[Immobilization Mechanism of Four Types of Amendments on Cu and Cd in Polluted Paddy Soil].

Cu and Cd are common pollutants in the soil surrounding copper smelting enterprises. The regional characteristics of southern China results in a high risk of Cu and Cd reactivation in soil after immobilization with soil amendment. To clarify the degree of risk of secondary activation of Cu and Cd, four types of amendments, namely limestone (LS), maifanite (MF), biochar (BC), and iron modified biochar (Fe-BC), were used to study Cu and Cd fraction distribution in soil and soil colloids and the type and fractional changes of in-situ iron oxides. The results showed that the soil amendments were ranked by their immobilizing effect on soil Cu and Cd in the order LS, MF, Fe-BC, and BC; the exchangeable and carbonate-bound fractions of Cu in the soil reduced by 8.19% and 2.33%, and the readily reducible iron- and manganese-bound fractions of Cu increased by 8.00% and 2.69%, respectively, when treated with LS and MF. The risk of secondary activation of heavy metals was higher in soil treated with LS and MF than in soil treated with other amendments. The readily reducible iron- and manganese-bound fractions of Cu reduced by 2.21% and 5.90% and the organic-bound fractions of Cu increased by 4.75% and 3.48% when treated with BC and Fe-BC, respectively. This indicated that the immobilization effect tends to be stable. The exchangeable and carbonate-bound fractions of Cd in the soil decreased by 7.64%, 8.34%, 2.37%, and 6.73%, and the residual fractions increased by 8.27%, 9.18%, 5.73%, and 9.60% respectively, indicating that the amendment treatments resulted in better stability of Cd than Cu. The Cu and Cd contents of soil colloids were 489.92 mg ·kg-1 and 2.57 mg ·kg-1, respectively, which were considerably higher than those in soil (239.98 mg ·kg-1 and 1.93 mg ·kg-1, respectively). The amorphous iron oxide-bound Cu and Cd contents of soil colloids increased significantly with the application of each of the four amendment, which was the main reason and mechanism for the decrease in heavy metal bioavailability. With the extension of aging time, long-term immobilization can be achieved if the heavy metals are further transformed into crystalline iron oxide-bound and residual fractions.

[Regulation and Mechanism of a Dregs Biochar Matrix Combined with Maifanite on a Soil-Ryegrass System].

An indoor pot experiment and isothermal adsorption experiment were used to examine the regulation of soil-ryegrass system treatments. For the treatments, Banlangen dregs were selected as a raw material alongside two kinds of biochar (BC300, BC500) prepared by pyrolysis at 300℃ and 500℃ under anoxic conditions. Fe was modified by BC500 (Fe-BC500), which was then combined with maifanite (MFS) as a passivating agent[BC500:MFS (1:1) and Fe-BC500:MFS (1:1)]. Surface pore distribution (BET), scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR) were used in the analyses. The results showed that treatment with BC300, BC500, Fe-BC500, MFS, BC500:MFS (1:1), and Fe-BC500:MFS (1:1) significantly reduced the Cu and Cd content (2% content in soil) of ryegrass (P<0.05) and significantly increased the biomass of ryegrass. This effect could have resulted from the enhanced chlorophyll content and root activity of the ryegrass. The effect of BC300 was better than the other treatments, which reduced the content of Cu and Cd in the roots of ryegrass by 44.78% and 63.89%, respectively, and in the aboveground biomass by 76.34% and 53.40%, respectively. The biomass of roots was also increased by 327.22%, and the aboveground biomass increased by 504.11%. The Langmuir equation produced the best fit for adsorption effects of BC300, BC500, and Fe-BC500, for which the maximum adsorption capacity for Cu was 8.02, 9.20, and 8.82 mg·g-1, respectively. The maximum adsorption capacity for Cd was 7.97, 8.51, and 7.70 mg·g-1, respectively. The Freundlich equation gave a better fit for the adsorption of MFS. In this case, the maximum adsorption capacity for Cu and Cd was 7.03 mg·g-1 and 6.10 mg·g-1, respectively. BC300 and BC500 mainly passes through their surface hydroxyl, carboxyl, carbonyl, and ester groups; Fe-BC500 mainly passes through its surface hydroxyl group and iron hydroxyl group; MFS mainly passes through its silicon hydroxyl group, hydroxyl group, and carboxyl group on the surface of NaAlSi3O8 and Al2Si2O5(OH)4 and then to repair passivated Cu and Cd contaminated soil effect. Therefore, Banlangen dregs biochar, iron-modified Banlangen dregs biochar, maifanite, and the combination of these materials can be used for the remediation of Cu and Cd contaminated soils, although the mechanism of remediation is different.

[Dynamic pathologic changes in pigs infected with Taenia solium].

Four three-way crossed hybrid pigs were infected each with 80,000 Taenia solium eggs. One pig was sacrificed respectively at 40, 80, 120, and 150 d post-infection, and tissue samples containing cysticerci were collected for pathological sections. The results showed that in 40-80 days, cysticerci in the liver were surrounded by membrane formed with the hyperplastic fibrous connective tissue and inflammatory cells. On 120th day, a large number of the cysticerci were dead or calcified. On 150th day, all cysticerci died or calcified. On 40th, day, the inflammatory cells infiltrated around the cysticerci in the tongue and skeletal muscle, and the inflammatory responses near the scolex were more serious than that near cyst wall. In the 80-150 days, the inflammatory cells showed band like distribution. The pathological response in cardiac muscle was similar to that of the skeletal muscle and the tongue, but with more inflammatory cells. On 40th day, there were a few inflammatory cells infiltrating around cysticerci in the brain, in the 80-150 days, a large number of inflammatory cells aggregated around the cysticerci. The inflammatory response in the tissues progressed with the duration of infection and the inflammation in the liver was significantly stronger than that in other tissues.

[Total protein analysis by two-dimensional electrophoresis in cysticerci of Taenia solium and Taenia asiatica].

Two 20-day-old three-way crossed hybrid pigs were infected with 80000 Taenia solium or T. asiatica eggs, respectively. Immature cysticerci of the two species in liver were collected at 40 days after infection. The total proteins were separated by two-dimensional electrophoresis, and differentially expressed proteins were analyzed by Image-Master 2D Platinum 6.0 software. The results showed that there were (236 +/- 12) and (231 +/- 14) protein spots in 2D electrophoresis gel images of T. solium and T. asiatica, respectively, with 3 proteins up-regulated and 7 proteins down-regulated in T. solium cysticercus by 2-fold or more compared with those in T. asiatica cysticercus.

[Screening, identification and bioinformatic analysis of Taenia solium cysticercus].

OBJECTIVE: To screen and identify specific antigens of Taenia solium cysticercus, and predict the function of target proteins using bioinformatics method. METHODS: Patients infected with Taenia solium were dewormed by decoction arecae and pumpkin seeds to collect worms, and eggs were then prepared. Six three-way crossed hybrid pigs were randomly divided into experimental group and control group, and each experimental pig was infected with 80,000 T. solium eggs. Serum samples were collected at 40 days after infection. The total protein of T. solium cysticercus was separated by two-dimensional electrophoresis, and Western blotting was performed to find out distinct antigens. Proteins from the two groups were identified by ESI-Trap MS. Query in NCBI database was made to confirm function of the proteins. RESULTS: 207+/-9 spots were detected through Coomassie brilliant blue-stained gels with Mr 14,400-94,000 and pI 3.0-10.0. Western blotting showed 7 specific antigen spots with pool sera of infected pigs. Four of the 7 antigens with known functions were respectively ascribed to cytoskeletal actin-2 (adult-specific), tropomyosin (cysticercus-specific), AF239799-1 annexin (cysticercus-specific) and actin-1 (cysticercus-specific). CONCLUSIONS: Three specific antigens of Taenia solium cysticercus have been identified.