53 ng/g lw), with the lowest located in the yolk (0.09 ng/g lw). The concentrations of PBDEs in the muscle tissue of market hens in Guangzhou were at medium levels compared to others reported around the world. BDE-47, -153, -99, and -183 were the predominant congeners. The daily intake concentrations of PBDEs from hen muscle were estimated to range from 0.08 to 0.31 ng/kg/day in this study, with a Hazard Quotient (HQ) below 1.0. These results suggest that the health risk of PBDEs for the general population, through the consumption of market hens in Guangzhou, was generally low. However, the intake of PBDEs via food consumption may be one major exposure pathway for the general population of Guangzhou., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Few efforts have been made to elucidate the influence of weather conditions on the fate of semivolatile organic compounds (SOCs). Here, daily fine particulate matter (PM 2.5 ) during clear, haze, and fog episodes collected in the winter in Beijing, China was analyzed for polycyclic aromatic hydrocarbons (PAHs), brominated flame retardants (BFRs), and organophosphate flame retardants (OPFRs). The total concentrations of PAHs, OPFRs, and BFRs had medians of 45.1 ng/m 3 and 1347 and 46.7 pg/m 3 , respectively. The temporal pattern for PAH concentrations was largely dependent on coal combustion for residential heating. OPFR compositions that change during colder period were related to enhanced indoor emissions due to heating. The mean concentrations of SOCs during haze and fog days were 2-10 times higher than those during clear days. We found that BFRs with lower octanol and air partition coefficients tended to increase during haze and fog episodes, be removed from PM 2.5 during clear episodes, or both. For PAHs and OPFRs, pollutants that are more recalcitrant to degradation were prone to accumulate during haze and fog days. The potential source contribution function (PSCF) model indicated that southern and eastern cities were major source regions of SOCs at this site.

Background: It remains unknown whether blockade of c-Met signaling and epidermal growth factor receptor signaling is effective in suppressing the growth of human colorectal cancer (CRC) cells. In this study, we investigated the effects of the c-Met inhibitor PHA-665752 alone and in combination with cetuximab on the growth of human CRC cells in vitro and in mouse xenografts., Methods: Human CRC cell lines (Caco2, HCT-116, and HT-29) and mice bearing HCT-116 xenografts were treated with cetuximab in the absence or presence of PHA-665752. Cell viability and apoptosis were examined using the MTT and TUNEL assays, respectively. Vimentin was measured by immunohistochemistry as a marker for epithelial-to-mesenchymal transition. Western blotting was used to determine signaling protein expression levels., Results: The MTT assay showed that the growth of Caco2, HCT-116, and HT-29 cells was inhibited by PHA-665752 in a dose-dependent manner, but only Caco2 cell growth was suppressed by cetuximab. Combination treatment with PHA-665752 and cetuximab inhibited the proliferation of Caco2 cells and RAS mutant CRC cell lines. However, relative to the PHA-665752-alone treatment group, HT-29 cells with a BRAF mutation showed no noticeable effect. The mean tumor volume in mice treated with cetuximab in combination with PHA-665752 was significantly smaller than that in the mice treated with only cetuximab (P = 0.033) or PHA-665752 (P < 0.01). Similarly, the expression of vimentin in the mice treated with PHA-665752 in combination with cetuximab was significantly lower than that in the mice treated with cetuximab or PHA-665752 alone (P < 0.05 in each case). TUNEL assays revealed that treatment with PHA-665752 in combination with cetuximab markedly increased CRC cell apoptosis. Western blotting analysis of signaling protein expression showed that PHA- 665752 inhibited Met phosphorylation (P < 0.05). In addition, treatment with cetuximab alone or in combination with PHA-665752 effectively inhibited EGFR phosphorylation (P < 0.05)., Conclusion: Combination treatment with PHA-665752 and cetuximab suppressed in vitro and in vivo CRC cell growth more than treatment with either agent alone did., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

The objective of this study was to compare the effect of source (corn DDGS, rice bran, or soybean) or form of oil (extracted or intact) on apparent total tract digestibility (ATTD) and true total tract digestibility (TTTD) of acid-hydrolyzed ether extract (AEE) and fatty acids. The study determined and compared the ATTD or TTTD of AEE and fatty acids in extracted corn oil, rice oil, and soybean oil with intact oil in corn DDGS, full-fat rice bran, and full-fat soybean. Seventy-eight barrows (initial BW = 47.2 ± 3.9 kg; Duroc × Landrace × Yorkshire) were allotted to 1 of 13 dietary treatments in a randomized complete block design with 6 barrows in each dietary treatment. The 13 experimental diets included 1 cornstarch-soybean meal basal diet (AEE, 0.56%) and 3 diets containing 6% extracted oils (corn oil, rice oil, and soybean oil) and 9 diets supplemented with 3 levels of corn DDGS (17%, 34%, and 51%), full-fat rice bran (14%, 28%, and 42%), and full-fat soybean (12%, 24%, and 36%). These diets provided about 2%, 4%, and 6% intact oil, respectively. The barrows were housed in individual metabolism crates and were fed the assigned test diets at 4% of initial BW per day. A 5-d total collection of feces followed a 7-d diet adaptation period. The ATTD of AEE were calculated for each diet. The endogenous flow of AEE associated with each ingredient and values for TTTD were calculated using regression methods. The ATTD of AEE were greater ( < 0.05) for extracted oil than for intact oil. Compared to extracted oil, intact oil had lower ( < 0.01) ATTD of palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1), linoleic acid (C18:2), and linolenic acid (C18:3). However, a source by form interaction ( < 0.01) was observed for ATTD of C18:0, C18:2, and C18:3. The ATTD of C18:0, C18:2, and C18:3 in extracted corn and rice oil were greater compared with intact corn DDGS and rice oil ( < 0.05), while there was no significant difference for the ATTD of C18:0, C18:2, and C18:3 between extracted soybean oil and intact oil in full-fat soybean. In conclusion, lipids that are extracted have a greater digestibility compared with intact lipids, and this is especially true regarding saturated fatty acids. The ATTD of AEE in 2 forms of rice oil (intact oil and extracted oil) was less than the values in corn oil and soybean oil. The TTTD of AEE in corn DDGS and full-fat soybeans were greater than in full-fat rice bran.

Objective: MicroRNAs have emerged as key regulators in cancer cell biology. In the present study, we investigate the role and the involving mechanism of miR-370 in the progression of liver cancers., Materials and Methods: MiR-370 levels were detected by real-time PCR assay. Cell proliferation of HepG2, MHCC-97H and SMMC-7721 was determined by MTT assay. PI staining was detected by FACS analysis. Colony formation was used to test liver cancer cell growth. FoxO3a and Akt expression was determined by western blotting analysis., Results: MiR-370 level was significantly down-regulated in liver cancer cells. Functional analysis revealed that miR-370 mimics suppressed cell proliferation of liver cancer cells, while transfection with miR-370 inhibitor increased cell proliferation of liver cancer cells. Moreover, miR-370 mimics induced cell death of HepG2. Furthermore, Western blotting analysis results demonstrated that miR-370 inhibited the proliferation of liver cancer cells by activating FoxO3a., Conclusions: MiR-370 inhibited cell proliferation of liver cancer cells by PI3K/Akt signaling pathway. It worked as a tumor suppressor to suppress the progression of human liver cancers.

Light absorption properties of water-soluble organic carbon (WSOC) were investigated in the urban area of Guangzhou. The fine particulate matter (PM₂.₅) and size-segregated samples were collected in September and December of 2014 and January of 2015. The variation of absorption with wavelength of WSOC was characterized by the absorption Angström exponent (AAEabs). The AAE values of WSOC in PM₂.₅ were 3.72 ± 0.41 in autumn and 3.91 ± 0.70 in winter, which were lower than those in Beijing and north America. The mass absorption efficiency (MAE) of WSOC at 365 nm wavelength was 0.52 m² · g⁻¹ in autumn and 0.92 m² · g⁻¹ in winter, exhibiting distinct variations between autumn and winter. In winter, the MAEwsoc values exhibited a decreasing trend with increasing particle size, and all size-segregated MAE(WSOC) values in autumn were lower than those in winter, particularly for the particles < 0.95 µm, suggesting more contribution of the secondary formation to WSOC. Comparing the MAE values of elemental carbon (EC) and WSOC, it could be found that the contribution of WSOC to the light extinction of particles couldn't be ignored when the particles were mainly emitted from primary sources.

In this study, PM2.5 samples were collected at four heights (10m, 40m, 120m and 220m) at a meteorological tower in the daytime and nighttime during the heating season in Tianjin, China. The vertical variation and diurnal variability of the concentrations of PM2.5 and main chemical compositions were analyzed in clear days and heavy pollution days. Generally, mass concentrations of PM2.5 and the chemical compositions showed a decreasing trend with increasing height, while mass percentages of SO4(2-), NO3(-) and OC showed an increasing trend with increasing height. Concentrations of ion species and carbon compound in PM2.5 samples in the daytime were higher than those collected at night, which was due to intense human activities and suitable meteorological condition in the daytime. The ratios of NO3(-)/SO4(2-) and OC/EC were also considered, and we have observed that their levels on heavy pollution days were higher than those on clear days. In addition, source apportionments were identified quantitatively using the CMB-iteration model. The results indicated that contributions of secondary ion species increased with increasing height, while contributions of other pollutant sources decreased, and contributions of vehicle exhaust were relatively high on clear days., (Copyright © 2015 Elsevier B.V. All rights reserved.)

China has witnessed rapid economic growth in the past three decades, especially in coastal areas. Particulate matter (PM) pollution is becoming increasingly serious in China's cities along the western Pacific coast with the rapid development of China's society and economy. This study analyzed PM (PM10 and PM2.5) in terms of their mass and chemical composition in four coastal Chinese cities. The goal was to study the spatial variation and characteristics of PM pollution in sites under different levels of economic development and in diverse natural environments. A distinct trend for concentrations of PM and related chemical species was observed and increased from south to north in Haikou, Ningbo, Qingdao, and Tianjin. Secondary inorganic aerosols, crustal materials, and organic matter dominated the composition of both PM10 and PM2.5. Crustal materials were the most abundant species in the northern coastal areas because these areas have less vegetation cover and lower humidity than southern coastal areas. The presence of high SO4 (2-)/nitrate (NO3 (-)) concentrations indicated that the burning of coals gives significant contributions to PM10 and PM2.5. The differences observed in the characteristics of PM pollution in these coastal cities are probably caused by different levels of industrial and urban development.

Umbilical cord blood mononuclear cells (UCBMC) transplantation may improve hypoxia-induced brain injury in neonatal rats, but the mechanism is unclear. This study examines whether UCBMC promote neural stem cell (NSC) proliferation via the Sonic hedgehog (Shh) signaling pathway. The rats underwent left carotid ligation followed by hypoxic stress. UCBMC were transplanted 24h after hypoxia ischemia (HI), and immunohistochemistry, immmunoblotting, and morphology analyses were performed at different time points after transplantation. Increased numbers of NSCs were observed in the subventrical zone (SVZ) of the HI+UCBMC group, but these increases were attenuated by cyclopamine treatment. There were significant increases in Shh and Gli1 protein levels after transplantation in the HI group treated with UCBMC compared to HI rats treated with phosphate-buffered solution (PBS). Significantly more Gli1(+)DAPI(+) cells were observed in the SVZ of the HI+UCBMC group compared to the HI+PBS and N+UCBMC groups, but few Gli1(+)DAPI(+) cells were found in the SVZ of the HI+cyclopamine+UCBMC group. The HI+UCBMC group had significantly less neuronal loss in the cortex and CA1 sector of the hippocampus compared to the HI+PBS group, but more neuron loss was observed in the HI+cyclopamine+UCBMC group compared to HI+UCBMC. These results indicate that UCBMC may promote NSC proliferation and alleviate brain injury in HI neonatal rats via Shh signaling., (Copyright © 2013 Elsevier B.V. All rights reserved.)

The ambient PM(10) and background soil samples were collected and analyzed with ICP-AES in eight cities around China to investigate the levels of ten heavy metals (Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, and Pb). The mean concentrations of ten heavy metals in PM(10) of the eight cities of China followed the order of Zn > Pb > Mn > Cu > Ni > Cr > Co > V. The metals in the ambient PM(10) and soil were compared in each city to evaluate the heavy metal mass fraction from anthropogenic sources in ambient air. The CD values in these cities were all above 0.2, indicating that the ingredients spectrums of PM(10) and soil vary markedly. Most heavy metals were enriched in PM(10), except Fe and Ti. The results showed that almost all the cities suffer important heavy metal pollution from anthropogenic sources. The eight cities were also grouped according to their similarity in heavy metals of ambient PM(10) by cluster analysis to investigate the relationship between the heavy metals and the pollution sources of each city. The conclusion was that the eight cities were divided into three clusters which had similar industrial type and economy scale: the first cluster consisted of Shenzhen, Wuxi, and Guiyang; followed by Jinan and Zhengzhou as the second grouping; and the third group had Taiyuan, Urumqi, and Luoyang.

Expression profiling of microRNAs (miRNAs) in most diseases might be popular and provide the possibility for diagnostic implication, but few studies have accurately quantified the expression level of dysregulated miRNAs in acute myeloid leukemia (AML). In this study, we analyzed the peripheral blood mononuclear cells (PBMCs) from 10 AML patients (subtypes M1 to M5) and six normal controls by miRNA microarray and identified several differentially expressed miRNAs. Among them miR-29a and miR-142-3p were selectively encountered in Northern blot analysis and their significantly decreased expression in AML was further confirmed. Quantitative real-time PCR in 52 primarily diagnosed AML patients and 100 normal controls not only verified the expression properties of these 2 miRNAs, but also established that the expression level of miR-142-3p and miR-29a in PBMCs could be used as novel diagnostic markers. A better diagnostic outcome was achieved by combining miR-29a and miR-142-3p with about 90% sensitivity, 100% specificity, and an area under the ROC curve (AUC) of 0.97. Our results provide insights into the involvement of miRNAs in leukemogenesis, and offer candidates for AML diagnosis and therapeutic strategy.

Calcium homeostasis is critical to amyloid beta precursor protein (APP) processing. Na(+)/Ca(2+) exchanger (NCX) proteins play an important role in maintaining intracellular Na(+) and Ca(2+) homeostasis in the brain under physiological and pathological conditions. We sequenced a hyper-variable region in intron 2 of the Na(+)/Ca(2+) exchanger 1 gene (NCX1), and investigated whether insertion/deletion variations in this region are associated with the occurrence for Alzheimer's disease (AD). Examining 413 AD patients and 361 healthy controls, we identified 3 insertion/deletion polymorphisms. No significant differences of the allele and genotype frequencies were observed between the AD cases and the controls for any of the three polymorphisms. However, among the AD patients whose age at onset (AAO) was 65 years or older (n = 299), carriers of a 14 bp insertion showed a lower average AAO (ins/ins and ins/del vs. del/del, 72.49 ± 5.17 vs. 74.28 ± 5.79, p = 0.016). It suggested that this 14 bp insertion/deletion polymorphism might modulate AAO in late-onset AD patients.

There is evidence that increased concentrations of circulating homocysteine are associated with Alzheimer's disease (AD). Phosphatidylethanolamine N-methyltransferase (PEMT) is an important catalyst involved in the production of homocysteine. We investigated the association of a functional single nucleotide polymorphism (rs7946) in PEMT with sporadic AD risk in a Han Chinese population that included 386 AD patients and 366 controls. PEMT G523A was genotyped by either sequencing or PCR-restriction fragment length polymorphism analysis. The plasma homocysteine concentrations of 210 subjects were determined by high-performance liquid chromatography. Significant higher frequency of the A allele was detected in AD cases than in controls (A vs. G, p = 0.007, OR = 1.482, 95% CI 1.114-1.972). After adjusting for gender, age/age at onset, and APOE ε4 status, logistic analysis showed rs7946 was associated with AD in a dominant model (AA + GA vs. GG, p = 0.007, OR = 1.596, 95% CI 1.138-2.240). When stratified by APOE ε4 status or gender, the significant difference was only observed in the APOE ε4 non-carriers and in the female subjects, respectively. We did not find a relationship of this polymorphism with plasma homocysteine levels. These results suggested that PEMT G523A is associated with AD and that the A allele is an APOE ε4-independent risk factor for AD among Han Chinese women.

Background: Nucleic acid testing (NAT) is currently not a routine donor test in China. The aim of this study was to evaluate the current residual risk of hepatitis B virus (HBV) transmission and the value of ALT testing in preventing HBV infection., Study Design and Methods: From January 2008 to September 2009, a total of 5521 qualified donations by routine screening and 5034 deferred donations due to elevated ALT alone were collected from five blood centers. Samples were tested for HBV DNA by triplex individual-donation (ID)-NAT (ULTRIO assay, on the TIGRIS system, Novartis Diagnostics). HBV NAT-reactive samples were further analyzed by HBV serology, alternative NAT, and viral load and were diluted to simulate if they could be detected in a minipool-NAT., Results: There was no significant difference in the HBV NAT-yield rate between the qualified donations group (5/5521) and the deferred donations group (4/5034). Of these nine potential HBV-yield cases, one donor (11%) was a possible HBV window-period donor, one (11%) was a chronic HBV carrier, and seven (78%) had probable or confirmed occult HBV infections. Of seven potential HBV-yield cases quantified, the viral loads were less than or equal to 70.0 IU/mL. Minipool testing (minipools of 4, 8, and 16 donations) would miss 43% to 79% of the nine HBV-yield donations., Conclusions: Based on our findings in qualified donations, we estimate that the nationwide implementation of ID-NAT testing for HBV DNA in China would detect an additional 9964 viremic donations per year. ALT testing seems to have no significant value in preventing transfusion-transmitted HBV infection. ID-NAT versus simulated minipool-NAT using the ULTRIO test demonstrates the benefit to implement a more sensitive NAT strategy in regions of high HBV endemicity., (© 2011 American Association of Blood Banks.)

To understand the origin and chemical characteristics of precipitation in Hangzhou, rainwater samples were collected from June 2006 to May 2008. All samples were analyzed for pH, electrical conductivity, and major ions (NH⁴⁺, Ca²⁺, Mg²⁺, Na⁺, K⁺, SO₄²⁻, NO₃⁻, F⁻, and Cl⁻). Acidification of precipitation in Hangzhou was serious with volume-weighted mean pH value of 4.5, while frequency of acid rain was 95%. The calculated SO₄²⁻/NO₃⁻ ratio in Hangzhou precipitation was 2.87, which indicated that the precipitation of Hangzhou belonged to sulfate-based acid rain. The results of acid neutralization analysis showed that not all the acidity in the precipitation of Hangzhou was neutralized by alkaline constituents. The results of sea salt contribution analysis showed that nearly all SO₄²⁻, Ca²⁺, and Mg²⁺ and 33.7% of K⁺ were of non-sea origins, while all Na⁺ and Cl⁻ and 66.3% of K⁺ originated from sea sources. The principal component analysis which was used to analyze the sources of various ions indicated that chemical compositions of precipitation in Hangzhou mainly came from terrestrial sources, factory emissions, fuel wood burning, and marine sources.

The samples of total suspended particle (TSP) from sources and TSP in the ambient atmosphere were collected in 2006 at Tianjin, People's Republic of China and analyzed for 16 chemical elements, two water-soluble ions, total carbon, and organic carbon. On the basis of the chemical mass balance (CMB) model, the contributions of different TSP sources to the ambient TSP were identified. The results showed that resuspended dust has the biggest contributions to the concentration of ambient TSP. The buffering capacity of each TSP source was also determined by an analytical chemistry method, and the result showed that the constructive dust (the dust emitted from construction work) had the strongest buffering capacity among the measured sources, whereas the coal combustion dust had the weakest buffering capacity. A calculation formula of the source of buffering capacity of ambient TSP was developed based on the result of TSP source apportionment and the identification of the buffering capacity of each TSP source in this study. The results of the source apportionment of the buffering capacity of ambient TSP indicated that open sources (including soil dust, resuspended dust, and constructive dust) were the dominant sources of the buffering capacity of the ambient TSP. Acid rain pollution in cities in Northern China might become serious with a decrease of open source pollution without reducing acidic sources. More efforts must be made to evaluate this potential risk, and countermeasures should be proposed as early as possible.

The stable carbon isotope compositions of 2-methyltetrols, biomarker compounds for secondary organic aerosols formed from isoprene in the atmosphere, have been determined by gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS). In this work, isoprene with various delta(13)C values was used to produce 2-methyltetrols via an oxidation reaction with hydrogen peroxide in sulfuric acid under direct sunlight. The target compounds with different stable carbon isotope compositions were then derivatized by methylboronic acid with a known delta(13)C value and measured by GC/C/IRMS. With delta(13)C values of 2-methyltetrols and methylboronic acid predetermined, isotopic fractionation is evaluated for the derivatization process. Through reduplicate delta(13)C measurements, the carbon isotope analysis achieved excellent reproducibility and high accuracy with an average error of <0.3 per thousand. The differences between the predicted and measured delta(13)C values range from -0.10 to 0.29 per thousand, indicating that the derivatization process does not introduce isotopic fractionation. The delta(13)C values of 2-methyltetrols could be calculated on the basis of the stoichiometric mass balance equation among 2-methyltetrols, methylboronic acid, and methylboronate derivatives. Preliminary tests of 2-methyltetrols in PM(2.5) aerosols at two forested sites were conducted and revealed significant differences in their isotope compositions, implying possible application of the method in helping us understand the primary emission, photochemical reaction, or removal processes of isoprene in the atmosphere.

Several lines of evidence indicate that fibroblast growth factor 1 (FGF1) confers neuroprotection against excitotocity and contributes to the selective vulnerability of neurons in entorhinal cortex in Alzheimer's disease (AD). Especially, FGF1 is related to Apolipoprotein E (ApoE) expression in reactive astrocytes. Therefore, FGF1 is a promising candidate gene for AD. Two studies reported the association of a polymorphism that is located 1385bp upstream from the initial code of FGF1 gene (FGF1 -1385 C>T) polymorphism with AD. To determine whether this polymorphism could affect AD development, we investigated the association between this polymorphism and AD risk in 372 sporadic AD patients and 349 controls in a Chinese Han population. No significant difference of allele and genotype distributions between the AD cases and the controls was observed in the total samples (for the alleles, chi(2)=0.126; p=0.722; for the genotypes, chi(2)=0.089; p=0.765), neither when the samples were stratified by ApoE epsilon4-carrying status, age/age at onset and gender. Our data suggested no association between the FGF1 -1385 C>T polymorphism and AD risk in Chinese Han population., (Copyright 2010 Elsevier B.V. All rights reserved.)

Folate deficiency and elevated plasma homocysteine play important roles in pathogenesis of Alzheimer's disease (AD). The aim of this study was to test the association of folate metabolism-related genes, cystathionine beta-synthase gene (CbetaS) and 5, 10-methylenetetrahydrofolate dehydrogenase gene (MTHFD1), with sporadic AD. The CbetaS 844ins68 polymorphism was determined by PCR and the MTHFD1 G1958A single nucleotide polymorphism (rs2236225) by PCR-RFLP. No significant difference of allele and genotype contributions of the CbetaS polymorphism between AD cases and controls was detected, before and after stratification by APOE epsilon4-carrying status, age/age at onset and genders. No significant difference of allele and genotype contributions of the MTHFD1 polymorphism between AD cases and controls was detected in total samples. When stratified by age/at onset age, we found that A allele and AA genotype frequencies in cases were higher than in controls and the differences were close to significant [A vs. G, P = 0.032, Odds ratio (OR) 1.642, 95% CI 1.040-2.591; AA + GA vs. GG, P = 0.068, OR 1.665, 95% CI 0.961-2.885; AA vs. GG, P = 0.059, OR 3.458, 95% CI 0.894-13.369] in <65 years groups, which suggested that the MTHFD1 G1958A A allele might be a weak risk factor for early onset AD although it needs further confirmation.

We examined polymorphisms in reduced folate carrier gene (RFC1) and methylenetetrahydrofolate reductase gene (MTHFR) for association with sporadic AD (SAD) in Chinese population. Significant associations of RFC1 A80G G allele and GG genotype with SAD (p=0.008, OR=1.312, 95%CI=1.072-1.605, and p=0.042, OR=1.383, 95%CI=1.012-1.890) were found. Further stratification of total samples by APOE epsilon4 carrier status, age/age at onset and gender revealed that RFC1 A80G G allele was an APOE epsilon4-independent risk factor for late-onset AD, and it might increase the risk of AD in females. No significant associations of MTHFR C677T allele and genotype with AD were observed in total samples, but significant associations of T allele and TT genotype with AD (p=0.031, OR=1.586, 95%CI=1.042-2.414, and p=0.028, OR=2.250, 95%CI=1.074-4.712) were identified in APOE epsilon4 carrier subgroup, suggesting that MTHFR 677 T allele and APOE epsilon4 allele may synergistically act to increase AD risk. No significant effect of RFC1 G80A and MTHFR C677T polymorphisms on plasma folate and homocysteine levels was detected.

The vapor-phase and particulate-phase samples were collected from the E-waste dismantling region (E) and a reference region (S), which is located in the upwind direction of the E and where the costume industry is developed. The aim was to acquire information about the concentrations, gas/particle partitioning and distribution of polybrominated diphenyt ethers (PBDEs). 11 congeners PBDEs were detected with GC-NCI-MS. The results showed that E-waste dismantling has resulted in serious pollution and the PBDE concentrations (from tri-to deca-BDE) ranged from 51.1 pg x m(-3) to 2685 pg x m(-3) (mean:830 pg x m(-3)), while the PBDE concentrations (from tri-to deca-BDE) in S were in the range of 1.00 pg x m(-3) to 98.9 pg x m(-3) (mean: 28.7 pg x m(-3)). The gas/particle partitioning of PBDEs exhibited a strong dependence on bromine number. Low-brominated PBDEs tend to have a higher concentration in the gas-phase while highly brominated PBDEs are mostly associated with the particulate. The mass distribution of PBDEs in E (including vapor-phase and particulate-phase) was dominated by penta-BDE, accounting for 54.3% of the total PBDEs, followed by deca-BDE, accounting for 23.8%. This pollution characters validated that the E-waste did not only come from Asia, but also from North America and Europe.

Homocysteine has been identified to be associated with Alzheimer disease (AD) and methionine synthase (MS) is one of the enzymes involved in homocysteine metabolism. Confused data were reported on the association between the MS 2756 A>G polymorphism and AD. To determine if this polymorphism could affect the occurrence of AD, we investigated the association between the MS 2756 A>G polymorphism and AD risk in 353 sporadic AD patients and 346 controls in a Chinese Han population. No significant differences of allele and genotype distributions between the AD cases and the controls were observed in the total samples, neither when the samples were stratified by age/age at onset and gender. When the samples were stratified by APOE epsilon4 status, a trend of A allele and AA genotype over-representation in the AD patients in comparison with the controls was observed, but it was not statistically significant (for the alleles, A versus G OR=1.549, 95% CI 0.920-2.609, p=0.098; for the genotypes, AA versus AG+GG OR=1.485, 95% CI 0.861-2.560, p=0.153). Similar trend was observed in the APOE epsilon4 non-carrier samples of the >or=65 year subgroups and it was not statistically significant too (for the alleles, A versus G OR=1.682, 95% CI 0.901-3.140, p=0.099, for the genotypes, AA versus AG+GG OR=1.690, 95% CI 0.884-3.232, p=0.110). Our data did not reveal significant association between the MS 2756 A>G polymorphism and AD development. However, a weak effect of the A allele on developing AD could not be completely excluded.

Several lines of evidence support a role of oxidative stress in the pathology of Alzheimer's disease (AD). NAD(P)H:quinone oxidoreductase 1 (NQO1) catalyzes the two-electron reduction of quinones, preventing their participation in redox cycling and subsequent generation of reactive oxygen species. We examined association between the NQO1 C609T gene polymorphism and sporadic AD in a Chinese population comprising 311 AD patients and 330 controls. Our results showed a higher T-allele frequency in the AD cases compared with the controls. The difference was close to but did not reach statistically significant level [p = 0.059; odds ratio (OR) T versus C = 1.236; 95% confidence interval (95% CI), 0.992-1.540]. A significantly low C/C genotype frequency in the AD cases compared with the controls was detected (p = 0.025; OR C/C versus C/T + T/T = 0.674; 95% CI, 1.049-2.098) and APOE epsilon4 status analysis revealed significant difference in the APOE epsilon4 non-carriers (p = 0.036; OR = 0.633; 95% CI, 1.027-2.427). In the > or =65 years samples, significantly low C/C frequency in the AD cases in comparison with the controls was observed in the APOE epsilon4 non-carriers (p = 0.045; OR = 0.595; 95% CI, 1.010-2.794). These results indicated that the C/C genotype had a possible protective effect against AD development, and the T allele might be a weak risk factor for late onset AD.

Air samples of total suspended particles (TSP, particles less than 30-60 microm), and particles with aerodynamic diameter smaller than 2.5 microm (PM(2.5)) were collected simultaneously at Guiyu (an electronic waste recycling site), three urban sites in Hong Kong and two urban sites in Guangzhou, South China from 16 August to 17 September 2004. Twenty-two PBDE congeners (BDE-3, -7, -15, -17, -28, -49, -71, -47, -66, -77, -100, -119, -99, -85, -126, -154, -153, -138, -156, -184, -183, -191) in TSP and PM(2.5) were measured. The results showed that the overall average concentrations of TSP and PM(2.5) collected at Guiyu were 124 and 62.1 microg m(-3), respectively. The monthly concentrations of the sum of 22 BDE congeners contained in TSP and PM(2.5) at Guiyu were 21.5 and 16.6 ng m(-3), with 74.5 and 84.3%, contributed by nine congeners (BDE-28, -47, -66, -100, -99, -154, -153, -183 and -191 respectively). This pattern was similar to Tsuen Wan site of Hong Kong. Two urban sites of Guangzhou had the same congener pattern, but were different from Yuen Long and Hok Tsui sites of Hong Kong. The results also showed that the amount of mono to penta brominated congeners, which are more toxic, accounted for 79.4-95.6% of Sigma(22)PBDEs from all sites. All congeners tested in Guiyu were up to 58-691 times higher than the other urban sites and more than 100 times higher than other studies reported elsewhere. The higher concentration in the air was due to heating or opening burning of electronic waste since PBDEs are formed when plastics containing brominated flame retardants are heated.

PM(2.5) was collected at Shanghai urban and suburban sites during spring and autumn. PIXE (Proton Induced X-ray Emission) was used to investigate mass concentration of 15 elements (S, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Br, Sr, Pb) in Shanghai PM(2.5). The total mass concentration of the 15 chemical elements was higher in spring (5 038.6 ng x m(-3)) than in summer (3 810.6 ng x m(-3)). In spring, mass concentrations of these elements in urban and suburban samples were in the same level. In summer, concentration of the elements in urban samples were lower than in suburban samples, however, the elements which were originated from anthropogenic resources were in higher level in urban samples. The results of FESEM showed that Shanghai PM(2.5) was consisted of soot aggregates, coal fly ashes, minerals, bio-particles and unidentified particles. The result of Plasmid DNA assay demonstrated bioreactivity of urban PM(2.5) was more reactive than that of suburban PM(2.5), this phenomenon probably was explained by higher mass level of heavy metals and more proportion of soot aggregates in urban PM(2.5).

A method of compound-specific stable carbon isotopic analysis for the research about the sources of atmospheric formaldehyde was preliminary studied using gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS) via 2, 4-dinitrophenylhydrazine (DNPH) derivatization. In order to evaluate the reproducibility, the accuracy and the carbon isotope effects of the method, formaldehyde with different delta 13C values were used to simulate the sampling procedure. The results show that the maximal analytical deviation for all formaldehyde 2, 4-dinitrophenylhydrazone is 0.3 per thousand and the average deviations between the determined and theoretical delta 13C values of them are 0.24 per thousand +/- 0.14per thousand (ranged from 0.03 per thousand to 0.35 per thousand), less than 0.5 per thousand the technical specifications of the GC/C/IRMS system. These mean that no carbon isotopic fractionation occurred during the procedure. The study for the indoor and outdoor atmospheric formaldehyde in the restaurant show that the stable carbon isotopic compositions are significant different for different sources of formaldehyde. The present method could provide valuable information about the sources of atmospheric formaldehyde.

Mediated by copper acetate, an efficient approach to the C-N bond formation via direct aminolysis of dithioacetals 2 and 5 with ammonia, primary or secondary amines are developed under mild conditions. Enaminones 3 and 6 were thus obtained in high to excellent yields with high chemoselectivity. This type of aminolysis reaction presents a new synthetic application of the dithioacetal functionality. [reaction: see text]

Basing on the fragment (CO434610) cloned from cDNA amplified fragment length polymorphism (cDNA-AFLP), a 1191-bp cDNA sequence of CsEXP10 with a complete 3' end was obtained via rapid amplification of cDNA ends (RACE) and getting spliced with an EST (AF319471) of the same gene (Fig.2). Southern blotting analysis showed that CsEXP10 was a single copy gene in cucumber (Fig.5). The transcripts of CsEXP10 were detected by RT-PCR only in young fruit 3 d after pollination, but not in root, stem, and leaf (Fig.4A). At different developmental stages of fruit growth, Northern blotting demonstrated that CsEXP10 gene was expressed strongly in fruit 3 d and 10 d after pollination, especially the latter, but undetectable in ovaries of 2-3 cm in length and without pollination on the day flowering, and in fruits 26 d after pollination (Fig.4B). It is suggested that CsEXP10 might be highly correlated with the expansive growth of cucumber fruit.

Seasonal aerosol samples have been collected by Andersen Hi-Vol pumping system equipped with a five stage cascade impactor and a backup filter (size range: 10-7.2 microm, 7.2-3.0 microm, 3.0-1.5 microm, 1.5-0.95 microm, 0.95-0.49 microm,

Size distribution of aerosol samples collected from two urban locations (Liwan and Wushan) and a suburban location (Xinken) in Guangzhou (South China) in autumn using Micro-Orifice Uniform Deposit Impactor (MOUDI) were analyzed for 13 polycyclic aromatic hydrocarbons (PAHs) by gas chromatography with mass selective detection (GC-MS). Bimodal distribution was found for 3- and 4-ring PAHs and unimodal for 5-, 6- and 7-ring PAHs. Different PAH size distribution models were found for urban and suburban. PAHs associated with larger particles in suburban than in urban, and different aging processes of aerosols can account for it. Adsorption behavior may be the main mechanism controlled the size distribution of PAHs in urban, and adsorption, absorption and multilayer adsorption may all play a part in suburban. For the diagnostic ratios of PAHs with the same molecular weight, large differences were found between the range of 1-2.5 microm and 0.1-0.56 microm. The concentrations of 13 PAHs were 39 ng/m3 in Xinken, 71-94 ng/m3 in Wushan and 32-154 ng/m3 in Liwan, and 5-7 ring PAHs were the most abundant.

A novel method has been developed for the compound-specific carbon isotope analysis of atmospheric formaldehyde using gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS). The method allows the determination of the delta13C value for atmospheric formaldehyde at nanogram levels with higher precision and lower detection limit. In the present work, atmospheric formaldehyde was collected using NaHSO3-coated Sep-Pak silica gel cartridges, washed out by water, then derivatized by cysteamine of known delta13C value, and the delta13C value of its derivative (thiazolidine) determined by GC/C/IRMS. Finally, the delta13C value of atmospheric formaldehyde could be calculated by a simple mass balance equation between formaldehyde, cysteamine, and thiazolidine. Using three formaldehydes with different delta13C values, calibration experiments were carried out over large ranges of formaldehyde concentrations. The carbon isotope analysis method achieved excellent reproducibility and high accuracy. There was no carbon isotopic fractionation throughout the derivatization processes. The differences in the carbon isotopic compositions of thiazolidine between the measured and predicted values were always <0.5 per thousand, within the specifications of the GC/C/IRMS system. The present method was also compared with the previous 2,4-dinitrophenylhydrazine derivatization method, and this method could be performed with lower analytical error and detection limit. Using this method, four 6-h ambient atmospheric formaldehyde samples were consecutively collected from 8 to 9 March 2005. The results showed that the delta13C values of atmospheric formaldehyde were different during the daytime and nighttime. This method proved suitable for the routine operation and may provide additional insight on sources and sinks of atmospheric formaldehyde.

Air samples were collected in June of 2004 from four sites in the city of Guangzhou, a typical urban center in South China, to determine the levels, compositional profiles, and gas-particle distribution of 11 polybrominated diphenyl ether (PBDE) congeners (BDE-28, -47, -66, -100, -99, -85, -154, -153, -138, -183, and -209). The arithmetic mean atmospheric concentrations of sigmaPBDEs (sum of all target PBDE congeners except for BDE-209) in samples from the urban and city background sites were comparable to or slightly higher than those from other places around the world. The arithmetic mean atmospheric concentrations of BDE-209, however, were higherthan those in North America and Europe, and similar to the values from Japan. Congener compositions were dominated by BDE-209 in all (>70%) but an industrial site, with an average abundance of 48% for BDE-209. The PBDE patterns were generally similar to that in the technical penta-BDE mixture, Bromkal 70-5DE. Partitioning of PBDEs between the gas and particle phases (Kp) was well correlated with the subcooled liquid vapor pressure (PLO) for all of the samples, but the relationship differed between samples from different sites. The measured fractions of PBDEs in the particulate phase were compared to the predictions from the Junge-Pankow adsorption and KOA-based absorption models. The results indicated that the KOA-based model worked better than the Junge-Pankow model that tended to overestimate the particulate fractions for most PBDE congeners.

PC12 cell line, a clonal cell line derived from a pheochromocytoma of rat adrenal medulla, was used as a model of dopaminergic neuron in vitro to study the effect of alpha-lipoic acid on the 6-OHDA induced apoptosis. The results from MTT method show that 6-OHDA decreased the cell survival rate obviously. Through TUNEL (TdT-mediated dUTP-biotion nick end labeling) and Flow cytometer (FCM) detection, we found that 6-OHDA triggered cell apoptosis and induced necrosis. It was confirmed by the different percentage of cell survival rate and apoptosis concluded from FCM and MTT. alpha-lipoic acid was used as antioxidant to protect the cell from 6-OHDA's injury. The result indicateed that alpha-lipoic acid can partly prevent apoptosis induced by 6-OHDA but fail to prevent necrosis since it can decrease the apoptotic cell from 20.09% to 3.09%, just as increased cell survival rate from 56.8% to 72.6% but can not reach the normal level showed by MTT assay. Biochemical approach showed the cell's antioxidant ability especial for SOD activity and GSH content increased after the treatment of alpha-lipoic acid. The data suggest that alpha-lipoic acid may protect PC12 cells from apoptosis induced by 6-OHDA through the antioxidant path.

A simple, sensitive method for determining polychlorinated biphenyl (PCB) congeners in industrial product 2,3,5,6-tetrachloro-1,4-benzoquinone with GC/ECD detection has been developed. The method based on liquid-liquid extraction from tetrachlorinated quinone dissolved in N,N-dimethylformamide was found to be efficient for the determination of the levels of the investigated pollutants. A series of extraction and purification steps were designed for the sample pretreatment. The congener specific averages of recoveries were 82-96% for Aroclor 1242 and 1254 at a total spiking level of ca. 0.4 mug g(-1) sample. The reproducibilities of replicate determinations of different congeners were typically 5-19% except one with the average 13% R.S.D. (n=3). This method was applied to evaluate the background levels of PCBs in tetrachloro-1,4-benzoquinone, of which the corresponding PCB levels varied from 0.014 to 1.5 mug g(-1).