[Risk Assessment and Source Analysis of Heavy Metals in the River of a Typical Bay Watershed].

Based on the survey data of eight kinds of heavy metals in the Xiangshan Bay watershed during the flood season, the pollution status of heavy metals in water was analyzed. The potential ecological risks of heavy metals were evaluated based on the single factor pollution index (Pi), the Nemero comprehensive pollution index (Pn), and the heavy metal pollution index (HPI). Based on the correlation between land-use types and heavy metal concentrations, the sources of heavy metals were analyzed. The results show that the average concentration of heavy metals is in the order Fe > Mn > Zn > Cu > As > Cr > Pb > Cd. All heavy metal concentrations, except those of Mn and Fe, conform to the class I surface water environment quality standard. The risk level of heavy metals is low, and there is no pollution, but some contamination. Agricultural non-point source pollution is the main factor in the contamination of heavy metals. Overall, the heavy metals in the region have not reached the risk threshold. To reasonably avoid the risk of heavy metal pollution in the urban development process, it is important to strengthen the supervision of pollution sources based on agricultural non-point sources.

Antibacterial and anti-biofilm activity of the lipid extract from Mantidis ootheca on Pseudomonas aeruginosa.

The aim of this study is to assess the antibacterial and anti-biofilm properties of the lipid extract from Mantidis ootheca against the gentamycin resistant Pseudomonas aeruginosa. The chemical composition of the lipid extract and its relative proportion were determined using the technique of gas chromatography coupled with mass spectrometry (GC-MS). Antibacterial susceptibility tests were performed using a disc diffusion assay and the minimum inhibition concentration (MIC) was determined by way of the agar dilution method. The anti-biofilm test was carried out with crystal violet staining and scanning electron microscopy (SEM). There were 16 compounds detected, and the most abundant components were sesquiterpenoids, monoterpenes, and trace aromatic compounds. The MIC for P. aeruginosa was 4 mg/ml and the eradication effect on preformed biofilms was established and compared with a ciprofloxacin control. The results of our study indicated that a lipid extract from M. ootheca could be used as a topical and antibacterial agent with anti-biofilm activity in the future.

Effectiveness of omega-3 polyunsaturated fatty acids against microbial pathogens.

Microorganisms provide both beneficial and harmful effects to human beings. Beneficial effects come from the symbiotic relationship that exists between humans and microbiota, but then several human illnesses have turned some friendly microbes into opportunistic pathogens, causing several microbial-related diseases. Various efforts have been made to create and utilize antimicrobial agents in the treatment and prevention of these infections, but such efforts have been hampered by the emergence of antimicrobial resistance. Despite extensive studies on drug discovery to alleviate this problem, issues with the toxicity and tolerance of certain compounds and continuous microbial evolution have forced researchers to focus on screening various phytochemical dietary compounds for antimicrobial activity. Linolenic acid and its derivatives (eicosapentaenoic acid and docosahexaenoic acid) are omega-3 fatty acids that have been studied due to their role in human health, being important for the brain, the eye, the cardiovascular system, and general human growth. However, their utilization as antimicrobial agents has not been widely appreciated, perhaps due to a lack of understanding of antimicrobial mechanisms, toxicity, and route of administration. Therefore, this review focuses on the efficacy, mechanism, and toxicity of omega-3 fatty acids as alternative therapeutic agents for treating and preventing diseases associated with pathogenic microorganisms.

Melatonin attenuates lung ischaemia-reperfusion injury via inhibition of oxidative stress and inflammation.

OBJECTIVES: Lung ischaemia-reperfusion injury is a complex pathophysiological process due to the production of reactive oxygen species and the generation of inflammatory reaction. We investigated the protective effects and the corresponding mechanism of melatonin (MT), a potent free-radical scavenger, on lung injury induced by ischaemia-reperfusion in a mouse model. METHODS: Adult male C57BL/6J mice (n = 30) were randomly and equally allocated into 5 groups: sham controls, IR, IR + 10 mg/kg MT, IR + 20 mg/kg MT and IR + 30 mg/kg MT. Lung ischaemia-reperfusion injury was induced by thoracotomy followed by clamping of the left hilum for 1 h and subsequent reperfusion for 2 h. RESULTS: Histological scoring analysis showed that lung parenchymal damage was ameliorated in the melatonin pretreatment groups when compared with the IR group, with the IR + 20 mg/kg MT group showing the strongest effect among the melatonin pretreatment groups. Wet-to-dry weight ratio, detection of malondialdehyde, protein expressions of inflammatory factors (tumour necrosis factor-α, interleukin-1ß, NF-κB and IKK-γ) and apoptotic factors (cleaved caspase-3 and Bax/Bcl-2), as well as TUNEL assay showed changes similar to those of the lung injury scores in all groups. In contrast, the examination of superoxide dismutase showed a pattern contrary to that of the lung injury score in all groups. In addition, immunohistochemistry staining showed that the expressions of the antioxidants glutathione peroxidase and glutathione reductase were increased in the melatonin pretreatment groups. CONCLUSIONS: This study demonstrated that melatonin pretreatment attenuated lung ischaemia-reperfusion injury via inhibition of oxidative stress, inflammation and apoptosis.

Expression of glucose transporter-1, hypoxia inducible factor-1α and beclin-1 in head and neck cancer and their implication.

Previous studies have demonstrated that oncogenes, tumor suppressor genes, and hypoxic factors are involved in the pathogenesis, development, and progression of head and neck cancer. In this study, we investigated the expression of HIF-1α, GLUT-1, and beclin-1 in head and neck cancers and analyzed the relationship between these markers and clinicopathologic factors. 44 paraffin-embedded samples of head and neck cancer specimens were collected. The expression of HIF-1α, GLUT-1, Ki 67, and beclin-1 was detected by immunohistochemical technique. The expression of HIF-1α, GLUT-1, Ki 67, and beclin-1 in head and neck cancers were higher than those for the corresponding paracancerous tissues. Stratification analysis revealed a significant difference between GLUT-1 expression in older patients with laryngeal/hypopharyngeal SCC and younger patients with laryngeal/hypopharyngeal SCC. No significant differences in GLUT-1 or beclin-1 or HIF-1α or Ki 67 expression were found between clinicopathologic characteristics, including lymph node metastasis, T stage, clinical stage, and location, for any of the cancer types studied. Pearson analysis revealed that there was a negative correlation between beclin-1 and HIF-1α (r=0.482, P=0.001), and between beclin-1 and Ki-67 (r=-0.366, P=0.0151). Whether beclin-1 plays a role in carcinogenesis in head and neck cancers should be further studied.

TGF-ß signaling regulates DACT1 expression in intestinal epithelial cells.

DACT1, was first identified as a Dishevelled-associated antagonist of Wnt signaling pathway. It has been reported that DACT1 functions in embryonic development and tumorigenesis. However, the regulation of DACT1 still remains unclear. We found Wnt signaling has no effect on DACT1, but TGF-ß increases expression of DACT1 in intestinal epithelial cells. In addition, the minimal promoter is located in the region of -500bp to +1bp and the region between -3000bp to +1bp enhanced promoter activity. Site-directed mutation analysis was performed and indicated that potential regulatory elements was near -335bp. Our study provided the basic information for the exploration of DACT1 regulation and expression. Moreover, TGF-ß inhibits Wnt signaling to enhance the function of DACT1 inhibiting Wnt signaling.

Microbial community analysis of simultaneous ammonium removal and Fe3+ reduction at different influent ammonium concentrations.

This study investigates the impacts of influent ammonium concentrations on the microbial community in immobilized heterotrophic ammonium removal system. Klebsiella sp. FC61, the immobilized species, has the ability to perform simultaneous ammonium removal and Fe3+ reduction. It was found that average ammonium removal rate decreased from 0.308 to 0.157 mg/L/h, as the influent NH4+-N was reduced from 20 to 10 mg/L. Meanwhile, at a total Fe3+ concentration of 20 mg/L, the average Fe3+ reduction removal efficiency and rate decreased from 44.61% and 0.18 mg/L/h, to 27.10% and 0.11 mg/L/h, respectively. High-throughput sequencing was used to observe microbial communities in bioreactor Samples B1, B2, and B3, after exposure to different influent NH4+-N conditions. Results show that higher influent NH4+-N concentrations increased microbial richness and diversity and that Klebsiella sp. FC61 play a functional role in the simultaneous removal of NH4+-N and Fe3+ reduction in bioreactor systems.

ANTITUMOR AND APOPTOTIC EFFECTS OF CUCURBITACIN A IN A-549 LUNG CARCINOMA CELLS IS MEDIATED VIA G2/M CELL CYCLE ARREST AND M-TOR/PI3K/AKT SIGNALLING PATHWAY.

BACKGROUND: The main aim of this study was to demonstrate the antitumor potential of cucurbitacin A on A-549 NSCLC (non-small cell lung cancer cells). The effects of Cucurbitacin A on apoptotic induction, cell physic, cell cycle failure and m-TOR/PI3K/Akt signalling pathway were also investigated in the present study. MATERIALS AND METHODS: MTT assay and clonogenic assay were carried out to study effects of this compound on cell cytotoxicity and colony forming tendency in A-549 cells. Moreover, phase and fluorescence microscopic techniques were used to examine the effects on cell morphology and induction of apoptosis. The effects on cell cycle phase distribution were investigated by flow cytometry and effects on m-TOR/PI3K/Akt signalling proteins were assessed by western blot analysis. RESULTS: Results showed that cucurbitacin A induced dose-dependent cytotoxic effects along with suppressing the colony forming tendency in these cells. Cucurbitacin A also induced morphological changes in these cells featuring chromatin condensation, cell shrinkage and apoptotic body formation. G2/M phase cell cycle collapse was also induced by Cucurbitacin A along with inhibition of expression levels of m-TOR/PI3K/Akt proteins. CONCLUSIONS: In conclusion, cucurbitacin A inhibits cancer growth in A-549 NSCLC cells by inducing apoptosis, targeting m-TOR/PI3K/Akt signalling pathway and G2/M cell cycle.

[Effects of UV Radiation on the Coagulation Process of Kaolin and Involved Mechanisms].

Kaolin commonly exists in water,and it has an important impact on the water treatment processes and contaminants'migration and transformation.In this study,PAC was used as flocculating agent to systematically investigate the effects of UV radiation on the coagulation process of kaolin by jar test.The results showed that under neutral and acidic conditions,UV radiation could promote the coagulation process of kaolin suspension.When the solution pH,coagulant dosage and irradiation time were 7.0,30 mg·L-1 and 2.0 h,respectively,the kaolin remove rate of effluent after coagulation increased from 81.05% to 93.90% by using UV radiation.This might be related to the decrease of-OH stretching vibration absorption peak and the enhancement of Si-O stretching vibration absorption peak and Si-O bending vibration absorption peak after UV radiation,so that the number of the active spot (-OH) on kaolin surface declined.These changes might lead to decrease of the negative charge on kaolin surface,which promoted kaolin suspension to precipitate in coagulation process.However,under alkaline conditions,its settlement performance was slightly lower than the water samples without ultraviolet radiation treatment.

[Effects of UV Radiation on the Physicochemical Properties and Coagulation Properties of Humic Acid Solution].

To investigate the mechanism of UV light in promoting the removal of humic acid ( HA) by coagulation, the variations of the physical and chemical properties of the HA solution before and after UV light radiation were investigated. The effects of the changes in water quality conditions on the removal performance of HA in coagulation were also observed. Experimental results showed that except zeta potential, pH, chromaticity and viscosity of the HA solution exhibited varying degrees of decline after UV radiation. Further study showed that the impact of changes in viscosity of the solution on humic acid coagulation performance was relatively small. Under acidic conditions, the coagulation performance of HA significantly increased. The increase of zeta potential led to easy gathering of colloidal particles and improved the coagulation performance. Furthermore, except for HA with relative molecular mass of between (10-30) x 10³ and less than 10³, there was little variation in the proportion of low molecular weight HA, which may be an important reason that the coagulation performance of the humic acid solution increased after UV radiation.

[Effect of UV Light Radiation on the Coagulation of Chlorella and Its Mechanism].

Considering algae were difficult to be effectively removed in conventional water treatment process, UV radiation was used to enhance the coagulation of algae in this study. The results showed that with the increase of radiation time, the removal rates of both algae and turbidity experienced a decrease after an increase, and reached their maximum values at 50 min. When the dosage of PAC was 5 mg x L(-1), the removal rates of algae and turbidity of the radiated sample were 20.1% and 18% higher than the blank sample, respectively. When pH ranged from 6 to 9, the coagulation efficiency varied little. At pH 8 and with a radiation time of 50 min, the removal rates of algae and turbidity reached 93.5% and 90.6%, respectively. Meanwhile, the Zeta potential reached the maximum, and the algae generated extracellular organic matter, which favored the subsequent coagulation. After radiated for 60 min, the algal cells was destroyed, leading to a release of intracellular organic matter into the solution. Accordingly, the Zeta potential decreased, which had a negative effect on the subsequent coagulation process.

[Preparation and NH4+-N Removal Performance of a Novel Filter Substrate Made from Sludges].

A novel absorbent was prepared by high-temperature calcination using waterworks terminal aluminum coagulation sludge as a raw material. This study discussed ammonia nitrogen adsorption performance of the adsorbent by static adsorption test, mainly investigated the influences of different initial pH, contact time and temperatures on the ammonia adsorption effect, and also analyzed the adsorption isotherms, kinetic and thermodynamic properties of adsorbent on the ammonia nitrogen. Experimental results showed that the adsorbent had a better effect for ammonia removal under neutral conditions; the adsorption process was basically balanced within 6 h, and it followed the pseudo second-order model. Langmuir adsorption model could be better fitted for the adsorption of ammonia adsorbent; the thermodynamic parameters indicated that the adsorption process of ceramic adsorbents on NH4+-N was a kind of spontaneous, endothermic reaction (ΔGθ <0, ΔHθ >0), and it was found to be a physical adsorption based on the average adsorption energy. Thus, treating ammonia wastewater by coagulation sludge has a good prospect.

[Effects of Hydraulic Loading Rate on the Removal of Pollutants from an Integrated Biological Settling Tank].

Based on the designing concepts of rotating biological disk and settling tank, a hybrid biological purification and settling tank was developed to achieve simultaneous removal of turbidity causing materials, organic matters, NH4+-N, and TP. Experimental results showed that under certain rotary speed and water quality conditions, the removal rates of both turbidity and organic matters and NH4+-N were relatively stable first and then started to decrease with the increase of hydraulic loading rate. The highest value was achieved at 0.036 g·(m2·d)-1 and 0.064 g·(m2·d)-1 respectively. Compared with turbidity and TOC and NH4+-N, the removal rate of TP was greatly influenced by hydraulic loading rate. The average TP removal was the worst at 0.064 g·(m2·d)-1. Appropriately decreasing or increasing the hydraulic load was helpful to the phosphorus removal process. Further study showed that nitrification and dephosphorization processes competed for the limited carbon source and DO in the water phase. Along the flow direction, the surface of the disc populations of microorganisms with good coordination and distribution along the characteristics ensured that the process still had certain decontamination effect under the condition of unfavorable hydraulic load, which indicated that the biological settling tank had a capacity in resisting organic loading rate shock and could be used in enhancing pollutant removal in treating micro-polluted water.

[Enhanced Pollutant Removal Performance of an Integrated Biological Settling Tank from Micro-polluted Water Bodies].

To improve the capacity of present drinking water purification process on the removal of soluble pollutants and solve the problem of large area requirement and single function existing in the application of horizontal sedimentation tank, a novel biological settling tank was developed based on the designing concepts of rotating biological disk and sedimentation tank. Experimental results showed that the usage of rotating biological disk did not have notable effects on the turbidity removal capacity of the horizontal sedimentation tank. When the organic loading rate was 0.46 g·(m2·d)-1, the removal rates of organic pollutants, NH4+-N, TN, and TP were determined to be 81.4%, 95.0%, 21.1% and 86.0%, respectively. Further study showed that denitrification and dephosphorization processes competed for the limited carbon source existing in the water phase. With the increase of organic loading rate in the raw water, the removal rate of TP was improved. Meanwhile, the concentrations of organic matters and NH4+-N in the settled water were not affected, which indicated that the biological settling tank showed a capacity in resisting organic loading rate shock and could be used in the enhanced pollutant removal in treating micro-polluted water.

Preparation and application of porous nitrogen-doped graphene obtained by co-pyrolysis of lignosulfonate and graphene oxide.

Nitrogen-doped graphene with in-plane porous structure was fabricated by simple co-pyrolysis of lignosulfonate and graphene oxide in the presence of urea. Lignosulfonate first performs as a dispersant adsorbed on the surface of graphene oxide to prevent the aggregation of graphene oxide sheets for preparing homogeneous nitrogen-containing precursor, and then acts as a porogen to render graphene sheets with nanopores in the pyrolysis process of the nitrogen-containing precursor. Urea was used as a nitrogen source to incorporate nitrogen atoms into graphene basal plane. The special nanoporous structure combined with nitrogen content of 7.41at.% endows the nitrogen-doped graphene electrode material with super capacitance up to 170Fg(-1), high rate performance, and excellent cycling stability.

[Effects of UV radiation on the aggregation performance of small molecular organic acids].

This study systematically investigated the effects of UV radiation on the aggregation of small molecular aliphatic carboxylic acids and phenolic acids by jar test. Experimental results show that solution pH has little effect on the coagulation of small molecular aliphatic carboxylic acids including citric acid, oxalic acid, tartaric acid, and succinic acid. For the solutions pretreated with UV light, the removal rates of the selected aliphatic carboxylic acids in coagulation are higher than that without UV radiation. Further study shows that photochemical reactions occur during UV radiation which decreases the negative charge in aliphatic carboxylic acids, and thereby increases their aggregation properties. Different from aliphatic carboxylic acids, phenol, salicylic acid, and benzoic acid have poor coagulation properties, and UV radiation does not have notable effects on their aggregation in the coagulation process. The coagulation performance of tannic acid is better than the other phenolic acids. At pH = 6, its removal rate is above 90%, which may be contributed to the aliphatic carboxylic acid structure in its molecular. Meanwhile, the large molecular of tannic acid is also easier to be adsorbed by the hydrolysis products of PAC1.

[Study on the stability variation mechanism of humic acid water solution after radiated by the UV light].

Humic acid widely presents in various surface waters. Molecular structure has significant impacts on its physical and chemical properties. To explore the stability variation of humic acid before and after the UV light radiation, spectroscopic and electrochemical analysis were applied in this paper. Structural parameters selected in the experiments include reactive sites, such as phenolic hydroxyl and carboxyl contents, Zeta potential, and colloidal size. It was found that there was little humic acid being removed in the solution without UV radiation pretreatment; while its remove ratio increased notably with radiation time. After 3 h pretreatment, humic acid removal ratio was above 80% in coagulation. Spectroscopy analysis results showed that partial of the groups with fluorescent effects might be shed or rearranged after the radiation; while its aromatic structure was not destroyed. Both the Zeta potential and average colloidal size decreased with the radiation time, which was not conducive to the aggregation of humic acid. However, -OH content decreased slightly after the UV radiation, and new carboxyl and carbonyl groups formed simultaneously. The increasing of the reactive sites and the improvement of the reaction effectiveness were the major reasons leading to humic acid stability decrease in PAC! coagulation.

[Clinicopathological and prognostic analysis of 178 patients with hypopharyngeal cancer].

OBJECTIVE: To study the clinicopathological characteristics and the prognostic factors in patients with hypopharyngeal cancer. METHODS: Clinical and pathological data of 178 cases with hypopharyngeal cancer from January 2000 to December 2006 were studied. RESULTS: Of the 178 hypopharyngeal cancer, the median survival time was 42.8 months (1 - 127 months). Total 3- and 5-year survival rates were 47% and 35%, respectively. The 5-year survival rates of stage I + II, stage III and stage IV were 76.2%, 46.7% and 29.6%, respectively. The second primary carcinoma occurred in 14.0% patients (25/178), of them 18 patients with synchronous carcinoma and 7 patients with metachronous carcinoma. The independent risk factors associated with the prognosis of these patients were T staging, N staging, clinical staging, performance status (PS), smoking index and treatment model (all P < 0.01). Multivariate Cox analysis showed that smoking index, staging of tumor and treatment were independent risk factors of prognosis. The rate of larynx function preservation was increasing with years from 2000 to 2006. CONCLUSIONS: Surgery plus radiotherapy is the most important treatment for the patients with hypopharyngeal cancer. Tumor stage and treatment model are important predictors of survival in patients with hypopharyngeal cancer.

[Effect of ozone-UV pretreatment on coagulation of raw water with high organic matter].

Humic acid as a model pollutant, this paper aims to evaluate the effect of ozonation, ultraviolet irradiation and ozone-UV (UltraViolet) pretreatment process on the coagulation performance of raw water with high organics. The results indicated that three kinds of pretreatment had obvious mineralization on soluble humic acid in the raw water, and UV and ozone-UV pretreatment had a strengthening effect on the later coagulation process. With the increase of adding ozone dose and extension of UV irradiation, a decline in both content of TOC and turbidity were observed. Under the ozonation pretreatment process, when the concentration of ozone dose (O3/C) was 9.0 mg/mg, 47% of humic acid could be removed by pretreatment, the content of TOC and the turbidity of the filtrated water was 3.5 mg/L and 2.6 NTU, respectively. With the UV pretreatment process, after 3 h UV irradiation, 52% of soluble organic matter could be removed by pretreatment, and the content of TOC and the turbidity of the filtrated water were 2.0 mg/L and 1.0 NTU, respectively. Furthermore, the UV/O3 combined system was better than separate system. The optimum in combined pretreatment process was that the concentration of ozone dose (O3/C) was 1.0 mg/mg, the time of UV irradiation was 1 h, the TOC of the filtrated water was 2. 6 mg/L and the turbidity of that was less than 1.0 NTU. The mineralization effect under various pretreatment processes was achieved by the oxidation of OH, and at the same time the construction of humic acid was changed by pre-oxidation. As a result, the stability of the Reunion construction of humic acid was reduced which promoted the removal of the organic matter during the coagulation process.

[Effect of PTU on the expression of thyroid TPO, Tg mRNA in rats].

OBJECTIVE: To explore the mechanism and the compensation proceeding of thyroid hyperplasia caused by PTU. METHODS: PTU was administered to rats by gavage at a dose of 5.0 mg/kg B. W for 3, 6, 9, 12, 15, 18, 21 days respectively. All animals were sacrificed after the last dosage, and the expression of TPO and Tg in thyroid was detected by RT-PCR. The serum thyroid hormones were measured by chemoluminescence. RESULTS: Compared with the control group, the TPO mRNA levels of PTU groups were increased, while the Tg mRNA levels were decreased significantly. Serum TT3, TT4 in rats treated with PTU demonstrated a descending trend, while serum TSH showed an ascending trend, and the significant differences were observed after 6 days treating with PTU. CONCLUSION: The interference of PTU on thyroid may relate to inhibiton of Tg gene transcription. The enhancement of TPO gene transcription can't compensate the thyroid function sufficiently.