Mechanistic and quantitative profiling of electro-Fenton process for wastewater treatment.

Electro-Fenton (EF) process represents an energy-efficient and scalable advanced oxidation technology (AOT) for micropollutants removal in wastewaters. However, mechanistic profiling and quantitation of contribution of each subprocess (i.e., adsorption at electrode, coagulation, radical oxidation, electrode oxidation/reduction, and H2O2 oxidation) to the overall degradation are substantially unclear, resulting in difficulty in tunability and optimization for different treatment scenarios. In this study, we investigated degradation kinetics of a target micropollutant in an EF system. The contribution of all possible subprocesses was elucidated by comparing the observed degradation rate in the EF system with the sum of the kinetics in each subprocess. The results indicated that the overall degradation can be attributed to the synergistic action of the above-mentioned subprocesses. The radical oxidation accounts for 87% elimination, followed by electrode reoxidation/reduction of 7.7%. These results not only advance the fundamental understanding of synergistic effect in EF system, but also open new possibilities to optimize these techniques for better scalability. In addition, the methodology in this study could potentially boost the in-depth exploration of subprocess contribution in other Fenton-like systems.

Evaluation of biochar addition and circulation control strengthening measures on efficiency and microecology of food waste treatment in anaerobic reactor.

The process of strengthening an expanded granular sludge blanket (EGSB) reactor under ammonia nitrogen stress conditions and by adopting three strengthening measures, namely, opening the circulation (OC), adding modified biochar (MB), adding modified biochar along with opening the circulation (MBOC), to treat food waste was studied. When the ammonia nitrogen concentration of influent increased to 1200 mg/L, the removal rate of COD reduced to about 75%, while the removal rate of ammonia nitrogen was about 6%. The average COD removal rate of the anaerobic reactor in the last 5 days of each operating cycle i.e. OC, MB and MBOC, was 85.51%, 84.11% and 90.03%, respectively. At the 30th day of each treatment-OC, MB and MBOC, the protease content in the sludge was 44.61, 42.47, 46.24 NH2-N (mg)/mg, respectively. and the content of coenzyme F420 was 0.244, 0.217 and 0.267 mmol/g, respectively. Proteobacteria was the most abundant phylum in the stage I (OC), reaching 34.36%. It was accounted for 16.68% and 21.38%, respectively, in the stage II (MB) and stage III (MBOC). The dominant archaea in the three stages were Methanosaeta, whose abundance was 38.98% in stage I, which increased to 64.94% and 64.01% in stage II and III, respectively. Among the active carbohydrate enzymes, the gene abundance of Glycoside transferases in the MBOC stage was the largest among the three stages.

Roles of modified biochar in the performance, sludge characteristics, and microbial community features of anaerobic reactor for treatment food waste.

Anaerobic digestion (AD) is a green technology widely applied to food waste treatment. Although the AD has high efficiency, instability often occurs. The main purpose of the study is to understand the mechanism of modified biochar improving AD performance. The effects of different modified biochar on the efficiency and microecology of an anaerobic reactor treating food waste were investigated. Bagasse biochar was used as the substrate to explore the effects of iron-modified (A), chitosan-modified (B), iron-chitosan-modified (C) and iron­magnesium-chitosan-modified (D) biochar on the anaerobic digestion process, sludge characteristics and microbial community. The results show that the average COD removal efficiency of the four reactors during the last five days of the experimentation period was 86.95%, 85.90%, 92.22% and 93.29%, respectively. Adding iron­magnesium-chitosan-modified biochar could improve the efficiency of COD removal in the anaerobic reactor under ammonia nitrogen stress. On day 10 of operation, the content of coenzyme F420 in the sludge of anaerobic reactors C and D reached to 0.44 and 0.57 mmol/g, respectively, indicating that the metal-chitosan complex biochar could promote the production of coenzyme F420 in the early stage of the experiment. Within the four anaerobic reactors, Firmicutes, Bacteroidetes, Proteobacteria and Chloroflexi were the dominant bacteria, and the abundance of Chloroflexi reached a maximum of 26.24% in the reactor C. As for archaea, Methanobacterium and Methanothrix were the most dominant accounting for 44.03%, 49.88%, 31.29%, 52.01% and 38.34%, 34.52%, 50.9%, 35.72% respectively in the four reactors. KEGG functional analysis showed that the energy metabolism of bacteria and archaea in the reactor D was the largest among the four reactors. Meanwhile, the gene abundance associated with carbohydrate metabolism and membrane transport of microorganisms in the reactor D was greater than that of other groups.

Effects of exposure to polyether sulfone microplastic on the nitrifying process and microbial community structure in aerobic granular sludge.

The effects of polyether sulfone (PES) microplastic concentration on the nitrifying process of aerobic granular sludge (AGS) were investigated together with the microbial community structure of AGS. The PES microplastic concentration inhibited the removal of ammonia nitrogen only to a small extent. The average total nitrogen removal rate increased by 5.6% after PES addition. On the 30th day, the addition of 0.5 g/L PES inhibited the specific nitrate reduction rate (SNRR) by 38.84 mg N/(g MLSS·h). Nitrite oxidase (NOR) performance of the AGS were inhibited with addition the PES. According to the high-throughput sequencing results, in the presence of PES, the abundance of Bacillales_Incertae Sedis XII reduced, while the abundance of Anaerolineaceaen increased in the AGS. According to the clusters of orthologous groups (COG) and kyoto encyclopedia of genes and genomes (KEGG), the content of cytochrome c-containing reduced and the Amino Acid Metabolism increased with addition 0.5 g/L PES microplastic.

Targeting of the ß6 gene to suppress degradation of ECM via inactivation of the MAPK pathway in breast adenocarcinoma cells.

Integrin ανß6 has emerged as a potential novel target for anticancer and plays a major role in promoting malignant tumor progression. Recent studies indicate that integrin ανß6 occurs in many cancers. However, whether and how ανß6 is regulated by genetic and epigenetic mechanisms in breast cancer remain unknown. In the present study, two different short hairpin RNAs (shRNAs) targeting the ß6 gene were designed and constructed into pSUPER, respectively, which were transfected into the MCF-7 human breast adenocarcinoma cell line. The ß6-shRNA stably transfected cells were successfully established, and significant lower levels of ανß6 mRNA and protein expression were confirmed. Furthermore, inhibition of integrin ανß6 markedly downregulated the expression of matrix metalloproteinase-9 (MMP-9), matrix metalloproteinase-3 (MMP-3) and urokinase plasminogen activator (uPA) in tumor conditioned medium. Furthermore, ß6-shRNA-mediated silencing of the ανß6 gene obviously decreased the expression of ERK1/2. In particular, supression of integrin ανß6 caused significant downregulation of the degradation of basement membrane type IV collagen secretion via modulation of the plasminogen activation cascade. Our results thus indicate that ανß6 plays a fundamental role in promoting invasion and growth of breast adenocarcinoma cells. Taken together, this study revealed that targeting of the ß6 gene by RNA interference (RNAi) could efficiently downregulate ανß6 expression and suppress the ERK1/2-dependent extracellular matrix degradation in vitro, which is dependent upon inactivation of the mitogen-activated protein kinase (MAPK) pathway. These findings may offer a useful therapeutic approach to block invasion and migration of breast cancer cells.

Expression and significance of P53 protein and MDM-2 protein in human gliomas.

BACKGROUND: P53 is one of the most studied tumor suppressors in the cancer research, and over 50% of human tumors carry P53 mutations. MDM-2 is amplified and/or overexpressed in a variety of human tumors of diverse tissue origin. The aim of this study was to examine the expression of P53 protein and MDM-2 protein in gliomas, and to investigate the relationship between the expression of the two proteins and the histopathological grades of glioma. The relationship between MDM-2 protein expression and P53 protein expression was also analyzed. METHODS: The expression of P53 protein and MDM-2 protein was immunohistochemically detected using monoclonal antibodies in 242 paraffin embedded tissues, including 30 normal brain tissues from patients with craniocerebral injury and 212 tissues from patients with primary glioma (grade I - II group: 5 cases of grade I, 119 cases of grade II; and grade III--IV group: 53 cases of grade III, and 35 cases of grade IV). RESULTS: The P53 positive rate was significantly higher in the glioma groups than in the control group (P < 0.0001). The P53 positive rate was significantly higher in glioma tissues of grade III - IV than in glioma tissues of grade I - II group (P = 0.001). The MDM-2 positive rate was significantly higher in glioma groups than in the control group (P < 0.0001). There was no significant difference in the MDM-2 positive rate between the two glioma groups (P = 0.936). The expression of P53 protein was not related to expression of MDM-2 protein (P = 0.069) CONCLUSIONS: Overexpression of P53 protein might be related to the occurrence and progression of glioma. Overexpression of MDM-2 protein may play an important role in glioma tumorigenesis, but may not be involved in glioma progression. The overexpression of MDM-2 protein was an early event in malignant transformation of glioma. MDM-2 may be a key player in glioma in its own right.

[Clinicopathologic evaluation of 36 cases of allergic fungal sinusitis].

OBJECTIVE: To characterize clinicopathological features of allergic fungal sinusitis (AFS). METHODS: Thirty-six cases of AFS were retrieved from the department archival files of Beijing Tongren Hospital from 2002 to 2006. AB-PAS, GMS and MUC5B stain were performed using paraffin-embedded tissues of the cases. Ten cases with available fresh diagnostic tissue were investigated by electron microscopy. RESULTS: Patients included 21 males and 15 females. The age of patients ranged from 11 to 53 years. Atopy was very common in these patients. On plain CT scans, the affected nasal sinuses were filled with soft tissue shadow with patchy hyperdensity. The bony sinus wall showed areas of pressure erosion. Skin antigen tests showed fungal positivity in 31 of 36 cases. Serum levels of the total IgE and/or the specific fungal IgE were elevated in 20 cases. The eosinophil quantity was elevated in 23 cases. Fungal culture was positive in 10 cases. Gross examination showed thick putty secretions within the lesions. Light microscopy showed typical "eosinophilic mucin". Fungal elements were seen with AB-PAS, GMS and MUC5B stains. Electron microscopy demonstrated degranulation by the eosinophils. CONCLUSIONS: "Eosinophilic mucin" is the typical histopathological feature of AFS. AB-PAS, GMS and MUC5B staining methods can used to detect fungal species in mucin. Accurate diagnosis of AFS requires correlations among clinical findings, radiologic examinations, laboratory tests and histopathologic features. However, the ultimate diagnosis requires a histopathologic confirmation.

Increased expression of fascin associated with malignant transformation of sinonasal inverted papilloma.

BACKGROUND: Fascin, an actin binding protein, usually expressed at a low level in normal epithelium, but is significantly increased in transformed epithelial cells and several common carcinomas. In this study, we examined the expression of fascin by immunohistochemistry in sinonasal epithelium with chronic inflammation (control group), exophytic papilloma (EP), inverted papilloma (IP) with dysplasia and cancerated IP (including carcinoma in situ and invasive squamous cell carcinoma, SCC), and furthermore investigated the relationship between fascin expression and formation of malignant IP. METHODS: Fascin expression was immunohistochemically detected using monoclonal antibody against fascin in 86 paraffin embedded tissues, including 10 cases of sinonasal mucosa with chronic inflammation, 10 of EP, 45 of IP with dysplasia (45 cases were divided into three groups: IP with mild dysplasia, IP with moderate dysplasia, and IP with severe dysplasia, 15 cases each), and 21 of cancerated IP. RESULTS: The level of fascin expression was significantly higher in the neoplastic tissue than that in control group. Fascin expression increased gradually with the progression from sinonasal epithelium with chronic inflammation, IP with mild dysplasia, IP with moderate dysplasia, IP with severe dysplasia, to cancerated IP, and significant difference of fascin expression was observed between any two groups of the five. CONCLUSION: Precancerous lesions of IP exhibit elevated levels of fascin that may be associated with carcinogenesis of IP. Fascin may play a role in the formation of IP and EP.

[The change of circulating endothelial cell in blood of rats and pulmonary small artery vascular endothelial cell under acute hypoxia].

AIM: To investigate changes of VEC and CEC under acute hypoxia. METHODS: Observe CEC in blood under acute hypoxia morphologically and count the number of CEC by optical microscope, measure LDH activity of young CEC and VEC by histochemical staining image analysis. RESULTS: LDH activities of VEC in hypoxic groups are lower than that in the group before hypoxia and decrease progressively with hypoxia time. LDH activities of young CEC in groups after hypoxia and before hypoxia are the same and are apparently lower than that of VEC. Before hypoxia most of CEC are aging, the number of CEC from hypoxic groups is greater than that before hypoxia and increases progressively with hypoxia time and most of CEC from hypoxic groups are young. CONCLUSION: The morphology and number of CEC may reflect the extent to which the vascular is injured. LDH activity of VEC may reflect the transformation from VEC into CEC. LDH activity of young CEC may reflect the extent to which the VEC is injured when falling from vascular wall.