Leaching of As and Se from coal fly ash: fundamental study for coal fly ash recycling.

Coal fly ash (CFA) is a useful recycled resource for uses such as cement raw material. To manage and evaluate safety for effective utilization of CFA, the leaching concentration and amounts of toxic elements in CFA need to be determined. In this study, 38 types of CFA and aged CFA generated in Japan were used to measure the occurrence and leaching concentration range of As and Se. In addition, the leaching characteristics over the long term were examined using statistical analysis. Leaching concentrations of As and Se from CFAs were in the range of 0.001-0.163 mg/L (average: 0.025 mg/L, median: 0.014 mg/L) and 0.001-0.189 mg/L (average: 0.071 mg/L, median: 0.055 mg/L), respectively. In general, the concentrations of aged CFAs were less than those of the CFAs with a few exceptions. Leaching concentrations of As and Se in the tank leaching test changed with time, and As and Se concentrations in the dispersions increased with stirring time. In contrast, pH of the dispersion decreased with time. The relation between As or Se and CFA factors showed that As or Se and pH or Ca were highly correlated. However, in aged CFAs for long-term use, the correlation coefficient for the relation between As and other factors was low while that for Se-S was high. Considering the effective utilization of CFA as a long-term recyclable resource, the leaching processes of As and Se in CFA would change with time depending on the environmental conditions.

Muraminomicins, new lipo-nucleoside antibiotics from Streptosporangium sp. SANK 60501-structure elucidations of muraminomicins and supply of the core component for derivatization.

We screened for bacterial phospho-N-acetylmuramyl-pentapeptide-translocase (MraY: EC 2.7.8.13) inhibitors with the aim of discovering novel antibiotics and observed inhibitory activity in the culture broth of an actinomycete, SANK 60501. The active compounds, muraminomicins A, B, C, D, E1, E2, F, G, H, and I exhibited strong inhibitory activity against MraY with IC50 values of 0.0105, 0.0068, 0.0104, 0.0099, 0.0115, 0.0109, 0.0089, 0.0134, 0.0186, and 0.0094 µg ml-1, respectively. Although muraminomicin F exhibited favorable antibacterial activity against drug-resistant Gram-positive bacteria, this activity was reduced with the addition of serum. To efficiently supply the core component for chemical modification studies, production was carried out in a controlled trial by adding myristic acid to the medium, and a purification method suitable for large-scale production was successfully developed.

Classification of coal fly ash based on pH, CaO content, glassy components, and leachability of toxic elements.

Coal fly ash (CFA), a by-product generated from coal-burning power plants, readily leaches toxic elements into aquatic environments. The present study describes a classification system for CFA based on the chemical composition of CFA and leachability of toxic elements, which can promote the safe and effective utilization of CFA for uses such as fly ash cement. To classify CFA samples, the CaO content, leachate pH, leachability of toxic elements such as B, As, and Se, and the acid- and alkali-soluble Si and Al in glassy components were determined for ten types of CFA samples produced in Japan. The results indicated that the CFA samples could be grouped into three groups: group A, which was characterized by low CaO content, low leachate pH, and a relatively high amount of alkaline-soluble Al; group B, which was characterized by low CaO content, low leachate pH, and relatively low amount of alkaline-soluble Al; and group C, which was characterized by high CaO content, high leachate pH, and relatively low amount of alkaline-soluble Al. Characteristic of group A CFA was the simultaneous leaching of Al and the minor elements along with a gradual increase in pH. This type of CFA carries the risk of leaching toxic substances upon contact with alkali solutions. These results can aid the discovery and separation of safe and unsafe CFA, allowing the safe CFA to be used in cement to produce concrete under alkali conditions.

Mobility and natural attenuation of metals and arsenic in acidic waters of the drainage system of Timok River from Bor copper mines (Serbia) to Danube River.

Bor, Krivelj, and Bela Rivers belong to the watershed of Timok River, which is a tributary of transboundary Danube River. These rivers receive metal-rich acidic wastewater from metallurgical facilities and acid mine drainage (AMD) from mine wastes around Bor copper mines. The aim of this study was to determine the mobility and natural attenuation of metals and arsenic in rivers from Bor copper mines to Danube River during the year 2015. The results showed that metallurgical facilities had the largest impact on Bor River by discharging about 400 t of Cu per year through highly acidic wastewater (pH = 2.6). The highest measured concentrations of Cu in river water and sediments were 40 mg L-1 and 1.6%, respectively. Dissolution of calcite from limestone bedrock and a high concentration of bicarbonate ions in natural river water (about 250 mg L-1) enhanced the neutralization of acidic river water and subsequent chemical precipitation of metals and arsenic. Decreases in the concentrations of Al, Fe, Cu, As, and Pb in river water were mainly due to precipitation on the river bed. On the other hand, dilution played an important role in the decreases in concentrations of Mn, Ni, Zn, and Cd. Chemically precipitated materials and flotation tailings containing Fe-rich minerals (fayalite, magnetite, and pyrite) were transported toward Danube River during the periods of high discharge. This study showed that processes of natural attenuation in catchments with limestone bedrock play an important role in reducing concentrations of metals and arsenic in AMD-bearing river water.

A Novel Fusion Protein, AChR-Fc, Ameliorates Myasthenia Gravis by Neutralizing Antiacetylcholine Receptor Antibodies and Suppressing Acetylcholine Receptor-Reactive B Cells.

Most patients with myasthenia gravis (MG) have elevated levels of autoantibodies against the nicotinic acetylcholine receptor (AChR) at the neuromuscular junction, which leads to muscle weakness. We developed a fusion protein, AChR-Fc, as a novel therapeutic biomolecule for patients with MG and examined its efficacy. AChR-Fc was expressed by Chinese hamster ovary cells and purified. We examined the neutralizing activity and cellular cytotoxicity of AChR-Fc using anti-AChR antibody-producing hybridoma cells and serum samples from 16 patients with MG. The effects of AChR-Fc in vivo were also examined using rat MG models. AChR-Fc bound to anti-AChR antibodies and exhibited cytotoxicity against patient-derived antibody-producing B cells. Additionally, a dose-dependent improvement in the clinical signs of disease was observed in a rat MG model. AChR-Fc can diminish signs of MG by neutralizing anti-AChR antibodies and enhancing cytotoxicity against autoantibody-producing B cells. Thus, AChR-Fc can be a novel therapeutic biomolecule for patients with MG.

Machine-learning techniques for geochemical discrimination of 2011 Tohoku tsunami deposits.

Geochemical discrimination has recently been recognised as a potentially useful proxy for identifying tsunami deposits in addition to classical proxies such as sedimentological and micropalaeontological evidence. However, difficulties remain because it is unclear which elements best discriminate between tsunami and non-tsunami deposits. Herein, we propose a mathematical methodology for the geochemical discrimination of tsunami deposits using machine-learning techniques. The proposed method can determine the appropriate combinations of elements and the precise discrimination plane that best discerns tsunami deposits from non-tsunami deposits in high-dimensional compositional space through the use of data sets of bulk composition that have been categorised as tsunami or non-tsunami sediments. We applied this method to the 2011 Tohoku tsunami and to background marine sedimentary rocks. After an exhaustive search of all 262,144 (= 2(18)) combinations of the 18 analysed elements, we observed several tens of combinations with discrimination rates higher than 99.0%. The analytical results show that elements such as Ca and several heavy-metal elements are important for discriminating tsunami deposits from marine sedimentary rocks. These elements are considered to reflect the formation mechanism and origin of the tsunami deposits. The proposed methodology has the potential to aid in the identification of past tsunamis by using other tsunami proxies.

The fate of arsenic in a river acidified by volcanic activity and an acid thermal water and sedimentation mechanism.

The Shozu-gawa river, located in the Aomori Prefecture, northern Japan, is affected by volcanic activities and acid thermal waters. The river is unique because both solid arsenic (As; as orpiment, As2S3) and dissolved As are supplied to the river from the uppermost caldera lake (Usori-ko Lake) and thermal ponds. The watershed is an excellent site for investigating the fate of different As species in a fluvial system. Upstream sediments near the caldera lake and geothermal ponds are highly contaminated by orpiment. This solid phase is transported as far as the mouth of the river. On the other hand, dissolved As is removed from the river system by hydrous ferric oxides (HFOs); however, HFO formation and removal of dissolved As do not occur in the uppermost area of the watershed, resulting in further downstream transport of dissolved As. Consequently, upstream river sediments are enriched in orpiment, whereas As(v), which is associated with HFOs in river sediments, increases downstream. Furthermore, orpiment particles are larger, and possibly heavier, than those of HFO with sorbed As. Fractionation between different chemical states of As during transport in the Shozu-gawa river is facilitated not only by chemical processes (i.e., sorption of dissolved As by HFOs), but also by physical factors (i.e., gravity). In contrast to acid mine drainage (AMD), in some areas of the Shozu-gawa river, both solid forms of As (as sulfide minerals) and dissolved As are introduced into the aquatic system. Considering that the stabilities of sulfide minerals are rather different from those of oxides and hydroxides, river sediments contacted with thermal waters possibly act as sources of As under both aerobic and anaerobic conditions.

Immobilization of B, F, Cr, and As in alkaline coal fly ash through an aging process with water.

Fourteen different alkaline coal fly ashes (CFAs) were used for the experiment, in which each sample was mixed with water to be 28.6% of water content (wt/wt) and aged for 1-4 weeks at 10-30 °C. This simple treatment is advantageous for decreases in water-soluble B, F, Cr, and As. Compared to non-aged CFAs, their water-soluble fractions remained 0.56-88%, 21-85%, 0.37-93% and 2.6-88%, respectively, after aging for a week at 20 °C, although the amounts of Cr and As released from some CFA samples increased. Considering the significant decrease in elution of sulfate, Ca and Al after aging, the immobilization, namely prevention of toxic element elution, could be related to formation of secondary minerals such as portlandite, gypsum and ettringite. Immobilization of B and Cr tends to proceed preferentially under colder conditions. Aging at higher temperatures enhances the leachability of Cr in some CFA samples. Contrary to the behavior of B and Cr, water-soluble F effectively decreases under warmer conditions.

Genome-Wide Gene Expression Profiling Revealed a Critical Role for GATA3 in the Maintenance of the Th2 Cell Identity.

Functionally polarized CD4+ T helper (Th) cells such as Th1, Th2 and Th17 cells are central to the regulation of acquired immunity. However, the molecular mechanisms governing the maintenance of the polarized functions of Th cells remain unclear. GATA3, a master regulator of Th2 cell differentiation, initiates the expressions of Th2 cytokine genes and other Th2-specific genes. GATA3 also plays important roles in maintaining Th2 cell function and in continuous chromatin remodeling of Th2 cytokine gene loci. However, it is unclear whether continuous expression of GATA3 is required to maintain the expression of various other Th2-specific genes. In this report, genome-wide DNA gene expression profiling revealed that GATA3 expression is critical for the expression of a certain set of Th2-specific genes. We demonstrated that GATA3 dependency is reduced for some Th2-specific genes in fully developed Th2 cells compared to that observed in effector Th2 cells, whereas it is unchanged for other genes. Moreover, effects of a loss of GATA3 expression in Th2 cells on the expression of cytokine and cytokine receptor genes were examined in detail. A critical role of GATA3 in the regulation of Th2-specific gene expression is confirmed in in vivo generated antigen-specific memory Th2 cells. Therefore, GATA3 is required for the continuous expression of the majority of Th2-specific genes involved in maintaining the Th2 cell identity.

Paraoxonase-1 suppresses experimental colitis via the inhibition of IFN-γ production from CD4 T cells.

Crohn's disease (CD) is a chronic inflammatory disorder of the gastrointestinal tract, where excessive Th1 cell responses are observed. We performed experiments to identify immunologically bioactive proteins in human plasma and found that paraoxonase (PON)-1, which has esterase activity and is associated with high-density lipoproteins, inhibited the IFN-γ production by both murine and human differentiating Th1 cells. Trinitrobenzene sulfonic acid-induced colitis was attenuated by the administration of PON-1. The beneficial effects of PON-1 were associated with a reduced ratio of IFN-γ-producing CD4 T cells in the mesenteric lymph nodes and decreased production of T cell-related cytokines in the colon. PON-1 inhibited the TCR-induced activation of ERK-MAPK signaling and the nuclear translocation of NF-κB in CD4 T cells. Interestingly, an excessive CD4 T cell response was observed in PON-1-deficient mice under physiological and pathological conditions. Additionally, the efficacy of PON-1 or G3C9-C284A (G3C9), which shows a higher esterase activity than PON-1, on colitis was similar to that of an anti-TNF-α mAb, which is a clinically used CD treatment. Moreover, G3C9 more effectively suppressed CD4(+)CD45RB(high) cell transfer-induced chronic colitis in mice than did PON-1, and the efficacy of G3C9 against the colitis was similar to that of the anti-TNF-α mAb. Therefore, PON-1 (or G3C9) administration may be clinically beneficial for CD patients.

Seasonal and spatial distribution of trace elements in the water and sediments of the Tsurumi river in Japan.

The Tsurumi, a class-one Japanese river, has a significant metal loading originating from urban environment. Water and sediment samples were collected from 20 sites in winter and summer, 2009 and were analyzed to determine and compare the extent of different trace element enrichment. A widely used five-step sequential extraction procedure was also employed for the fractionation of the trace elements. Concentrations of zinc, copper, lead, chromium, and cadmium were three to four times higher than that of reference values and downstream sediments are much more polluted than the upstream sites. Geochemical partitioning results suggest that the potential trace metal mobility in aquatic environment was in the order of: cadmium > zinc > lead > copper > cobalt > chromium > molybdenum > nickel. About 80.2% zinc, 77.9% molybdenum, 75.3% cobalt, 63.7% lead, 60.9% copper, 55.1% chromium, and 39.8% nickel in the sediment were contributed anthropogenically. According to intensity of pollution, Tsurumi river sediments are moderately to heavily contaminated by zinc, lead, and cobalt. Enrichment factor values demonstrated that zinc, lead, and molybdenum have minor enrichment in both the season. The pollution load index (PLI) has been used to access the pollution load of different sampling sites. The area load index and average PLI values of the river were 7.77 and 4.93 in winter and 7.72 and 4.89 in summer, respectively. If the magnitude of pollution with trace metal in the river system increases continuously, it may have a severe impact on the river's aquatic ecology.

A-90289 A and B, new inhibitors of bacterial translocase I, produced by Streptomyces sp. SANK 60405.

During the course of screening for translocase I inhibitors, the new liposidomycin-related compounds, A-90289 A and B, were isolated from a culture broth of Streptomyces sp. SANK 60405. The structural elucidations were carried out by NMR and high-resolution mass spectral analyses, and they were classified as members of the liponucleoside antibiotics group with a sulfate group at the C-2' position. A-90289 A and B inhibited bacterial translocase I with IC(50) values of 36.5 ng ml(-1) and 33.8 ng ml(-1), respectively.

Application of a dynamic reaction cell (DRC) ICP-MS in chromium and iron determinations in rock, soil and terrestrial water samples.

Despite environmental and geochemical interests, Cr and Fe have been left beyond the reach of determinations by ICP-MS due to severe interferences originating from Ar. The applicability of a dynamic reaction cell (DRC)-ICP-MS has been examined for determinations in environmental and geochemical samples. The reaction with NH(3) in the DRC system provides an eligible technique to determine Cr, because of a greater improvement in the signal/noise (S/N) ratio due to an effective elimination of interferences arising from Ar (ArC, ArN and ArO), and makes it possible to analyze Cr even at sub-microg L(-1) levels. As compared to non-DRC mode analyses, the DRC technique using m/z 56 appeared to be preferable for Fe determination in most terrestrial waters because of effective suppression of (40)Ar(16)O(+). In addition, the effects of cluster ions, such as (39)K(14)N(1)H(3)(+) and (40)Ca(14)N(1)H(2)(+), on Fe determination were also negligibly small. Measurements using (54)Fe by the DRC mode are also advantageous for Ca-rich samples, such as limestone and dolomite.

Haplofungins, novel inositol phosphorylceramide synthase inhibitors, from Lauriomyces bellulus SANK 26899 I. Taxonomy, fermentation, isolation and biological activities.

In the course of screening for antifungal agents, we have discovered eight novel compounds, haplofungin A, B, C, D, E, F, G and H, from a culture broth of the fungus strain Lauriomyces bellulus SANK 26899. Haplofungins are composed of an arabinonic acid moiety linked through an ester to a modified long alkyl chain and show potent inhibitory activities against fungal inositol phosphorylceramide (IPC) synthase. Haplofungin A inhibited the activity of IPC synthase from Saccharomyces cerevisiae with an IC(50) value of 0.0015 microg ml(-1). This inhibitor also suppressed the growth of Candida glabrata at the MIC value of 0.5 microg ml(-1).

Studies on novel bacterial translocase I inhibitors, A-500359s. I. Taxonomy, fermentation, isolation, physico-chemical properties and structure elucidation of A-500359 A, C, D and G.

In the course of our screening for bacterial phospho-N-acetylmuramyl-pentapeptide-translocase (translocase I: EC 2.7.8.13) inhibitors, we found inhibitory activity in the cultured broth of the strain identified as Streptomyces griseus SANK 60196. The strain produced capuramycin and four novel capuramycin derivatives designated as A-500359 A, C, D and G. Purification and structural analysis were performed, and the structures of A-500359 A, C, D and G were elucidated as 6'''-methylcapuramycin, 3'-demethyl-6'''-methylcapuramycin, 2''-deoxy-6'''-methylcapuramycin and 3'-demethylcapuramycin, respectively.

Studies on novel bacterial translocase I inhibitors, A-500359s. III. Deaminocaprolactam derivatives of capuramycin: A-500359 E, F, H; M-1 and M-2.

Novel derivatives of capuramycin were obtained when 10 mM of 2-aminoethyl-L-cysteine (AEC), an inhibitor of aspartokinase, was added to the culture of Streptomyces griseus SANK 60196, the producer of A-500359. They were purified from the culture filtrate and their chemical structures were elucidated as a deaminocaprolactam derivative of capuramycin designated as A-500359 F, A-500359 E, a methyl ester of A-500359 F, and A-500359 H, a 3'-demethyl derivative of A-500359 F. Two other compounds, A-500359 M-1 and A-500359 M-2, were purified from the same medium and their structures were elucidated. A-500359 E, F, H, M-1 and M-2 inhibited bacterial translocase I with an IC50 of 0.027 microM, 1.1 microM, 0.008 microM, 0.058 microM and 0.010 microM, respectively. A-500359 E, M-1 and M-2 inhibited the growth of mycobacteria as well.