[Modified Biochar for Remediation of Soil Contaminated with Arsenic and Cadmium: A Review].

Binary pollution of arsenic (As) and cadmium (Cd) has become the main soil environmental problem in China. As an adsorbent or immobilizer, modified biochar is playing an increasing role in the remediation of As and Cd-contaminated soil. Here, the limitations regarding the primitive biochar as an immobilizer for the remediation of As and Cd-contaminated soil were highlighted by this study. Meanwhile, the biochar modification methods for the remediation of As and Cd-contaminated soil were reviewed, and the main interaction mechanisms were analyzed. Finally, the prospects and questions for the future remediation of soil contaminated with As and Cd using modified biochar were proposed. The results showed that metal-modified biochar had a better synergistic effect on the remediation of As and Cd-contaminated soil and thus had better application prospects. The immobilization mechanisms of As and Cd using biochar material remediation were affected by its modification methods. For example, the mechanisms for (non)metal-modified biochar involved the functional group-induced bonding complexation, co-precipitation, and oxyanion As redox; for microorganism-modified biochar, the mechanisms were precipitation and As redox, and those for physical- and acid-modified biochar only included the physical adsorption and weak electrostatic attraction. In view of the limitations of present research on the application of modified biochar for the remediation of As and Cd-contaminated soil, future research is suggested to study the following:① the effect of biomass feedstock type, pyrolysis temperature, preparation conditions, cost, and soil aging; ② evaluation for stability and durability of heavy metal immobilization by modified biochar remediation under different environmental factors; and ③ insight to key remediation mechanisms of As and Cd-contaminated soil by material.

[Effects of Earthworms/Biochar on Bacterial Diversity and Community in As-contaminated Red Soil].

Cerium-manganese modified biochar (MBC) combined with earthworms (Eisenia foetida) can immobilize arsenic (As) in red soils. In this study, high-throughput sequencing technology was used to explore the combined effects of MBC and E. foetida on bacterial diversity and community structure in As-contaminated red soils. The results showed that the single earthworm treatment had the highest diversity index, whereas the diversity index decreased in the single biochar or MBC treatment, indicating that earthworms can boost the growth of bacteria in the soil, and the addition of biochar/MBC all decreased the bacterial diversity of soils. When biochar/MBC was combined with earthworms, the diversity index increased to some degree. In terms of bacterial community structure, the relative abundance of Proteobacteria and Bacteroidetes increased significantly in each treatment, especially for MBC-earthworm treated soil, in which the relative abundance was increased by 17.08% and 329.47% for Proteobacteria and Bacteroidetes, respectively, compared to that in the control (CK). Otherwise, those abundances were decreased by 19.18% and 48.76%, respectively, for Acidobacteria and Chloroflexi. Correlation analysis results showed that the soil water-soluble As (WSAs) was negatively correlated with the relative abundances of Proteobacteria and Bacteroides (P<0.05) but was positively correlated with Acidobacteria and Chloroflexi (P<0.05), which indicated that with the decrease in WSAs in soils, the bacteria of Proteobacteria and Bacteroides reproduced rapidly, whereas the Acidobacteria and Chloroflexi were inhibited. Moreover, different treatments induced selective changes in the bacterial community, in which earthworms significantly promoted the proliferation of γ-Proteobacteria, Flavobacteriales, Aeromonadales, and Variovorax and earthworms improved the immobilization effect of As by promoting the growth of these bacteria.

[Cerium-manganese Modified Biochar Immobilizes Arsenic in Farmland Soils].

Loaded cerium and manganese modified biochar (MBC) was prepared by high temperature pyrolysis at 600℃, and three kinds of arsenic (As) contaminated soils were selected for remediation, including red soil, yellow soil, and purple soil with different basic properties. During the soil incubation experiment, the goal of this research was to investigate the influence of MBC as a stabilizer of the mobility of arsenic in these three soils after treated by biochar (BC) and MBC. The results revealed that the application of MBC resulted in a significant decrease of water soluble arsenic content in the three different kinds of soils. With the additional amount increasing, the stabilization efficiency of soil arsenic increased continuously. When the applied amount of MBC ranged from 1% to 10%, the stabilization efficiency of arsenic was in the range of 70%-99%. The corresponding stabilizing efficiencies of the red, yellow, and purple soils were 70.59%-94.72%, 75.24%-98.35%, and 76.53%-99.61%, respectively, after being treated by MBC at 1%-10%. At a higher addition of 10% MBC, the efficiency of stabilization reached 95%. On the contrary, the addition of unmodified biochar caused the activation and dissipation of As in soils. Comparatively speaking, according to the stabilization efficiency, the three soils ranked in this decreasing order:purple soil > yellow soil > red soil. It also illustrated that the addition of MBC into soils led to the conversion of active arsenic to stable ones in soil, indicating the conversion from non-specifically sorbed (F1) and specifically sorbed (F2) to well-crystallized hydrous oxides of Fe and Al (F4) and residual phases (F5), which reduced the mobility of arsenic in these soils. According to the analysis of scanning electron microscopy (SEM) and X-ray diffraction analysis, the immobilization of arsenic by MBC was strongly related to the successful loading of cerium-manganese oxide onto biochar. Therefore, MBC can be used to make suitable amendments to immobilize As in soils for remediation of arsenic-contaminated farmland soils.

[Accumulation Characteristics of Heavy Metals in Greenhouse Soil and Vegetables in Siping City, Jilin Province].

Based on the typical greenhouse vegetable production system in Siping City, Jilin Province, 124 soil samples were collected from greenhouse soils growing vegetables (GSGV), fields growing maize (FGM), and forest soil (FS) under different land utilization patterns. In addition, other samples including greenhouse vegetables (81), fertilizers (50), and irrigation water (10) were also collected in the studied region. To illustrate the accumulation characteristics of heavy metals in GSGV and greenhouse vegetables, the heavy metal content of different samples was measured using inductively coupled plasma mass spectrometry (ICP-MS) technology. The results indicated that the heavy metal content in GSGV was much higher than that in FGM and FS except for lead (Pb). Heavy metals including cadmium (Cd), copper (Cu), chromium (Cr), nickel (Ni), and zinc (Zn) in GSGV presented with various degrees of accumulation. The mean value of Cd content in the soils in the investigation region was 0.45 mg·kg-1, with about 42.8% of all the soil samples exceeding the Cd content criterion of the Environmental Quality Evaluation Standard for Farmland in Greenhouse Vegetable Production (HJ 333-2006). The content of the other heavy metals was in the normal range, and all met the regulations of the standard. In comparison with different vegetable categories, leafy vegetables showed much higher heavy metal concentrations (Cd 0.033 mg·kg-1 fresh weight) than did fruity ones. In total, about 2.5% and 1.2% of vegetable samples exceeded the regulated values of Cd and Pb recommended by the Standard of Food limits, respectively. With the cultivation time prolonged, heavy metal concentration in soils and vegetables all increased synchronously as the pH value decreased. The content of heavy metals in greenhouse vegetables was significantly influenced by soil pH and organic matter. It can be concluded that the health risk of greenhouse vegetables increased with GSGV accumulating more heavy metals due to the substantial application of chemical fertilizer and manure containing high level of heavy metals.

[Effects of vegetable cultivation years on microbial biodiversity and abundance of nitrogen cycling in greenhouse soils].

The effects of facility vegetable cultivation years (three, nine, fourteen or seventeen years) on biodiversity and abundance of soil microorganisms, such as bacteria, ammonia oxidizing bacteria (AOB) and nirK type denitrifying bacteria, in the greenhouse soils in Wuwei of Gansu Province, China were determined by the combined analyses of terminal restriction fragment length polymorphism (T-RFLP) and real-time quantitative PCR. The results showed that the dominant population structure and abundance of bacteria, AOB, nirK type denitrifying bacteria in the soils were significantly different from those in the farmland fields. The dominant population also changed with the cultivation years. With the increase of vegetable cultivation years, the abundance of 16S rRNA and nirK gene in the 0-20 cm soil layer first increased and then decreased, with the maximum values of 9.67 x 10(9) and 2.30 x 10(7) copies x g(-1) soil at year 14 and year 9, being as 1.51 and 1.52 times of that of the 3-year, respectively. However, the abundance of amoA gene showed an opposite trend. The amoA gene copy number in the 14-year sample was 3.28 x 10(7) copies x g(-1) soil, which was only 45.7% of that of the 3-year. These results illustrated that the ecological adaptation mechanisms of the different functional microorganisms involved in nitrogen cycling had significant differences in the facility vegetable soils, and provided a base for further researches on exploring and explaining the characteristics and adaptation mechanisms of microorganisms in greenhouse soil.

[Effects of different fertilization regimes on abundance and community structure of the nirK-type denitrifying bacteria in greenhouse vegetable soils].

The community structure and abundance of nirK-type denitrifying bacteria in different soil layers (0-20 cm and 20-40 cm) under various fertilization regimes in Wuwei, Gansu Province were investigated by the combination of terminal restriction fragment length polymorphism (T-RFLP) and real-time quantitative PCR. Results showed that the nirK-type denitrifying bacteria community structure was significantly affected by fertilization regimes, especially for 70, 156 and 190 bp T-RFs that represented the dominant populations in greenhouse soil. Fertilization regimes significantly influenced the abundance of nirK gene in the 0-20 cm soil layer with the highest abundance of nirK gene copy number (2.16 x 10(7) copies x g(-1) soil) detected in the manure treatment (M), which was 2.04 and 2.02 times of that in the control (CK) and chemical fertilizer (NPK) treatments, respectively. Both the dominant population and abundance of nirK-type denitrifying bacteria in the greenhouse soil were significantly different between the 0-20 cm and 20-40 cm soil layers, and the nirK-type denitrifying bacteria community structure and abundance in the greenhouse soil were obviously different from that in the field. Soil pH, soil organic matter content and nitrate-N content had the greatest influence on the bacterial community composition. Phylogenetic analysis indicated that there were not only anaerobic nirK-type denitrifying bacteria in greenhouse soil, but also aerobic denitrifying bacteria, such as Rhizobium, Ochrobactrum, Agrobacterium.

Correlation between Duffy blood group phenotype and breast cancer incidence.

BACKGROUND: Different ethnicities have different distribution of Duffy blood group (DBG) phenotypes and different breast cancer morbidity. A study in our lab demonstrated that Duffy antigen/receptor for chemokines (DARC, also known as DBGP, the Duffy protein phenotype), led to the inhibition of tumorigenesis. Therefore, we tested the hypothesis that DBGP is correlated with breast cancer occurrence. METHODS: DBGP proteins were examined by indirect antiglobulin testing with anti-FYa and anti-FYb antibodies. The phenotypes were classified into four groups according to the agglutination reactions: FYa + FYb+, FYa + FYb-, FYa-FYb + and FYa-FYb-. The phenotypes and pathological diagnosis of consecutively hospitalized female patients (n = 5,022) suffering from breast cancer at the Shanghai Cancer Hospital and Henan Province Cancer Hospital were investigated. The relationships between DBGP expression with breast cancer occurrence, axillary lymph status, histological subtype, tumor size pathological grade and overall survival were analyzed. RESULTS: The incidence of breast cancer was significantly different between FYa + FYb + (29.8%), FYa + FYb- (33.2%), FYa-FYb + (45.6%) and FYa-FYb- (59.1%; P = 0.001). Significant different numbers of breast cancer patients had metastases to the axillary lymph nodes in the FYa + FYb + group (25.1%), FYa + FYb- (36.9%), FYa-FYb + (41.0%) and FYa-FYb- (50.0%, (P = 0.005). There was a statistical significance (p = 0.022) of the overall survival difference between patients with difference phenotypes. No significant difference was observed in cancer size (t-test, p > 0.05), histological cancer type (Fisher's exact test, p > 0.05) or histological grade (Fisher's exact test, p > 0.05) between every each DBGP group. CONCLUSIONS: DBGP is correlated with breast cancer incidence and axillary lymph node metastasis and overall survival. Further investigations are required to determine the underlying mechanism of Duffy blood group phenotype on breast cancer risk.

Rapid separation and identification of anthocyanins from flowers of Viola yedoensis and V. prionantha by high-performance liquid chromatography-photodiode array detection-electrospray ionisation mass spectrometry.

INTRODUCTION: Anthocyanins are important plant secondary metabolites. They show strong antioxidant activities and have potential as anti-cancer agents. Viola yedoensis and V. prionantha are traditional Chinese medicines and ornamental plants. However, the anthocyanin compositions of these two species are still unresolved. OBJECTIVE: To develop a rapid and reliable high-performance liquid chromatography (HPLC) method for the separation and identification of anthocyanins from V. yedoensis and V. prionantha. METHODOLOGY: Samples were extracted in methanol-water-formic acid-TFA (70:27:2:1, v/v). HPLC analysis was done on a C(18) column (TSK-GEL ODS-80Ts: 150 × 4.6 mm i.d.). Four solvent systems were tested to optimise the separation of anthocyanins using different gradient separation systems. HPLC-photodiode array detection (DAD) coupled to electrospray ionisation mass spectrometry (ESI-MS) was used to carry out the comprehensive characterisation of anthocyanins. RESULTS: Fourteen anthocyanins were characterised within 40 min with satisfactory peak resolution by a gradient composed of 10% aqueous formic acid and formic acid-acetonitrile-water (10:40:50, v/v). The calibration curve showed an excellent linear regression (r(2) = 0.9995) and low intra- and inter-day variations (RSD < 3.67%). The detected anthocyanins derived from Dp, Cy, Pt, Mv and Pn, could be divided into three groups: non-acylated glycosides, acetylglycosides and coumaroylglycosides. Anthocyanins distribution exhibited remarkable differences in aglycone levels and acylation patterns. CONCLUSION: The optimised method was successfully applied for the analysis of 14 anthocyanins from V. yedoensis and V. prionantha. The identification of anthocyanin constitutions is valuable for breeding and will open up new prospects for their medicinal application.

[Predictive value of (99)Tc(m)-MIBI scintimammography in evaluation of the efficacy of neoadjuvant chemotherapy in patients with operable breast cancer].

OBJECTIVE: To investigate the value of technetium-99m methoxyisobutylisonitrile ((99)Tc(m)-MIBI) imaging in predicting the efficacy of neoadjuvant chemotherapy (NCT) and prognosis in patients with operable breast cancer. METHODS: Sixty five patients with breast cancer underwent (99)Tc(m)-MIBI scintimammography before NCT, and static planar images were taken at 10 min and 180 min after scintimammography. The clearance rate was calculated in each patient, correlation between the clearance rate and efficacy of NCT, and the disease free survival rate were analyzed. RESULTS: The mean clearance rate of 65 patients was (17.4 ± 6.8)%. The efficacy of NCT was 86.2% (CR 4 cases, PR 52 cases, SD 8 cases, and PD 1 case), and the mean clearance rate of patients with good response or poor response of chemotherapy were (15.5 ± 5.0)% and (29.2 ± 3.2)%, respectively. There was a significant difference between the two groups. The average disease free survival rate in the group with low clearance rate was (75.8%, P = 0.046), significantly higher than that in the group with high clearance rate (53.1%). CONCLUSION: Scintimammography of (99)Tc(m)-MIBI may be used to evaluate the efficacy and prognosis of NCT for patients with operable breast cancer.

[Effects of exogenous dimethylarsinic acid on Brassica campestris growth and soil arsenic bioavailability].

A pot experiment was conducted to study the effects of exogenous dimethylarsinic acid (DMA) on the growth of Brassica campestris and the bioavailability of soil arsenic (As). With the increasing concentration of applied DMA, the emergence rate and biomass of B. campestris increased at low concentration DMA, but decreased at high concentration DMA. When the DMA concentration reached 90 mg x kg(-1), the emergence rate and biomass of B. campestris in the second cropping decreased by 9.5% and 57.0%, respectively, compared with those in the control, indicating that exogenous DMA had longer-term effects on the growth of B. campestris. The soil available As and the As uptake by B. campestris all increased with increasing concentration of exogenous DMA, and there existed significant correlations among them. After applied into soil, the exogenous DMA demethylated, with As(V) as the main product and lesser amount of As (III), and the concentrations of soil As(V) and As(III) increased with increasing application rate of exogenous DMA.

[Concentration and speciation of arsenic in greenhouse vegetable soil in Shouguang County of Shandong Province].

A sampling survey was conducted in the typical areas in Shouguang County of Shandong Province to study the characteristics of arsenic (As) concentration and speciation in greenhouse vegetable soil. The total As concentration in the surface (0-20 cm) and subsurface (20-40 cm) soil was averagely 8.27 and 7.93 mg x kg(-1), being 19% and 23% higher than that of the control (open field soil), and the soluble As (AE-As) concentration was 0.13 and 0.06 mg x kg(-1), 63% and 200% higher than that of the control, respectively. The ratio of residual As (O-As) to total arsenic reached more than 63.0%, and the concentrations of different As speciation decreased in the order of O-As > iron-bound As (Fe-As) > calcium bound As (Ca-As) > aluminum bound As (AlAs) > AE-As. With the increasing planting years, the AE-As concentration enhanced significantly, and the Al-As concentration also increased to some degree. After 15 years planting, the AE-As concentration in surface and subsurface soil increased by 75.0% and 150.0%, and Al-As concentration increased by 51.6% and 190.4%, respectively, while the concentrations of Fe-As and Ca-As all decreased to some degree.

[Effects of organic fertilization on arsenic absorption of pakchoi (Brassica chinensis) on arsenic-contaminated red soil].

A pot experiment with arsenic-contaminated red soil was conducted to study the effects of applying pig dung and chicken manure on the growth and arsenic absorption of pakchoi (Brassica chinensis), and on soil available arsenic. Applying pig dung and chicken manure to the arsenic-contaminated red soil increased the biomass of pakchoi to some extent. Comparing with the control, applying pig dung increased the pakchoi biomass significantly (P < 0.05). The soil available arsenic content after applying pig dung increased by 394.9%-1033.6% (P < 0.05), and that after applying chicken manure increased by 30.4%-94.1%. Organic fertilization promoted the arsenic absorption of pakchoi, with the arsenic uptake after applying pig dung increased by 20.7%-53.9%. The application of pig dung and chicken manure to arsenic-contaminated red soil could somewhat increase the soil available arsenic content and the arsenic uptake by crops, and thus, increase the risks of agricultural product quality and environment.

[Predicative value of 99mTc-MIBI scintimammography in neoadjuvant chemotherapeutic effect of patients with operable breast cancer].

OBJECTIVE: To evaluate the relationship between the clearance rate of technetium-99m methoxyisobutylisonitrile ((99m)Tc-MIBI) in scintimammography and the efficacy of neoadjuvant chemotherapy (NCT) of patients with operable breast cancer. METHODS: Seventy-eight patients with breast cancer underwent (99m)Tc-MIBI scintimammography at pre-NCT. And static planar images were taken at 10 min and 180 min post-scintimammography. The clearance rate was calculated in each patient. And the efficacy of NCT was evaluated after 2 cycles. RESULTS: The clearance rates of patients with a poor or good efficacy of chemotherapy were 24.21% ± 6.38% (n = 14) and 14.13% ± 5.98% (n = 64) respectively. There was significant difference between two groups. And a significant correlation was observed between the efficacy of chemotherapy and the clearance rate of (99m)Tc-MIBI (r = -0.539, P < 0.001). CONCLUSION: The scintimammography of (99m)Tc-MIBI may be employed to evaluate the efficacy of NCT.

[Soil arsenic content and its health risk assessment for agricultural products in the region surrounding Shimen arsenic sulphide mine].

A systematic investigation was carried out on the arsenic content in the soils and plants surrounding Shimen arsenic sulphide mine. The arsenic content in top soils (0-20 cm) was averagely 99.51 mg x kg(-1), being 5.34 times higher than that of the background value in Hunan Province and 8.70 times higher than that of local farmland soil. The topsoil arsenic content in paddy field and dry land was 43.51 and 115.1 mg x kg(-1), respectively, being 0.45 and 1.87 times higher than that of the grade II level (paddy field 30 mg x kg(-1); dry land 40 mg x kg(-1)) commended by the National Soil Quality (GB 15618-1995), and the corresponding arsenic exceeding rate was 62.5% and 50.0%, respectively. The arsenic content in edible parts of foodstuff, vegetables, and fruits was 0.16, 0.06, and 0.01 mg x kg(-1), respectively, and the arsenic exceeding rate of crop samples compared to food security standard ranked in the order of foodstuff > vegetables > fruits. Rice and sweet potato were relatively seriously contaminated by arsenic. The highest arsenic content of rice was up to 0.84 mg x kg(-1), which was 4.6 times higher than that of the National Standard, with the exceeding rate of 62.5%. Statistical analysis demonstrated that there was a positive correlation between the arsenic contents of soil and plant. The average daily intake of arsenic by local people through the consumption of the crops was 6.416 microg x kg(-1) x d(-1), which was much higher than the standard commended by WHO, and the related health risk index was 21.39, which was 14.39 times higher than that in the control region.

[Effects of exogenous dissolved organic matter and temperature on copper forms in red soil].

A simulating incubation test was conducted to evaluate the effects of exogenous dissolved organic matter (DOM) and incubation temperature on the copper forms in red soil. Comparing with the control, adding different amount of DOM increased the content of soil exchangeable Cu, but decreased the content of soil Fe-Mn bound Cu. With increasing time of incubation, the content of soil exchangeable Cu in all DOM-added treatments had a decreasing trend. By the end of the incubation, treatment 250 mg DOM x L(-1) had the highest contents of soil exchangeable Cu and carbonate bound Cu, while treatment 500 mg DOM x L(-1) had the highest content of soil Fe-Mn bound Cu. In the treatments with DOM addition, the content of soil organic bound Cu increased by 10.67%-23.66%, compared with the control. At incubation temperature 25 degrees C and 45 degrees C, the contents of soil exchangeable Cu and Fe-Mn bound Cu decreased with increasing time of incubation; while at 5 degrees C, an opposite trend was observed. At these three temperatures, the content of soil carbonate bound Cu in treatments with DOM addition increased with incubation time. The content of soil organic bound Cu increased with increasing temperature, but that of soil residual Cu decreased at lower temperature (5 degrees C).

[Influence of flooding on form transformation of soil arsenic].

An incubation test was conducted to study the dynamics of exogenously supplied dimethylarsenic acid (DMA), monomethylarsonic acid (MMA), and As(V) in soil under flooding. With the increasing time of incubation, the exogenously supplied DMA and MMA were mainly transformed into As(V), and the As(V) concentration increased, being significantly higher after incubated for 150 days, compared with that after incubated for 1 day. The exogenously supplied DMA was demethylated into As(V) within 30 days, accompanied by a little As(III), while the transformation rate of exogenously supplied MMA was rather slow within 60 days, accompanied by a little As(III) and DMA. The exogenously supplied As(V) decreased with increasing time of incubation, and its form had less change except that a little As(III) occurred.

[Transformation of exogenous dimethyl arsenic in soil].

A pot experiment was conducted to study the speciation transformation of exogenous dimethyl arsenic (DMA) in soil. The added DMA was mainly transformed into arsenate [As(V)], accompanied with a small amount of monomethyl arsenic (MMA). When the concentration of added DMA was 30 mg x kg(-1), the transformation rate was the highest, being 6.71%, 8.11%, 11.33%, and 19.32% when the cultivation time was 10, 15, 30, and 40 days, respectively. With increasing concentration of added DMA, soil soluble arsenic (AE-As) had an increasing trend, but decreased as the cultivation time increased. Comparing with CK, the addition of DMA increased the concentrations of soil arsenic bounded to aluminum (Al-As), iron (Fe-As), calcium (Ca-As), which was possibly due to the adsorption or fixation of added DMA and its transformation products by the oxides or hydroxides of soil aluminum, iron, and calcium.

[Transformation of different exogenous arsenic forms in soil under aerobic condition].

An incubation test was conducted to study the transformation of exogenous dimethylarsenic acid (DMA), monomethylarsenic acid (MMA), and arsenate [As(V)] in soil under the condition of 35% of water-holding capacity. After added into soil, the concentrations of test arsenic forms all showed a decreasing trend with time. The DMA and MMA were mainly demethylated, and after 120 days incubation at constant temperature and humidity, transformed into As(V). A small amount of MMA was detected in the treatment with added DMA on the 120th day of incubation, and a small amount of DMA was detected in the treatment with added MMA during the period of 7-60 days incubation. By the end of the incubation test, the concentrations of added DMA and MMA in soil decreased significantly (P < 0.01), with the decrement being 99.5% and 94.3% and the concentration of transformed As(V) increased by 4.61 and 5.15 times, respectively. Comparing with DMA and MMA, the As(V) after added into soil had less form transformation.