Dioxins and furans releases in Iranian mineral industries.

In this project, emissions of Poly-Chlorinated Dibenzo-p-Dioxins and Dibenzo-Furans (PCDD/Fs) were investigated and estimated for selected Iranian mining and ore processing industries, such as integrated iron & steel plant, primary production of aluminium and copper metal, and the production of cement. As a first step of this study the annual emission of PCDD/Fs was estimated at 120gTEQannum(-1) on the base of the UNEP standardised Toolkit for identification and quantification of dioxin and furan releases. Steel and cement were identified as major emission sources and earmarked for further scrutiny. For that reason, filter dust arising in these plants was sampled and analysed, as well as all raw materials employed. After extraction and clean-up according to standard methods, the resulting liquid samples were analysed and quantified by HRGC-HRMS. Complementary analyses using methods such as XRF, TGA/DTA were performed and the emission results statistically evaluated, in order to put PCDD/F emissions in perspective. It is concluded that the dioxins load of cement dust is unusually low, following the low carbon in raw materials, the use of natural gas as a fuel and the absence of waste incineration. Also the production of iron by direct reduction of ore is a low dioxins process; dioxin loads in dust are as usual - correlated with the presence of catalytic metals. Loss on ignition and chlorine are anti-correlated with the main earth elements and with sulphur oxides.

Effects of overexpression of endogenous phenylalanine ammonia-lyase (PALrs1) on accumulation of salidroside in Rhodiola sachalinensis.

Salidroside, a novel effective adaptogenic drug extracted from the medicinal plant Rhodiola sachalinensis A. Bor, can be derived from phenylalanine or tyrosine. Due to the scarcity of R. sachalinensis and its low yield of salidroside, there is great interest in enhancing production of salidroside by the plant. In this study, a cDNA clone encoding phenylalanine ammonia-lyase (PAL) was isolated from R. sachalinensis using rapid amplification of cDNA ends. The resulting cDNA was designated PALrs1. It is 2407-bp long and encodes 710 deduced amino acid residues. Southern blot analysis of genomic DNA indicated that the PAL gene family is composed of three to five genes in the R. sachalinensis genome. Northern blot analysis revealed that transcripts of PALrs1 were present in calli, leaves and stems, but expression in roots was very low. The PALrs1 under the 35S promoter with double-enhancer sequences from CaMV-Omega and TMV-Omega fragments was transferred into R. sachalinensis via Agrobacterium tumefaciens. PCR and PCR-Southern blot confirmed that the PALrs1 gene had been integrated into the genome of transgenic plants. Northern blot analysis revealed that the PALrs1 gene had been expressed at the transcriptional level. High-performance liquid chromatography indicated that overexpression of the PALrs1 gene resulted in a 3.3-fold increase in p-coumaric acid content, as expected. In contrast, levels of tyrosol and salidroside were 4.7-fold and 7.7-fold, respectively, lower in PALrs1 transgenic plants than in controls. Furthermore, overexpression of the PALrs1 gene resulted in a 2.6-fold decrease in tyrosine content. These data suggest that overexpression of the PALrs1 gene and accumulation of p-coumaric acid did not facilitate tyrosol biosynthesis; tyrosol, as a phenylethanoid derivative, is not derived from phenylalanine; and reduced availability of tyrosine most likely resulted in a large reduction in tyrosol biosynthesis and accumulation of salidroside.

Degradation of PCDD/Fs by mechanochemical treatment of fly ash from medical waste incineration.

The potential of mechanochemical treatment (MC) to degrade PCDD/Fs contained in fly ash was tested via grounding with and without calcium oxide (CaO) under atmospheric pressure. Three types of fly ash collected from medical waste incineration were compared, originating either from rotary kiln fluidized bed multi-stage incinerator using activated carbon spray (FA1, FA2), or a simple stoker incinerator without activated carbon spray (FA3). In test I: CaO to FA1 mixed at ratio of 6-60% was milled at rotational speed of 350 rpm; in test II: FA2 and FA3 without CaO were milled at rotational speed of 400 rpm. The duration of the tests was 2h. The results from the present study indicate that (1) under two test conditions of with and without CaO, PCDD/Fs contained in real fly ash both can be degraded by mechanochemical treatment, (2) under condition of blending with CaO, the degradation efficiency of PCDD/Fs increased with increasing ratio of CaO, (3) the degradation efficiency of PCDD/Fs may increase with rotational speed increasing and (4) the destruction and dechlorination are major mechanism for PCDD/Fs degradation. These results show that mechanochemical treatment is a high potential technology for PCDD/Fs degradation in fly ash.

YY1 represses rat serum amyloid A1 gene transcription and is antagonized by NF-kappa B during acute-phase response.

Serum amyloid A (SAA), one of the major acute-phase proteins, increases several hundredfold in concentration in plasma following acute inflammation, primarily as a result of a 200-fold increase in its transcriptional rate. Functional analysis of the rat SAA1 promoter has identified a 65-bp cytokine response unit (CRU; positions -135 to -71) that could confer cytokine responsiveness on a heterologous promoter. Within this CRU, two cis-regulatory elements, corresponding to NF-kappa B- and C/EBP-binding sites, were found to be functionally important and exerted synergistic effects on induced SAA1 expression. In this report, we show that a third transcription factor interacts with the CRU through a region located between the NF-kappa B- and C/EBP-binding sites. On the basis of its gel mobility shift patterns, ubiquitous binding activity, sequence specificity of DNA binding, zinc-dependent binding activity, and gel mobility supershift by specific antibodies, we concluded that this factor is identical to YY1. Methylation interference studies revealed that YY1 binding sequences overlapped with those of NF-kappa B, and gel mobility studies showed that NF-kappa binding to the CRU was effectively inhibited by YY1. Consistent with its presumed antagonistic role to NF-kappa B, YY1 exerted a negative effect on SAA1 expression, whereas disruption of its binding in the promoter elevated basal and cytokine-induced activities. Furthermore, overexpression of YY1 trans-repressed SAA1 promoter activity. Thus, our results demonstrate that SAA1 expression is tightly regulated by an on-off switch of activators and repressors, presumably to ensure that it is expressed only under appropriate physiological conditions.