Interaction of heavy metals and pyrene on their fates in soil and tall fescue (Festuca arundinacea).

90-Day growth chamber experiments were performed to investigate the interactive effect of pyrene and heavy metals (Cu, Cd, and Pb) on the growth of tall fescue and its uptake, accumulation, and dissipation of heavy metals and pyrene. Results show that plant growth and phytomass production were impacted by the interaction of heavy metals and pyrene. They were significantly decreased with heavy metal additions (100-2000 mg/kg), but they were only slightly declined with pyrene spiked up to 100 mg/kg. The addition of a moderate dosage of pyrene (100 mg/kg) lessened heavy metal toxicity to plants, resulting in enhanced plant growth and increased metal accumulation in plant tissues, thus improving heavy metal removal by plants. In contrast, heavy metals always reduced both plant growth and pyrene dissipation in soils. The chemical forms of Cu, Cd, and Pb in plant organs varied with metal species and pyrene addition. The dissipation and mineralization of pyrene tended to decline in both planted soil and unplanted soils with the presence of heavy metals, whereas they were enhanced with planting. The results demonstrate the complex interactive effects of organic pollutants and heavy metals on phytoremediation in soils. It can be concluded that, to a certain extent, tall fescue may be useful for phytoremediation of pyrene-heavy metal-contaminated sites. Further work is needed to enhance methods for phytoremediation of heavy metal-organics co-contaminated soil.

Effect of ATF3-deletion on apoptosis of cultured retinal ganglion cells.

AIM: To investigate the effect of activating transcription factor-3 (ATF3)-deletion on apoptosis of cultured retinal ganglion cells (RGCs). METHODS: Three ATF3 siRNA (ATF3-rat-651, ATF3-rat-319, ATF3-rat-520) were constructed, and were transiently transfected into RGC-5 cells. Quantitative real-time polymerase chain reaction (PCR) was used to examine ATF3 expression and the most effective ATF3 siRNA was selected for further studies. Flow cytometry was applied to investigate the effects of ATF3 deletion on RGC-5 apoptosis under elevated hydrostatic pressure. Quantitative real-time PCR and Western blot were performed to validate differentially expressed genes and proteins in ATF3-knockdown RGC-5 cells. RESULTS: ATF3 specific siRNA effectively down-regulated ATF3 expression and significantly inhibited cell apoptosis in RGC-5 cells. Quantitative real-time PCR and Western blot confirmed that ATF3 knockdown remarkably decreased Jun-B and increased c-Jun at both mRNA and protein levels in RGC-5 cells. CONCLUSION: ATF/cAMP-response element-binding family of transcription factors may be involved in the development of glaucoma and could be novel treatment targets for glaucoma.

Inhibition on Apoptosis Induced by Elevated Hydrostatic Pressure in Retinal Ganglion Cell-5 via Laminin Upregulating ß1-integrin/Focal Adhesion Kinase/Protein Kinase B Signaling Pathway.

BACKGROUND: Glaucoma is a progressive optic neuropathy characterized by degeneration of neurons due to loss of retinal ganglion cells (RGCs). High intraocular pressure (HIOP), the main risk factor, causes the optic nerve damage. However, the precise mechanism of HIOP-induced RGC death is not yet completely understood. This study was conducted to determine apoptosis of RGC-5 cells induced by elevated hydrostatic pressures, explore whether laminin is associated with apoptosis under pressure, whether laminin can protect RGCs from apoptosis and affirm the mechanism that regulates the process of RGCs survival. METHODS: RGC-5 cells were exposed to 0, 20, 40, and 60 mmHg in a pressurized incubator for 6, 12, and 24 h, respectively. The effect of elevated hydrostatic pressure on RGC-5 cells was measured by Annexin V-fluorescein isothiocyanate/propidium iodide staining, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and Western blotting of cleaved caspase-3 protein. Location and expression of laminin were detected by immunofluorescence. The expression of ß1-integrin, phosphorylation of focal adhesion kinase (FAK) and protein kinase B (PKB, or AKT) were investigated with real-time polymerase chain reaction and Western blotting analysis. RESULTS: Elevated hydrostatic pressure induced apoptosis in cultured RGC-5 cells. Pressure with 40 mmHg for 24 h induced a maximum apoptosis. Laminin was declined in RGC-5 cells after exposing to 40 mmHg for 24 h. After pretreating with laminin, RGC-5 cells survived from elevated pressure. Furthermore, ß1-integrin and phosphorylation of FAK and AKT were increased compared to 40 mmHg group. CONCLUSIONS: The data show apoptosis tendency of RGC-5 cells with elevated hydrostatic pressure. Laminin can protect RGC-5 cells against high pressure via ß1-integrin/FAK/AKT signaling pathway. These results suggest that the decreased laminin of RGC-5 cells might be responsible for apoptosis induced by elevated hydrostatic pressure, and laminin or activating ß1-integrin/FAK/AKT pathway might be potential treatments to prevent RGC loss in glaucomatous optic neuropathy.

Beneficial effect of farnesoid X receptor activation on metabolism in a diabetic rat model.

Farnesoid X receptor (FXR) is an important regulator of glucose and lipid homeostasis. However, the exact role of FXR in diabetes remains to be fully elucidated. The present study examined the effects of chenodeoxycholic acid (CDCA), an agonist of FXR, on metabolism profile in a rat model of type 2 diabetes mellitus (T2DM). Male Wistar rats (8­week­old; n=40) were randomized into the following four groups (n=10): Untreated control, CDCA­treated, T2DM, and CDCA­treated T2DM. To establish the T2DM model, the rats were fed a high­fat diet (HFD) for 4 weeks and received a single low­dose intraperitoneal injection of streptozotocin (30 mg/kg), followed by an additional 4 weeks of HFD feeding. CDCA was administrated (10 mg/kg/d) intraperitoneally for 10 days. Reverse transcription­quantitative polymerase chain reaction and western blotting assays were performed to determine the RNA and protein expression of FXR, phosphoenolpyruvate carboxykinase, G6Pase, proliferator­activated receptor­Î³ coactivator­1 and short heterodimer partner in rat liver tissue. The results revealed that FXR activation by CDCA did not reduce body weight, but it lowered the plasma levels of fasting glucose, insulin and triglycerides in the T2DM rats. CDCA administration reversed the downregulation of the mRNA and protein expression of FXR in the T2DM rat liver tissue samples. Furthermore, treatment with CDCA reduced the mRNA and protein expression levels of phosphoenolpyruvate carboxykinase, glucose 6­phosphatase and peroxisome proliferator­activated receptor­Î³ coactivator­1 in the liver tissue samples of the T2DM rats. By contrast, CDCA treatment increased the mRNA and protein expression levels of short heterodimer partner in the liver tissue samples of the T2DM rats. In conclusion, FXR agonist treatment induces beneficial effects on metabolism in the rat T2DM model. In conclusion, the present study indicated that the FXR agonist may be useful for the treatment of T2DM and hypertriglyceridemia.

Clinical value of self-assessment risk of osteoporosis in Chinese.

BACKGROUND: Early detection of high-risk population for osteoporosis is the key to preventing this disease. METHODOLOGY: In this cross-sectional study a continuous sample of 270 women and 89 men (age: 20-90 years) was divided into four groups by age (≤ 55 or > 55 years) and sex. Participants completed the IOF test. Low-, medium-, and high-risk grades were defined by an OSTA index of greater than -1, -1 to -4, and less than -4, respectively. RESULTS: Most participants were categorized in the low-risk group (240 people, 66.9%), followed by the medium-risk (102 people, 28.4%) and high-risk groups (17 people, 4.7%). Compared to women, men in both age groups had significantly higher OSTA index and greater numbers of positive answers on the IOF test. 64.3% individuals were susceptible to osteoporosis risk (≥1 positive answers on the IOF test). Multiple regression analysis demonstrated that family history of fragility fracture (OR: 0.503, 95% CI: 0.26-0.97), height loss exceeding 3 cm (OR: 2.51, 95% CI: 1.55-4.05), and earlier menopause (OR: 0.434, 95% CI: 0.19-0.97) were associated with higher risk grades. CONCLUSIONS: Combined use of the OSTA and IOF test is a simple and effective method for assessing the risk of osteoporosis.

Analysis of bacterial diversity in two oil blocks from two low-permeability reservoirs with high salinities.

The community diversities of two oil reservoirs with low permeability of 1.81 × 10(-3) and 2.29 × 10(-3) µm(2) in Changqing, China, were investigated using a high throughput sequencing technique to analyze the influence of biostimulation with a nutrient activator on the bacterial communities. These two blocks differed significantly in salinity (average 17,500 vs 40,900 mg/L). A core simulation test was used to evaluate the effectiveness of indigenous microbial-enhanced oil recovery (MEOR). The results indicated that in the two high salinity oil reservoirs, one reservoir having relatively lower salinity level and a narrow salinity range had higher bacterial and phylogenetic diversity. The addition of the nutrient activator increased the diversity of the bacterial community structure and the diversity differences between the two blocks. The results of the core simulation test showed that the bacterial community in the reservoir with a salinity level of 17,500 mg/L did not show significant higher MEOR efficiency compared with the reservoir with 40,900 mg/L i.e. MEOR efficiency of 8.12% vs 6.56% (test p = 0.291 > 0.05). Therefore, salinity levels affected the bacterial diversities in the two low permeability oil blocks remarkably. But the influence of salinity for the MEOR recovery was slightly.

Isolation and characterization of a crude oil degrading bacteria from formation water: comparative genomic analysis of environmental Ochrobactrum intermedium isolate versus clinical strains.

In this study, we isolated an environmental clone of Ochrobactrum intermedium, strain 2745-2, from the formation water of Changqing oilfield in Shanxi, China, which can degrade crude oil. Strain 2745-2 is aerobic and rod-shaped with optimum growth at 42 °C and pH 5.5. We sequenced the genome and found a single chromosome of 4 800 175 bp, with a G+C content of 57.63%. Sixty RNAs and 4737 protein-coding genes were identified: many of the genes are responsible for the degradation, emulsification, and metabolizing of crude oil. A comparative genomic analysis with related clinical strains (M86, 229E, and LMG3301(T)) showed that genes involved in virulence, disease, defense, phages, prophages, transposable elements, plasmids, and antibiotic resistance are also present in strain 2745-2.

Biodegradation of decabromodiphenyl ether (BDE-209) by a metal resistant strain, Bacillus cereus JP12.

A metal resistant bacterial strain, Bacillus cereus JP12, could use decabromodiphenyl ether (BDE-209) as the sole carbon and energy source for growth in mineral salt medium. Under the conditions of pH 6.0, 30°C, 150 rpm and an inoculum of OD600=0.6, more than 88% of the initial BDE-209 (1mg/L) was degraded after 12 days. The addition of appropriate surfactants and additional carbon sources could enhance the biodegradation efficiency of BDE-209. The presence of Cu(2+) (≤ 8 mg/L) and Zn(2+) (≤ 15 mg/L) provided a slight stimulating effect on BDE-209 removal. However, BDE-209 biodegradation efficiency was decreased when adding higher levels of metals due to reduced substrate availability caused by excess metal adsorption into the cell surface. Biosorption of heavy metals by JP12 led to release of light metals such as K(+) and Na(+). A BDE-209 biodegradation pathway was proposed on the basis of metabolite identification.

Effect of copper on in vivo fate of BDE-209 in pumpkin.

A 60-day growth chamber experiments were performed to investigate the effect of Cu stress on the uptake, translocation and metabolism of decabromodiphenyl ether (BDE-209) by pumpkin. A total of nine debrominated metabolites (de-PBDEs), two hydroxylated PBDEs (OH-PBDEs) and one methoxylated PBDEs (MeO-PBDEs) were detected in the tested plants. Concentrations of the total debrominated, hydroxylated or methoxylated metabolites generally followed the order of roots>stems>leaves, and de-PBDEs>OH-PBDEs>MeO-PBDEs. These results indicate that metabolism occurred preferentially in roots than in stems and leaves. The addition of moderate dosage of Cu (50mg/kg) resulted in increment in OH-PBDE concentrations in plant tissues, whereas higher concentrations of Cu could inhibit uptake and metabolism of BDE-209. No in vivo mineralization of BDE-209 was detected in the plants. These results provide valuable information about the behavior of BDE-209 in plant tissues under heavy metal exposure.

Bacterial community diversity in a low-permeability oil reservoir and its potential for enhancing oil recovery.

The diversity of indigenous bacterial community and the functional species in the water samples from three production wells of a low permeability oil reservoir was investigated by high-throughput sequencing technology. The potential of application of indigenous bacteria for enhancing oil recovery was evaluated by examination of the effect of bacterial stimulation on the formation water-oil-rock surface interactions and micromodel test. The results showed that production well 88-122 had the most diverse bacterial community and functional species. The broth of indigenous bacteria stimulated by an organic nutrient activator at aerobic condition changed the wettability of the rock surface from oil-wet to water-wet. Micromodel test results showed that flooding using stimulated indigenous bacteria following water flooding improved oil recovery by 6.9% and 7.7% in fractured and unfractured micromodels, respectively. Therefore, the zone of low permeability reservoir has a great potential for indigenous microbial enhanced oil recovery.

Dechlorination of short chain chlorinated paraffins by nanoscale zero-valent iron.

In this study, nanoscale zero-valent iron (NZVI) particles were synthesized and used for the reductive dehalogenation of short chain chlorinated paraffins (SCCPs) in the laboratory. The results show that the dechlorination rate of chlorinated n-decane (CP(10)) by NZVI increased with decreased solution pH. Increasing the loading of NZVI enhanced the dechlorination rate of CP(10). With an increase in temperature, the degradation rate increased. The reduction of CP(10) by NZVI was accelerated with increasing the concentration of humic acid up to 15 mg/L but then was inhibited. The dechlorination of CP(10) within the initial 18 h followed pseudo-first order rate model. The formation of intermediate products indicates a stepwise dechlorination pathway of SCCPs by NZVI. The carbon chain length and chlorination degree of SCCPs have a polynominal impact on dechlorination reactions.

Oil recovery from refinery oily sludge using a rhamnolipid biosurfactant-producing Pseudomonas.

In this study, a rhamnolipid biosurfactant-producing strain, Pseudomonas aeruginosa F-2, was used to recover oil from refinery oily sludge in laboratory and pilot-scale experiments. The optimum values of carbon to nitrogen ratio, temperature, sludge-water ratio and inoculum size for oil recovery were determined as 10, 35 °C, 1:4 and 4%, respectively. An oil recovery of up to 91.5% was obtained with the equipping of draft tubes during the field pilot-scale studies. The results showed that strain F-2 has the potential for industrial applications and may be used in oil recovery from oily sludge.

Evaluation of PCDD/Fs emissions during ceramic production: a laboratory study.

Because of the ubiquity of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in kaolinitic clays, the ceramic industry is considered to be a potential source of PCDD/Fs. However, studies on the emission of PCDD/Fs from ceramic production are still very scarce. In this study, PCDD/Fs emissions during ceramic production were investigated in an electric laboratory batch kiln. The results showed that the PCDD/Fs were completely removed from the ceramic pieces after 30 min of firing at the peak temperature of 1200°C. Nevertheless, on the mass and international toxic equivalent basis, 27.5% and 46.2% of the total PCDD/Fs amount in the raw clay were released into the atmosphere during firing, respectively. These PCDD/Fs were emitted into the air before the temperature was elevated to a level high enough for their destruction. Dechlorination reactions generated a broad distribution within the PCDD/Fs congeners including a variety of non-2,3,7,8-substituted ones. The emission of PCDD/Fs was decreased to 16.3 wt.% of the total PCDD/Fs amount in the raw clay, when the initial kiln temperature was enhanced to 600°C. The emission of PCDD/Fs could be reduced significantly in the presence of a glaze coating on the ceramic test piece. These results indicated that ceramic production is an un-neglectable source of PCDD/Fs in the environment.

Effect of microbial treatment on the prevention and removal of paraffin deposits on stainless steel surfaces.

In this study, biosurfactant-producing strain N2 and non-biosurfactant producing stain KB18 were used to investigate the effects of microbial treatment on the prevention and removal of paraffin deposits on stainless steel surfaces. Strain N2, with a biosurfactant production capacity, reduced the contact angle of stainless steel to 40.04°, and the corresponding adhesion work of aqueous phase was decreased by 26.5 mJ/m(2). By contrast, KB18 could only reduce the contact angle to 50.83°, with a corresponding 7.6 mJ/m(2) decrease in the aqueous phase work adhesion. The paraffin removal test showed that the paraffin removal efficiencies of strain N2 and KB18 were 79.0% and 61.2%, respectively. Interestingly, the N2 cells could attach on the surface of the oil droplets to inhibit droplets coalescence. These results indicate that biosurfactant-producing strains can alter the wettability of stainless steel and thus eliminate paraffin deposition.

[Characteristic of sludge thermal hydrolysis using microwave heating with alkali addition].

NaOH was added into sludge to improve thermal hydrolysis when heated with microwave irradiation. Volatile suspended solid (VSS) rapidly dissolved into aqueous phase when adding 0.1 g NaOH per gram into suspended solid (SS) of sludge. More than 60% of VSS solubilized at 170 degrees C, and VSS to SS ratio of treated sludge reduced to 25%. For 5 min treatment, soluble COD (SCOD) in treated sludge liquid phase was 9.8, 12.8, 15.1, and 14.5 g/L respectively at 80, 120, 150 and 170 degrees C. Accordingly, the SCOD to TCOD (total COD) ratio was 24.0%, 31.3%, 36.9% and 35.6%. The pH of the microwave heated sludge decreased with higher temperature and longer hydrolysis time, while the finale pH of different testes were still higher than 10.5. Alkali dose effect on organic matters dissolving was analyzed at the range of 0-0.2 g NaOH into per gram SS. Results showed that when alkali dose was above 0.05 g, the rapid dissolving trend became level for VSS and SS. BMP (biochemical methane potential) test was used to investigate treated sludge digestibility at NaOH dose of 0.05 g with 5 min microwave heating at set temperature and 0.1 g with 1 min heating. Results showed that adding 0.05 g NaOH improved sludge anaerobic digestion, the biogas production was 28.5% higher than control at 150 degrees 2, while adding 0.1 g NaOH would inhibit treated sludge digestion process.

[Rhizosphere enhanced remediation of petroleum contaminated soil].

The effects of growing tall fescue on the biodegradation of hydrocarbons was studied in laboratory scale pots. Degradation of hydrocarbons as well as microbial counts, soil fluorescein diacetate activity, catalase activity and dehydrogenase activity were determined. The results showed that, in the rhizosphere soil system, total petroleum hydrocarbons disappeared faster than that in unvegetated pots soil. After 10 weeks, 11.8% and 27.4% of spiked petroleum hydrocarbons disappeared from the bulk and rhizosphere soils respectively. Abiotic loss of petroleum hydrocarbons by evaporation was of minor significance in the test. The microbial plate counts and soil enzyme activities were significantly higher in the rhizosphere than in the bulk soil. Petroleum compounds had significant effect on fluorescein diacetate hydrolyzing activity. Vegetation resulted in significantly greater first-order decay constants compared to the unvegetated control. Oxygenated polycyclic aromatic hydrocarbons that were present in the soil were generally degraded more slowly than the parent compounds, suggesting that they were formed during the treatment or that they are more persistent. Four oxidation products of polycyclic aromatic hydrocarbons, 1-acenaphthenone, 9-fluorenone, anthraquinone, and benzfluorenone were found at significantly higher concentrations at the end of the study.