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Ammonia （NH 3 ） is an important alkaline reactive nitrogen, which, as a precursor of fine particulate matter, raises public health issues. In this study, online NH 3 , SO 2 , NO 2 , PM 2.5 , and its water-soluble inorganic ions were detected to deduce the influence of NH 3 on aerosol liquid water content （AWC） and aerosol pH, including the formation of water-soluble secondary ions in PM 2.5 in winter in Changzhou, an ammonia-rich city in the Yangtze River Delta area in winter. The results showed that NH 4 + mainly existed in the form of NH 4 NO 3 and （NH 4 ） 2 SO 4 , and the remaining NH 4 + existed as NH 4 Cl. Owing to the NH 3 -NH 4 + buffer system, the aerosol pH values were found at 4.2 ± 0.4, which was positively correlated with the NH 3 content. The aerosol pH value variation narrowed with the increase in PM 2.5 concentration and tended to be between 4 to 5. AWC increased exponentially with the increase in humidity and SNA content, among which NH 4 NO 3 , （NH 4 ） 2 SO 4 , and NH 4 Cl contributed 58.5%, 18.4%, and 8.3%, respectively, due to their hygroscopicity. Aerosol pH, AWC, and NH 3 -NH 4 + conversion promoted the gas-to-particle conversion of SO 2 and NO 2 . In Changzhou, rich NH 3 -NH 4 + were found to maintain relatively high pH values, push up AWC, and promote the heterogeneous reaction of SO 2 , whereas NO 3 - generation was dominated by a homogeneous reaction, which was accelerated by NH 3 . According to the simulation results, relatively noticeable changes in aerosol pH and AWC could be found by the reduction of up to 30% of NH 3 .

Photochemical pollution, which is believed to be influenced by emission changes and meteorological factors, is presently quite serious in the Beijing-Tianjin-Hebei (BTH) region, China. There is a need to ascertain the effectiveness of air quality management in the region based on long-term air quality trends independent from meteorological influences. We apply Kolmogorov-Zurbenko (KZ) filtering, a technique used to separate different scales of motion in a time series, to analyze the time series of the maximum daily 8-hour running average for ozone (O 3 -8h) from 13 cities in the BTH region during 2013-2018, and also discuss trends and driving factors. Results of the KZ filtering revealed that the short-term, seasonal, and long-term components of the O 3 -8h accounted for 32.7%, 63.9%, and 3.4% of the total variance, respectively. The long-term component of the BTH region was much higher than of those reported by others for Berlin, Paris, and London, and was comparable to that of Los Angeles in the early 1990s and in the 4 years previous to our study. Although we found a lower long-term component than of those reported for Shanghai and Nanjing in the Yangtze River Delta, China, the BTH region had higher rates of increase that ranged from 2.31 to 7.12 μg·(m 3 ·a) -1 [mean 4.97 μg·(m 3 ·a) -1 ]. Based on the linear fitting results-that had not been verified by experiments or model simulations-the average increase rates could be mainly attributed to emission changes (90.4%), which may be distinguished into two parts, the decrease of particulate matter (PM) (27.3%) and the emission of O 3 precursors (63.1%). Decreases of PM 2.5 in Beijing, Langfang, Tianjin, and Hengshui were considered to be responsible for the increase at the levels of 50.8%, 32.5%, 36.7%, and 48.6%, respectively. This suggests that the rapid decrease in PM 2.5 could be the most important factor in the increasing trend of O 3 in some cities. We conclude that further decreases in the emission of O 3 precursors are required to overcome the effect of decreasing PM 2.5 causing an increase in O 3 .

Statistical analysis methods was utilized to investigate the variations of monthly average concentrations of the six basic pollutants (SO 2 , NO 2 , CO, O 3 , PM 2.5 and PM 10 ) of six national standard monitoring sites from 2013 to 2014 in urban Changzhou. The results showed that, except for O 3 , SO 2 , NO 2 , CO, PM 2.5 and PM 10 concentrations were all high in winter and low in summer. The relationship between particulate matter and wind speed showed, with increasing wind speed, the concentration of PM 2.5 reduced. However, the concentration variations of PM 10 were complicated and when wind speed increased, its concentration started to go down and then elevated. Fast-cluster analysis ( k -means) and the index of SWV & DIV were used to classify the six basic pollutants into four clusters, and then the relationship between gaseous pollutants and PM 2.5 in each cluster was emphatically discussed by statistical analysis method. Four clusters were assigned to fossil fuel combustion emissions (cluster1), O 3 and secondary aerosols (cluster2), incomplete combustion emissions and regional haze (cluster3), urban city "background" (cluster4). Incomplete combustion cluster accounted for the smallest percentage of urban Changzhou and city "background" was cluster of urban Changzhou with the largest contribution. k -means analysis results also showed that PM 2.5 had complex sources in urban Changzhou.

The effect of copper ions on the water solubility enhancement of 4,4'- dibromodiphenyl ethers (BDE-15) by a commercial humic acid (HA) has been studied using batch equilibrium technique at various pHs. The characteristics of HA-Cu complex were investigated with the aid of dynamic light scattering and Zeta potential measurements. The results showed that the interaction of BDE-15 with HA could be explained by partition according to the linear isotherms when HA were at lower level, while the non-linear isotherms were observed at higher level of HA. The capability of solubility enhancements was affected by the pH and the ratio of the concentration of copper ions and the concentration of HA. At low pH condition (pH 4.0), solubility enhancement of BDE-15 by HA was facilitated by Cu2+ at low concentration, but reduced by Cu2+ at high concentration. While the phenomenon was different at pH 6.0, and Cu2+ over all investigated concentration range promoted the capability of HA enhancing BDE-15 solubility and non-linear isotherms became more significant. The different effects of Cu2+ at pH 4.0 and 6.0 was mainly due to the dissociation of the HA functional groups as pH increased, thus affected the structure and size of HA-Cu complex.

Water solubility enhancements by two types of dissolved organic matter (DOM) extracted from a local wastewater treatment plant and by a commercial humic acid (HA) have been studied for tetrabromobisphenol A (TBBPA) using batch equilibrium technique, and the characteristics of DOM were studied with the aid of infrared and ultraviolet absorbance, elemental analysis, dialysis membranes and scanning electron microscope (SEM). The results showed that the effectiveness of DOM in enhancing solute solubility appeared to be controlled by the structure and molecular size of DOM, the ionic strength of solution and the dissociation ratio of TBBPA. Langmuir Equation could fit the isotherms of the total influent DOM and effluent DOM, and their binding coefficients (Kdoc) are 1.19 x 10(5) L x kg(-1) and 1.27 x 10(5) L x kg(-1), respectively. The interaction of TBBPA with DOM (relative molecular weight > 1000) can be explained by partition according to the linear isotherms, while the nonideal binding behavior of the total DOM was caused by DOM (relative molecular weight < 1000) which contributed about 75 % to 80% of the total water solubility enhancement effect and had higher binding coefficients to TBBPA, about 55%, than those of DOM (relative molecular weight > 1000). The capability of solubility enhancements by the influent DOM and effluent DOM was greater than that of HA in which the high molecular weight DOM controlled the effect of solubility enhancement. In addition, it was also found that the capability of solubility enhancements was affected by the ionic strength of solutions. The capability of solubility enhancements was increased when the ionic strength was low, while it was decreased at higher ionic strength due to the aggregation and flocculation of DOM.

Objective: To inquire into the diagnostic significance of cytokeratin 19(CK19) and cytokeratin 20(CK20) expression on hematogenous micrometastasis of colorectal cancer., Methods: Forty-four patients with colorectal cancer were collected as colorectal cancer groups, and another 18 patients treated with abdominal surgical operations because of benign diseases were collected as benign disease group. Blood of all the patients was harvested from their portal and peripheral veins, and CK19 and CK20 levels in the blood were determined by RT-PCR., Results: There were no positive expression of CK19 and CK20 in the portal and peripheral blood of all the patients in benign disease group. Of the colorectal cancer group, 34 patients(77.3%) appeared positive expressions of CK19 and/or CK20 in portal and peripheral blood, and there was significant difference in the expressions of CK19 and CK20 between the two groups(P<0.05). Within the colorectal cancer group, the positive expression rates of CK19 and CK20 in peripheral blood were 36.4% and 52.3%, and the rates in portal blood were 59.1% and 72.7%. The rates of portal blood were significantly higher than those of peripheral blood(P<0.05). The positive expression rate in patients at stage III( was significantly higher than that in patients at stage I( orII( (P<0.05). The postoperative metastasis and recurrence rate of colorectal cancer in patients with positive expression of CK19 and CK20 in peripheral blood was 61.5%, which was significantly higher than that(25.0%) in patients with positive expression in portal blood only(P<0.05)., Conclusions: In patients with colorectal cancer, the expressions of CK19 and CK20, which are determined by RT-PCR in blood from portal and peripheral veins, are the sensitive and specific indexes for diagnosing hematogenous micrometastasis of the cancer.

Sorption and desorption behaviors of tetrabromobisphenol A (TBBPA) on fluvo-aquic soil were investigated using batch equilibrium experiments, and the effects of pH and ionic strength on the sorption were also evaluated. The results showed that the sorption process could be divided into the rapid sorption (0-24 h) and the slow sorption (24-48 h). The rapid sorption played the main role in the sorption of TBBPA and the sorption approached equilibrium at about 48 h. The nonlinear isotherm of TBBPA on the soil was observed, and the sorption behavior could be described by Freundlich model well. The amount of TBBPA sorption decreased with the increase in solution pH within the range of pH 6.0-8.0, and did not change significantly with the increase in solution pH when pH value was greater than 8.0. The amount of TBBPA sorption increased with the increase in ionic strength. In addition, the result of sorption-desorption revealed that desorption hysteresis of TBBPA, which suggested that the fluvo-aquic soil had high affinity with TBBPA.

Aim: To comparatively study the preventive effect of gelatinizedly-modified chitosan film on peritoneal adhesions induced by four different factors in rats., Methods: Chitosan was chemically modified by gelatinization, and made into films of 60 microm in thickness, and sterilized. Two hundred Sprague-Dawley rats were randomly divided into five groups, Sham-operation group (group A), wound-induced adhesion group (group B), purified talc-induced adhesion group (group C), vascular ligation-induced adhesion group (group D), and infection-induced adhesion group (group E), respectively. In each group, the rats were treated with different adhesion-inducing methods at the cecum of vermiform processes and then were divided into control and experimental subgroups. Serous membrane surface of vermiform processes were covered with the films in the experimental subgroups, and no films were used in the control subgroups. After 2 and 4 wk of treatments, the abdominal cavities were reopened and the adhesive severity was graded blindly according to Bhatia's method. The cecum of vermiform processes were resected for hydroxyproline (OHP) measurement and pathological examination., Results: Adhesion severity and OHP level: After 2 and 4 wk of the treatments, in the experimental subgroups, the adhesions were significantly lighter and the OHP levels were significantly lower than those of the control subgroups in group B (2 wk: 0.199 +/- 0.026 vs 0.285 +/- 0.041 microg/mg pr, P < 0.001; 4 wk: 0.183 +/- 0.034 vs 0.276 +/- 0.03 microg/mg pr, P < 0.001), D (2 wk: 0.216 +/- 0.036 vs 0.274 +/- 0.040 microg/mg pr, P = 0.004; 4 wk: 0.211 +/- 0.044 vs 0.281 +/- 0.047 microg/mg pr, P = 0.003) and E (2 wk: 0.259 +/- 0.039 vs 0.371 +/- 0.040 microg/mg pr, P < 0.001; 4 wk: 0.242 +/- 0.045 vs 0.355 +/- 0.029 microg/mg pr, P < 0.001), but there were no significant differences in groups A (2 wk: 0.141 +/- 0.028 vs 0.137 +/- 0.026 microg/mg pr, P = 0.737; 4 wk: 0.132 +/- 0.031 vs 0.150 +/- 0.035 microg/mg pr, P = 0.225) and C (2 wk: 0.395 +/- 0.044 vs 0.378 +/- 0.043 microg/mg pr, P = 0.387; 4 wk: 0.370 +/- 0.032 vs 0.367 +/- 0.041 microg/mg pr, P = 0.853); Pathological changes: In group B, the main pathological changes were fibroplasias in the treated serous membrane surface and in group D, the fibroplasia was shown in the whole layer of the vermiform processes. In group E, the main pathological changes were acute and chronic suppurative inflammatory reactions. These changes were lighter in the experimental subgroups than those in the control subgroups in the three groups. In group C, the main changes were foreign body giant cell and granuloma reactions and fibroplasias in different degrees, with no apparent differences between the experimental and control subgroups., Conclusion: The gelatinizedly-modified chitosan film is effective on preventing peritoneal adhesions induced by wound, ischemia and infection, but the effect is not apparent in foreign body-induced adhesion.