[Design, synthesis and anti-proliferative activity of novel coumarin derivatives linking Schiff base and aryl nitrogen mustard].

To explore novel coumarin derivatives with more potent anti-proliferative activity, a series of novel compounds were designed and synthesized by linking Schiff base and N, N-bis (2-chloroethyl) amine pharmacophore of nitrogen mustards to the coumarin's framework. Their structures were confirmed by 1H NMR, MS and element analysis techniques. In vitro anti-proliferative activities were evaluated against HepG2, DU145 and MCF7 cell lines by the standard MTT assay. The results showed that some of the target compounds exhibited strong anti-proliferative activities against selected tumor cells, and compounds 7c, 7f, 7g, 7h and 7q were better than or equal to the activities of positive control, they deserved further development.

Liquid properties of dimethyl ether from molecular dynamics simulations using ab initio force fields.

We have used molecular dynamic simulations to study the structural and dynamical properties of liquid dimethyl ether (DME) with a newly constructed ab initio force field in this article. The ab initio potential energy data were calculated at the second order Møller-Plesset (MP2) perturbation theory with Dunning's correlation consistent basis sets (up to aug-cc-pVQZ). We considered 17 configurations of the DME dime for the orientation sampling. The calculated MP2 potential data were used to construct a 3-site united atom force field model. The simulation results are compared with those using the empirical force field of Jorgensen and Ibrahim (Jorgensen and Ibrahim, J Am Chem Soc 1981, 103, 3976) and with available experimental measurements. We obtain quantitative agreements for the atom-wise radial distribution functions, the self-diffusion coefficients, and the shear viscosities over a wide range of experimental conditions. This force field thus provides a suitable starting point to predict liquid properties of DME from first principles intermolecular interactions with no empirical data input a priori.

[Synthesis and activities of 4-(2-acetoxybenzoylamino) butyramide heterocyclic compounds].

It has been demonstrated by our previous research that 4-(2-acetoxybenzoylamino) butyramide derivatives exhibited good antiepileptic activities. In this paper, to explore the SAR and improve the antiepileptic activities of these derivatives, a series of novel 4-(2-acetoxybenzoylamino) butyramide heterocyclic compounds (5a-5n) were synthesized and biologically evaluated. Their structures were confirmed by 1H MNR, ESI-MS and elemental analysis. Pharmacological test in vivo showed that target compounds (5f, 5i-5n) displayed strong antiepileptic activities on 4-AP induced epilepsy in mice with ED50 values ranging from 0.3137 to 0.3604 mmol x kg(-1).

[Design, synthesis and activities of 4-(2-acetoxybenzoylamino) butyramide derivatives].

To explore new agents of gamma-aminobutyric acid (GABA) derivatives with more potent antiepileptic activity, a series of 4-(2-acetoxybenzoylamino) butyramide derivatives were designed and synthesized. All of the novel compounds (5a-51) were synthesized from GABA as starting material, and their structures were confirmed with IR, 1H NMR, EI-MS and elemental analysis. Preliminary pharmacological test in vitro showed that all target compounds displayed strong antiepileptic activities and were worth for further study. The structure-activity relationship of 4-(2-acetoxybenzoylamino) butyramide derivatives was also discussed preliminarily.

[Characteristics and Source Apportionment of Carbon Components in Road Dust PM2.5 and PM10 During Spring in Tianjin Derived by Using the Quadrat Sampling Method].

In order to study the characteristics and sources of carbon fractions in PM2.5 and PM10 of road dust in Tianjin, samples of road dust were collected by the quadrat sampling method in April 2015 in Tianjin, and samples were re-suspended on filters by using a NK-ZXF sampler. A Thermal Optical Carbon Analyzer (IMPROVE-TOR) was employed to measure the concentrations of organic carbon (OC) and elemental carbon (EC), and the pollution characteristics and sources were investigated by non-parametric tests and OC/EC ratio, correlation, and cluster analyses. The results showed that ω(total carbon, TC) in PM2.5 of road dust amounted to 4.89% (secondary road) -18.83% (expressway), ω(OC) amounted to 3.57% (secondary road) -15.39% (expressway), and ω(EC) amounted to 1.32% (secondary road) -3.44% (expressway); meanwhile, ω(TC) in PM10 of road dust was 8.14% (secondary road) -19.71% (expressway), ω(OC) was 5.91% (secondary road) -16.28% (expressway), and ω(EC) was 1.96% (main road) -3.43% (expressway). The mass fraction of each carbon component for the expressway was relatively high, and that for the secondary trunk road was relatively low, which may have been due to the large traffic volume on the expressway and corresponding large amounts of exhaust emissions from motor vehicles, whereas there were fewer vehicles on the secondary trunk road. Additionally, ω(OC) was significantly larger than ω(EC) for all types of roads, and ω(EC) did not vary much among the different road types. The non-parametric tests of two related samples showed that there was no significant difference in the mass fraction of each carbon component between PM2.5 and PM10. The correlation analysis showed that the sources of OC and EC in road dust were roughly the same. The OC/EC ratio analysis and cluster analysis showed that the main sources of the carbon components in the dust of roads in Tianjin in spring were coal combustion, motor vehicle exhaust, and biomass burning.

[Characteristics of Elements in PM2.5 and PM10 in Road Dust Fall During Spring in Tianjin].

To explore the element pollution characteristics and sources of road dust fall, road dust fall samples were collected during spring in Tianjin and suspended to obtain PM2.5 and PM10, 16 elements were analyzed, and then their characteristics, sources, and similarities were studied by nonparametric tests, the coefficient of divergence, and enrichment factor. The results showed that the mass fraction (1%-20%) in sequential order of the elements in PM2.5 and PM10 in Tianjin road dust fall were Si > Al > Ca > Fe > Mg > K > Na. The coefficient of divergence of elements in PM10 and PM2.5 was 0.06, indicating that the elements profiles of PM10 might be similar to PM2.5. The elements of Cd and Cr in PM10 and PM2.5 were at a high level of enrichment degree, and Zn, Cu, Pb, and As showed significant enrichment. The main sources of the elements in PM10 and PM2.5 road dust fall in Tianjin were soil dust, construction dust, traffic dust (motor vehicle exhaust, tire wear, and brake wear), and coal combustion.

[Characteristics and Sources of Carbon Components in PM2.5 During Autumn and Winter in Panjin City].

In order to study the pollution characteristics and sources of carbon in Panjin City during autumn and winter, PM2.5 samples were collected at three monitoring points in October 2016 and January 2017. Pollution characteristics and sources of carbon components in PM2.5 were analyzed by the OC/EC ratio method, EC tracer method, and principal component analysis method. The results showed that the PM2.5 concentration exceeded the ambient air quality standard (GB 3095-2012) and that the average concentrations of OC and EC were 10.02 µg·m-3 and 3.91 µg·m-3 in autumn, respectively, and 16.04 µg·m-3 and 5.62 µg·m-3 in winter. According to the OC/EC ratio method, the OC/EC ratios were more than 2.0 during the sampling periods, indicating that there was secondary pollution in autumn and winter. Spearman correlation analysis and linear fitting indicated that the OC and EC sources were complex in development zones and that secondary school and cultural park areas may have similar sources during autumn and winter. SOC was quantitatively estimated by the EC tracer method, with concentrations of 7.21 µg·m-3 and 23.07 µg·m-3 in autumn and winter, respectively. The absolute and relative errors of SOC uncertainty were 0.98 µg·m-3 and 14.00% in autumn, respectively, and 1.87 µg·m-3 and 8.21% in winter. Based on the method of principal component analysis, the carbon components in autumn and winter were mainly derived from coal combustion, biomass burning, and vehicle exhaust.

[Characteristics and Source Apportionment of Water-soluble Inorganic Ions in Road Dust PM2.5 During Spring in Tianjin Using the Quadrat Sampling Method].

In order to collect comprehensive information regarding the characteristics and sources of the water-soluble inorganic ions in road dust (RD) PM2.5 in Tianjin, samples of road dust were collected in April 2015 in Tianjin, and then re-suspended on filters using a NK-ZXF sampler. The concentrations of the major water-soluble inorganic ions were analyzed by ion chromatography. A correlation analysis, ratio method, and principal component analysis were used to analyze the sources of RD PM2.5. The results showed that the total water-soluble inorganic ion concentration in Tianjin accounted for 6.13%±2.32%, varying with different road types. Na+, K+, Mg2+, and Ca2+ showed high homology. NO3-/SO42- revealed that the main source of PM2.5 was mostly attributed to fixed sources. The principal component analysis showed that the main sources of RD PM2.5 in Tianjin were coal combustion, mobile sources, biomass burning, and construction dust.

[Characteristics and Source Apportionment of Water-soluble Ions in PM2.5 During Winter in Panjin].

In order to study the characteristics and source of water-soluble ions in PM2.5 in Panjin, PM2.5 samples were collected at three sites in January of 2017, and the levels of eight ions (Na+, Mg2+, Ca2+, K+, NH4+, SO42-, Cl-, and NO3-) were determined by ICS-900 ion chromatograph. The characteristics of PM2.5, the water-soluble ion concentration, SOR and NOR calculation, and ion balance calculation were investigated, and a principal component analysis was conducted. The results showed that the concentration of PM2.5 and water-soluble ions followed a descending sequence of park > development zone > the second middle school. SO42-, NO3-, and NH4+ were the major components of the water-soluble ions at the three sampling sites. SOR and NOR values were all higher than 0.10, indicating that SO42- and NO3- were mainly converted from SO2 and NOx. The ion balance calculation demonstrated that the cationic and anion equivalents in Panjin had great correlation in winter. Further study showed that the atmosphere in the development zone presented as neutral and that in the cultural park and the second middle school presented as partially alkaline. The principal component analysis further indicated that the water-soluble ions were mainly derived from fuel combustion, biomass burning, secondary particles, and re-suspended dust in winter.

[Characteristics and Source Apportionment of Water-soluble Inorganic Ions in Road Dust PM2.5 in Selected Cities in Liaoning Province].

In order to collect comprehensive information on the characteristics and sources of water-soluble inorganic ions in road dust (RD) PM2.5 in Liaoning Province, samples of road dust were collected in 2014 and 2016 in Anshan and Panjin and then re-suspended on filters using an NK-ZXF sampler. The concentrations of the major water-soluble inorganic ions were analyzed by ion chromatography. A correlation analysis, ratios, and a principal component analysis were used to analyze the sources of RD. The results showed that the total water-soluble inorganic ions in Panjin and Anshan accounted for 5.83%±3.34% and 5.84%±1.15% in RD PM2.5, respectively. NH4+, SO42-, and NO3- in RD PM2.5 coexisted in the forms of (NH4)2SO4, and NH4NO3 in Panjin, and NH4HSO4 and NH4NO3 in Anshan. The average values of NO3-/SO42- were 0.52±0.55 and 0.46±0.13 for Panjin and Anshan, respectively, indicating that the effects of stationary sources (e.g., coal combustion) on PM2.5 were more significant. The main sources of RD PM2.5 in Panjin were biomass burning, sea salt particles, construction dust, and mobile sources, while the main sources of RD PM2.5 in Anshan were coal combustion, biomass burning, sea salt particles, and steel smelting dust.