20 research outputs found
Emissions from co-firing lignite and biomass in an oxy-fired CFBC
The co-combustion of a high-sulfur lignite and biomass blend (up to 50% by weight) has been studied in a small oxy-fired circulating fluidized bed combustion (CFBC) pilot plant. Here the goal is to examine the effect of biomass share on NOx, SO2 and CO emissions. In these tests, a series of runs has looked at the effect of increasing biomass share under air firing, followed by tests in oxy-firing mode. The results show that the emissions are remarkably insensitive to the biomass share, and are comparable to other results for coal combustion, and likely to be well below any current emission guidelines. Overall, there appear to be no direct challenges to oxy-fuel co-firing in terms of gaseous emissions, although the simple lack of studies means that significantly more data are required on CFBC oxy-firing using a much wider range of biomass and coal types. K doping was also examined and did not result in significant formation of K phases on deposit probes
A highly sensitive bio-barcode immunoassay for multi-residue detection of organophosphate pesticides based on fluorescence anti-quenching
Balancing the risks and benefits of organophosphate pesticides (OPs) on human and environmental health relies partly on their accurate measurement. A highly sensitive fluorescence anti-quenching multi-residue bio-barcode immunoassay was developed to detect OPs (triazophos, parathion, and chlorpyrifos) in apples, turnips, cabbages, and rice. Gold nanoparticles were functionalized with monoclonal antibodies against the tested OPs. DNA oligonucleotides were complementarily hybridized with an RNA fluorescent label for signal amplification. The detection signals were generated by DNA-RNA hybridization and ribonuclease H dissociation of the fluorophore. The resulting fluorescence signal enables multiplexed quantification of triazophos, parathion, and chlorpyrifos residues over the concentration range of 0.01–25, 0.01–50, and 0.1–50 ng/mL with limits of detection of 0.014, 0.011, and 0.126 ng/mL, respectively. The mean recovery ranged between 80.3% and 110.8% with relative standard deviations of 7.3%–17.6%, which correlate well with results obtained by LC-MS/MS. The proposed bio-barcode immunoassay is stable, reproducible and reliable, and is able to detect low residual levels of multi-residue OPs in agricultural products.This work was supported by the Central Public Interest Scientific Institution Basal Research Fund for the Chinese Academy of Agricultural Sciences (Grant No.: Y2021PT05), National Institute of Environmental Health Science Superfund Research Program (Grant No.: P42 ES004699), National Academy of Sciences (Subaward No.: 2000009144), and Ningbo Innovation Project for Agro-Products Quality and Safety (Grant No.: 2019CXGC007).Peer reviewe
14-3-3ζ Interacts with Stat3 and Regulates Its Constitutive Activation in Multiple Myeloma Cells
The 14-3-3 proteins are a family of regulatory signaling molecules that interact with other proteins in a phosphorylation-dependent manner and function as adapter or scaffold proteins in signal transduction pathways. One family member, 14-3-3ζ, is believed to function in cell signaling, cycle control, and apoptotic death. A systematic proteomic analysis done in our laboratory has identified signal transducers and activators of transcription 3 (Stat3) as a novel 14-3-3ζ interacting protein. Following our initial finding, in this study, we provide evidence that 14-3-3ζ interacts physically with Stat3. We further demonstrate that phosphorylation of Stat3 at Ser727 is vital for 14-3-3ζ interaction and mutation of Ser727 to Alanine abolished 14-3-3ζ/Stat3 association. Inhibition of 14-3-3ζ protein expression in U266 cells inhibited Stat3 Ser727 phosphorylation and nuclear translocation, and decreased both Stat3 DNA binding and transcriptional activity. Moreover, 14-3-3ζ is involved in the regulation of protein kinase C (PKC) activity and 14-3-3ζ binding to Stat3 protects Ser727 dephosphorylation from protein phosphatase 2A (PP2A). Taken together, our findings support the model that multiple signaling events impinge on Stat3 and that 14-3-3ζ serves as an essential coordinator for different pathways to regulate Stat3 activation and function in MM cells
Residue and Risk Assessment of Fluopyram in Carrot Tissues
This study describes the variation in residue behavior of fluopyram in soil, carrot root, and carrot leaf samples after the application of fluopyram (41.7% suspension, Bayer) by foliar spray or root irrigation at the standard of 250.00 g active ingredient per hectare (a.i./ha) and double-dose treatment (500.00 g a.i./ha). Fluopyram and its metabolite fluopyram-benzamide were extracted and cleaned up using the QuEChERS method and subsequently quantified with LC-QQQ-MS/MS. The LOD and LOQ of the developed method were in the range of 0.05–2.65 ug/kg and 0.16–8.82 ug/kg, respectively. After root irrigation, the final residues detected in edible parts were 0.60 and 1.80 mg/kg, respectively, when 250.00 and 500.00 g a.i./ha were applied, which is much higher than the maximum residue limit in China (0.40 mg/kg). In contrast, after spray application, most of the fluopyram dissipated from the surface of carrot leaves, and the final residues in carrot roots were both only 0.05 mg/kg. Dietary risk assessments revealed a 23–40% risk quotient for the root irrigation method, which was higher than that for the foliar spray method (8–14%). This is the first report comparing the residue behavior of fluopyram applied by root irrigation and foliar spray. This study demonstrates the difference in risk associated with the two application methods and can serve as a reference for the safe application of fluopyram
Reuse of Partially Sulphated CFBC Ash as an SO2 Sorbent
shes produced from fluidized bed combustors (FBC) burning high-sulphur fuels often
contain 20 – 30 % unreacted CaO because of the limestone added to remove SO2 in situ.
This paper presents the results from experiments into reactivating partially sulphated
FBC ash (both bed ash and fly ash) with liquid water, steam and sodium carbonate. The
water- or steam-hydrated ashes were subsequently re-sulphated in a thermogravimetric
analyzer (TGA) with simulated flue gas. The TGA results show that, while liquid water
and steam successfully hydrate and reactivate the unreacted CaO in the bed ash, the
treated ashes sulphated to widely different extents. Attempts to reactivate fly ash with
hydration failed, although fly ash by itself is extremely reactive. A pilot-scale minicirculating
FBC (CFBC) was also used to evaluate the results of reactivation on the bed
ash by hydrating with liquid water and admixtures of inorganic salt (Na2CO3) in the
form of either powder or solution. When the treated ash was re-injected into the
combustor with the fuel, the effect on SO2 removal efficiency was negligible if Na2CO3
was added as powder. Doping with aqueous solution resulted in enhanced SO2 removal;
however, the extent was lower than the level achieved if only water hydration was
employed. Increasing the amount of water (from 10 % to 30 %) to reactivate the ash did
not improve the sulphur capture capacity in the mini-CFBC. Overall, this study
suggests that the most practical way for re-use of the partially sulphated bed ash as a
sulphur sorbent is reactivation by water. A proposal for utilization of the fly ash in an
economically reasonable way is also discussed
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Production of a Monoclonal Antibody for the Detection of Forchlorfenuron: Application in an Indirect Enzyme-Linked Immunosorbent Assay and Immunochromatographic Strip
In this study, a monoclonal antibody (mAb) specific to forchlorfenuron (CPPU) with high sensitivity and specificity was produced and designated (9G9). To detect CPPU in cucumber samples, an indirect enzyme-linked immunosorbent assay (ic-ELISA) and a colloidal gold nanobead immunochromatographic test strip (CGN-ICTS) were established using 9G9. The half-maximal inhibitory concentration (IC50) and the LOD for the developed ic-ELISA were determined to be 0.19 ng/mL and 0.04 ng/mL in the sample dilution buffer, respectively. The results indicate that the sensitivity of the antibodies prepared in this study (9G9 mAb) was higher than those reported in the previous literature. On the other hand, in order to achieve rapid and accurate detection of CPPU, CGN-ICTS is indispensable. The IC50 and the LOD for the CGN-ICTS were determined to be 27 ng/mL and 6.1 ng/mL. The average recoveries of the CGN-ICTS ranged from 68 to 82%. The CGN-ICTS and ic-ELISA quantitative results were all confirmed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) with 84-92% recoveries, which indicated the methods developed herein are appropriate for detecting CPPU in cucumber. The CGN-ICTS method is capable of both qualitative and semiquantitative analysis of CPPU, which makes it a suitable alternative complex instrument method for on-site detection of CPPU in cucumber samples since it does not require specialized equipment