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The antioxidant natural product sulforaphane (SFN) is an oil with poor aqueous and thermal stability. Recent work with SFN has sought to optimize methods of formulation for oral and topical administration. Herein we report the design of new analogs of SFN with the goal of improving stability and drug-like properties. Lead compounds were selected based on potency in a cellular screen and physicochemical properties. Among these, 12 had good aqueous solubility, permeability and long-term solid-state stability at 23 °C. Compound 12 also displayed comparable or better efficacy in cellular assays relative to SFN and had in vivo activity in a mouse cigarette smoke challenge model of acute oxidative stress.

Guiyu, China, is well-known for the crude disposal of electronic waste (EW) and severe persistent organic pollutants (POPs). Therefore, in this study, the occurrence, composition, and source of polybrominated diphenyl ethers (PBDEs), 2,2',4,4',5,5'-hexabromobiphenyl (BB153), some novel brominated flame retardants (NBFRs), Dechlorane Plus (DP) and polybrominated dibenzo-p-dioxins/dibenzofurans (PBDD/Fs) in farmland soils covering Guiyu were studied. In EW disposal area soils, PBDEs were the most abundant FRs, with concentrations of 13-1014 ng g-1. The primary PBDE sources were technical Penta- and Deca-BDE mixtures in northern and southern Guiyu, respectively. The levels of BB153 were relatively low, possibly because it has been banned in the 1970s. The concentrations of hexabromobenzene (HBB) were 0.048-3.3 ng g-1, while pentabromoethylbenzene (PBEB) was almost not detected in the soils. Two alternatives to commercial PBDEs, decabromodiphenyl ethane (DBDPE) and 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), were the primary NBFRs, with concentrations of 1.8-153 ng g-1 and 0.43-15 ng g-1, respectively. DP was another primary FR, with concentrations of 0.57-146 ng g-1. Moreover, syn-DP and anti-DP isomers were not stereoselectively decomposed during the EW disposal process and were therefore present in their original fractions in the soils. The levels of PBDD/Fs in EW disposal area soils were 2.5-17 pg TEQ g-1. 1,2,3,4,6,7,8-HpBDF and OBDF were the dominant congeners, mainly derived from processing, pyrolysis and combustion of BFRs. The regional distribution of pollutants was shown to be related to the disposal manner of EW, with their open thermal disposal tending to release more highly brominated compounds such as BDE209, DBDPE, and 1,2,3,4,6,7,8-HpBDF. Additionally, some riverbank sites were heavily polluted because of nearby point sources, downwind Simapu (SMP) town without EW disposal activity was also contaminated by these pollutants.

Cellulose nanocrystals (CNCs) are most commonly prepared by sulfuric acid hydrolysis of a purified cellulose starting material but the effects of hydrolysis conditions on CNC yield and properties are incompletely understood. In this study, we use a rotatable central composite experimental design to elucidate parameter interactions between three design factors, acid concentration (x1), hydrolysis temperature (x2), and hydrolysis time (x3), over a broad range of process conditions and determine their effect on yield and sulfate group density. Parameter ranges are 55–65 wt.% for x1, 45–65 °C for x2, and 30–180 min for x3. Regression models of the experimental yield data reveal significant two-factor interactions of x1 with each x2 and x3, whereas x2 has no significant two-factor interaction with x3. The models predict maximum yields of 66–69% at optimum process conditions of 57–58 wt.% (x1), 64–67 °C (x2), and 134–156 min (x3). At these conditions, the sulfate group density is predicted to be between 241 and 265 mmol/kg. The sulfate group density is linearly dependent on acid concentration and hydrolysis temperature and not dependent on hydrolysis time. Maximum sulfate group density can only be achieved at the expense of yield. The results presented here provide a foundation for subsequent, sequential optimization using narrower parameter ranges, allowing further optimization of the hydrolysis conditions and potentially enabling higher yield.

A one-year-long aerosol characterization study was conducted from July 2002 through July 2003, in Beijing, China. Twenty-four hour PM2.5 and PM10 filter samples were collected, and about 50 aerosol samples of each type were obtained. Organic, elemental, and total carbon, levoglucosan and other organic compounds, and inorganic ionic species were measured. The overall mean PM mass concentrations were 99 and 175 mu g/m(3) for PM2.5 and PM10, respectively. Total carbon was the main component in both PM2.5 and PM10, with overall mean concentrations of 21 and 30 mu g/m(3), respectively. Of the organic compounds measured, levoglucosan exhibited the highest levels (overall mean of 0.31 mu g/m(3) in PM2.5 and of 0.40 ng/m(3) in PM10). Sulfate was the most prominent inorganic ionic species, with overall mean levels of 15.6 and 17.0 mu g/m(3) in PM2.5 and PM10, respectively. Most components measured were predominantly present in the PM2.5 size fraction; the overall mean PM2.5/PM10 ratio was typically in the range of 0.7-0.8, but this ratio was only 0.55 for the PM mass and for Ca2+ it was as low as 0.19. In PM2.5, total carbon exhibited relatively larger concentration levels (30 mu g/m(3)) in winter than in the other seasons. K+ also exhibited a relatively high concentration level in the winter season, with 2.3 mu g/m(3) in PM2.5. The contribution from biomass burning to K+ in PM2.5 was estimated on the basis of the levoglucosan data and the minimum K+/levoglucosan ratios obtained throughout the year; it was found that the contribution was largest in autumn, with 44%.

Using Monte Carlo simulation, the geometric and matrix effects on intensity and intensity ratio measured by EPMA were investigated for both synthetic particles and biomass burning particles. Three particulate standards, KCl, K2SO4, KHSO4, were prepared and measured along with biomass burning particles. The modified CASINO program (University of Sherbrooke, Quebec, Canada) at the University of Antwerp, Belgium was used. The relative intensities obtained by the UA version of the CASINO program appear to be in line with those from experiments. The CASINO program and iterative procedures were applied to quantitatively determinate the atomic fraction of K, Cl and S in particulate standard and real samples. After correcting the geometric and matrix effects, the atomic fraction ratio of K to Cl in KCl sample was found to be 1.007±0.025, 0.996±0.013 and 1.011±0.019 for experiments with high voltages of 15, 20 and 25 keV, respectively. The same procedure was also applied to K2SO4 and KHSO4 standard particle sample. The atomic fraction ratio of K to S was 1.945±0.049 (25 keV) for K2SO4 and 1.014±0.072 (20 keV) for KHSO4. These ratios obtained are close to the theoretic values 1 or 2. Reasonable data were obtained for biomass burning particles, indicating that it is possible to perform chemical speciation.

A method was developed for the analysis of mutagenic nitroarenes in carbon black. The procedure included extraction, pre-separation column chromatography on silica gel, and determination by high-performance liquid chromatography (HPLC) using a diode-array detector. Different solvents, such as dichloromethane, benzene, toluene, and chlorobenzene were used for the extraction of carbon black. It was found that chlorobenzene yielded the highest amount of extracted material. The pre-separation, the optimization of the HPLC separation, the selection of detection wavelengths, and the calibration curve are discussed. 3-Nitro-9-fluorenone was detected in a treated carbon black, which is used for making carbon ink. The identification of peaks in the sample chromatograms was confirmed by comparing the retention time and the UV spectra with those of standards.