Dual role of O2 concentration on the reducing gases produced and NO reduction during sewage sludge combustion in pilot scale cement precalciner.

The reducing gases produced and NO reduction by sewage sludge combustion were investigated in a self-made cement precalciner. The dual role of O2 concentration (0-5 vol%) in the production characteristics of reducing gases and the reduction efficiency of NO were evaluated experimentally. TG-FTIR analysis demonstrated that the key reducing gaseous species produced by sewage sludge combustion were HCN, NH3, CO, and CH4. And experiments demonstrated that O2 concentration had pronounced effects on NH3 distribution, the maximum production rate was obtained at an O2 concentration of 3 vol%. Meanwhile, the reducing gases NH3 and CO were the key species for NO reduction in the cement precalciner, and the reduction efficiency of NO, when reduced by NH3, increased with an increase in O2 concentration, while the reduction performance of NO by CO was limited by O2 concentration. Therefore, O2 concentration greatly influences NO reduction efficiency by sewage sludge combustion; the maximum NO reduction efficiency was 61.67% at an O2 concentration of 3 vol%. The difference in NO reduction by sewage sludge combustion under different O2 concentrations was primarily attributed to NH3 production rate and NO reduction by NH3 and CO, which is greatly affected by O2 concentration. Sewage sludge combustion can result in NO reduction in the cement kiln flue gas and resource utilisation of sewage sludge.

CyanoPATH: a knowledgebase of genome-scale functional repertoire for toxic cyanobacterial blooms.

CyanoPATH is a database that curates and analyzes the common genomic functional repertoire for cyanobacteria harmful algal blooms (CyanoHABs) in eutrophic waters. Based on the literature of empirical studies and genome/protein databases, it summarizes four types of information: common biological functions (pathways) driving CyanoHABs, customized pathway maps, classification of blooming type based on databases and the genomes of cyanobacteria. A total of 19 pathways are reconstructed, which are involved in the utilization of macronutrients (e.g. carbon, nitrogen, phosphorus and sulfur), micronutrients (e.g. zinc, magnesium, iron, etc.) and other resources (e.g. light and vitamins) and in stress resistance (e.g. lead and copper). These pathways, comprised of both transport and biochemical reactions, are reconstructed with proteins from NCBI and reactions from KEGG and visualized with self-created transport/reaction maps. The pathways are hierarchical and consist of subpathways, protein/enzyme complexes and constituent proteins. New cyanobacterial genomes can be annotated and visualized for these pathways and compared with existing species. This set of genomic functional repertoire is useful in analyzing aquatic metagenomes and metatranscriptomes in CyanoHAB research. Most importantly, it establishes a link between genome and ecology. All these reference proteins, pathways and maps and genomes are free to download at http://www.csbg-jlu.info/CyanoPATH.

Effect of Ca(OH)2 on the Release Characteristics of HCl during Sludge Combustion.

With the addition of Ca(OH)2, the effects of combustion temperature, moisture, sludge particle size, and chlorine-containing additives on the removal of HCl during sludge combustion were studied. The experimental results showed that combustion temperature and moisture content promoted the formation of HCl and Ca(OH)2 played a key role in the formation of HCl during sludge combustion. Under the best conditions of a sludge particle size of 380-250 µm, moisture content of 5%, temperature of 850 °C, and Ca(OH)2/sludge weight ratio of 3/10, the HCl capture efficiency was 79.81%. In addition, the effect of PVC on the production of HCl was greater than that of NaCl, probably because the lattice energy of NaCl was much higher, indicating that inorganic chlorine was not the main source of HCl. Ca(OH)2 can effectively inhibit the formation of HCl, which had practical guiding significance for the formation of HCl during the sludge combustion, especially the sludge containing chlorine.

Alteration of microRNA expression in vinyl carbamate-induced mouse lung tumors and modulation by the chemopreventive agent indole-3-carbinol.

MicroRNAs (miRNAs) are small, non-protein-coding RNAs that can function as tumor suppressors or oncogenes. Deregulation of miRNA expression has been reported in lung cancer. However, modulation of miRNA expression by chemopreventive agents remains to be defined. In the present study, we examined if the chemopreventive agent indole-3-carbinol (I3C) reversed vinyl carbamate (VC)-induced deregulation of miRNA levels in lung tissues of female A/J mice. Lung tissues were obtained from a previous chemoprevention study, in which mice were treated with VC and given I3C in the diet for 15 weeks. Microarray studies revealed alterations in the expression of a number of miRNAs in lung tumors relative to that of normal lungs. miR-21, mir-31, miR-130a, miR-146b and miR-377 were consistently upregulated, whereas miR-1 and miR-143 were downregulated in lung tumors relative to normal lungs. In mice treated with VC and given I3C in the diet, levels of miR-21, mir-31, miR-130a, miR-146b and miR-377 were reduced relative to the level in mice treated with the carcinogen only. The results of the microarray study were confirmed by quantitative reverse transcription-polymerase chain reaction and gel analysis of polymerase chain reaction products. Further studies with miR-21 indicated that phosphatase and tensin homolog, programmed cell death 4 and rich protein with Kazal motifs are potential targets for the oncogenic effect of miR-21 and the chemopreventive activity of I3C. Taken together, we showed here that miRNAs are deregulated during VC-induced mouse lung tumorigenesis and their levels are modulated by I3C. Therefore, miRNAs and their target genes are promising biomarkers for the diagnosis of lung cancer and efficacy of chemopreventive/chemotherapeutic agents.

Stripping custom microRNA microarrays and the lessons learned about probe-slide interactions.

Microarrays have been used extensively in gene expression profiling and genotyping studies. To reduce the high cost and enhance the consistency of microarray experiments, it is often desirable to strip and reuse microarray slides. Our genome-wide analysis of microRNA expression involves the hybridization of fluorescently labeled nucleic acids to custom-made, spotted DNA microarrays based on GAPSII-coated slides. We describe here a simple and effective method to regenerate such custom microarrays that uses a very low-salt buffer to remove labeled nucleic acids from microarrays. Slides can be stripped and reused multiple times without significantly compromising data quality. Moreover, our analyses of the performance of regenerated slides identifies parameters that influence the attachment of oligonucleotide probes to GAPSII slides, shedding light on the interactions between DNA and the microarray surface and suggesting ways in which to improve the design of oligonucleotide probes.

[Recruitment dynamics of bloom-forming cyanobacteria in Meiliang Bay of Taihu Lake].

A collection trap was installed on the sediments in Meiliang Bay of Taihu Lake during the period from March to June to investigate the recruitment of phytoplankton, and cyanobacteria in particular. The algal abundance in the trap was monitored, and compared with that in water column and surface sediments. The results showed that the algal recruitment was related to the temperature, irradiance, DO content, and oxidation-reduction potential (ORP) in surface sediment. After over-wintering on the sediments, the colonies of cyanobacteria experienced a prior developmental process before re-invasion of the water column. During the investigation period, the recruitment rates of chlorophyll a and b and PC were 59.84 %, 76.83 % and 466.98%, and the recruitment amounts accounted for 7.18%, 3.71% and 9.33% of their maximum pelagic counterparts in water column, respectively. These results showed that shallow lake was the important seed bank to the pelagic populations, and water bloom was formed as the result of the recruitment and biomass accumulation of cyanobacteria.

[The application of the gene-recombinated cell in the detection of PCBs compounds in environmental samples].

To develop novel and rapid bioassay systems for detection of PCBs in environmental and biological samples, two lines of gene-recombinated cells containing reporter gene, green fluorescent protein (GFP) and luciferase (Luc), were be chosen to detect the PCBs in the water, sediment and biological samples from environment. The result showed that the correlation between RFU of GFP and Luc activity and PCBs standard sample concentration was fine, r was 0.99188 and 0.98239 respectively. Compared with the instrument analysis with GC-ECD, the correlation between RFU of GFP and Luc activity and PCBs concentration in environmental and biological extracts was also fine. The method offered a new way of screening and semi-quantitative bioassay for PCBs compounds in environmental and biological samples.

[Effects of neem seed extracts on nitrogen use efficiency in two different soils].

Incubation test and pot experiments were conducted with haplic luvisols and hydragric anthrosols to study the effects of neem seed extracts (N I, N II) on nitrification and immobilization of ammonium sulfate. N I could significantly inhibit the nitrification of N applied to the two soils. N II was effective in promoting the immobilization of NH4+(-)N. Pot experiments showed that N II could increase the use efficiency of chemical nitrogen significantly in fimic anthrosols.