Analysis on methane production from various coal slime fermentations based on metagenomics.

Metagenomic sequencing technology was applied to evaluate differences in the anaerobic fermentation process of coal slimes by analyzing microbial diversity, functional activity structure, and cooperative relationship during the anaerobic fermentation of coal slimes with different coal ranks. The obtained results showed that the production of biomethane from coal slime was decreased by increasing metamorphism degree. Internal reason was higher abundance of microbial community in low rank coal slimes compared to that in high rank coal which had higher activity in the gene expression of key steps such as hydrolysis and acidification, methanation and the production of hydrogen and acetic acid. Acetic acid decarboxylation and CO2 reduction are two key pathways of methanation process. At the same time, K11261 (formylmethanofuran dehydrogenase subunit) and K01499 (methenyltetrahydromethanopterin cyclohydrolase) genes were further enriched in low rank slime systems, which enhanced the proportion of CO2 reduction in methanation pathway and was beneficial to biomethane production. Research revealed the roles of different coal slime ranks in biomethane production process and is considered as an important reference significance for further exploration of coal slime resource utilization.

The characteristics of solid-phase substrate during the co-fermentation of lignite and straw.

Co-fermentation of lignite and biomass has been considered as a new approach in achieving clean energy. Moreover, the study of the characteristics of solid phase in the synergistic degradation process is of great significance in revealing their synergistic relationship. Accordingly, in order to produce biogas, lignite, straw, and the mixture of the two were used as the substrates, the solid phase characteristics of which were analyzed before and after fermentation using modern analytical methods. The results revealed that the mixed fermentation of lignite and straw promoted the production of biomethane. Moreover, the ratios of C/O and C/H were found to be complementary in the co-fermentation process. Furthermore, while the relative content of C-C/C-H bonds was observed to be significantly decreased, the aromatics degree of lignite was weakened. Also, while the degree of branching increased, there found to be an increase in the content of cellulose amorphous zone, which, consequently, led to an increase in the crystallinity index of the wheat straw. Hence, the results provide a theoretical guidance for the efficient utilization of straw and lignite.

Microdroplet-Based In Situ Characterization Of The Dynamic Evolution Of Amorphous Calcium Carbonate during Microbially Induced Calcium Carbonate Precipitation.

Amorphous calcium carbonate (ACC) plays an important role in microbially induced calcium carbonate precipitation (MICP), which has great potential in broad applications such as building restoration, CO2 sequestration, and bioremediation of heavy metals, etc. However, our understanding of ACC is still limited. By combining microscopy of cell-laden microdroplets with confocal Raman microspectroscopy, we investigated the ACC dynamics during MICP. The results show that MICP inside droplets can be divided into three stages: liquid, gel-like ACC, and precipitated CaCO3 stages. In the liquid stage, the droplets are transparent. As the MICP process continues into the gel-like stage, the ACC structure appears and the droplets become opaque. Subsequently, dissolution of the gel-like structure is accompanied by growth of precipitated CaCO3 crystals. The size, morphology, and lifetime of the gel-like structures depend on the Ca2+ concentration. Using polystyrene colloids as tracers, we find that the colloids exhibit diffusive behavior in both the liquid and precipitated CaCO3 stages, while their motion becomes arrested in the gel-like ACC stage. These results provide direct evidence for the formation-dissolution process of the ACC-formed structure and its gel-like mechanical properties. Our work provides a detailed view of the time evolution of ACC and its mechanical properties at the microscale level, which has been lacking in previous studies.

MT1G inhibits the growth and epithelial-mesenchymal transition of gastric cancer cells by regulating the PI3K/AKT signaling pathway.

Gastric carcinoma (GC) is a malignant tumor that has high mortality and morbidity worldwide. Although many efforts have been focused on the development and progression of GC, the underlying functional regulatory mechanism of GC needs more clarification. Metallothionein 1G (MT1G) is a member of the metallothionein family (MTs), and hypermethylation of MT1G occurred in a variety of cancers, including gastric cancer. However, the functional mechanism of MT1G in GC remains unclear. Here, we demonstrated that MT1G was down-regulated in GC tissues and cells. Overexpression of MT1G inhibited cell proliferation, foci formation and cell invasion, while knockdown of MT1G increased cell proliferation, foci formation and cell invasion. In addition, MT1G overexpression inhibited cell cycle progression and MT1G deficiency exerted opposite phenotype. p-AKT was negatively regulated by MT1G. In summary, our study reveals that MT1G exerts crucial role in regulating of cell proliferation and migration of gastric cancer, providing new insights for MT1G-related pathogenesis and a basis for developing new strategies for treatment of GC.

The biochemical mechanism of enhancing the conversion of chicken manure to biogenic methane using coal slime as additive.

To improve the efficiency of methane production from chicken manure (CM) anaerobic digestion, the mechanism of coal slime (CS) as an additive on methane production characteristics were investigated. The results showed that adding an appropriate amount of CS quickened the start of the fermentation and effectively increased the methane yield. In addition, the pH changed in a stable manner in the liquid phase, and the concentrations of total ammonia nitrogen (TAN) and free ammonia nitrogen (FAN) were reduced. Moreover, organic matter was decomposed and volatile fatty acids (VFAs) were consumed effectively. The abundance of Bacteroides in the bacterial community and Methanosarcina in the archaea was increased. In addition, the reduction of CO2 was the main methanogenic pathway, and adding CS raised the abundance of genes for key enzymes in metabolic pathways during methane metabolism. The results provide a novel method for the efficient methane production from CM.

Co-existing siderite alleviates the Fe(II) oxidation-induced inactivation of Fe(III)-reducing bacteria.

Abiotic Fe (II) oxidation widely occurs in the natural subsurface environment and engineered dynamic processes, which possibly impacts the growth of indigenous microbes. As previously discovered, the oxidation of aqueous Fe2+ at neutral pH effectively inactivates iron-reducing bacteria Shewanella oneidensis strain MR-1 (MR-1). Herein, the impacts of co-existing iron mineral on the oxidation of aqueous Fe2+ and the subsequent disinfection activity on MR-1 were investigated with siderite selected as a representative iron mineral in the subsurface environment. The oxidation rate of aqueous Fe2+ and the amount of generated OH radical increased as the content of siderite increased, while the MR-1 inactivation was alleviated. An initial concentration of 2.0 × 106 CFU/mL MR-1 was inactivated by about 2.7 orders of magnitude during oxidation of 0.2 mM FeSO4 alone for 30 min, which was reduced to only about 0.6 orders of magnitude in the presence of 4.3 mM co-existing siderite. ROS scavenging results confirmed that the OH radical generated in the bulk solution was not the leading role for the inactivation of MR-1. Morphological changes of the cells observed by SEM demonstrated that the disruption of the cell membrane was alleviated by siderite, which was further supported by the XRD and FTIR spectra. The underlying mechanism was proposed to be the reduced contact time of Fe2+ and MR-1 cells due to the accelerated oxidation. This work provides new insights into the disinfection behavior of heterogeneous Fe (II) oxidation on iron cycling bacterial in the natural environment.

Neuronal pentraxin II (NPTX2) hypermethylation promotes cell proliferation but inhibits cell cycle arrest and apoptosis in gastric cancer cells by suppressing the p53 signaling pathway.

Gastric cancer is a considerable health burden worldwide. DNA methylation, a major epigenetic phenomenon, is closely related to the pathogenesis of cancer. Neuronal pentraxin II (NPTX2) has been found to be hypermethylated in several cancers such as glioblastoma and pancreatic cancer. However, the roles of NPTX2 in gastric cancer have not been reported. To explore this issue, NPTX2 expression in gastric cancer cells was assessed by western blot and quantitative real-time polymerase chain reaction (qRT-PCR). The methylation analysis of NPTX2 was performed by qRT-PCR as well as methylation-specific PCR (MS-PCR). The effects of NPTX2 on gastric cancer cell proliferation, apoptosis and cell cycle were detected by colony formation, CCK-8 and flow cytometry assays, respectively. The interaction of NPTX2 with the p53 signaling pathway was evaluated by western blot. Our study found the down-regulated expression of NPTX2 in gastric cancer cells compared with human gastric mucosal cells. In addition, the hypermethylation of NPTX2 was observed in gastric cancer cells, which was correlated with the low expression of NPTX2. Moreover, NPTX2 inhibited gastric cancer cell proliferation, inhibited apoptosis and induced cell cycle arrest. Furthermore, NPTX2 enhanced the protein expression of p53, p21 and PTEN to activate the p53 signaling pathway. Therefore, NPTX2 hypermethylation caused the downregulation of NPTX2 expression, which could promote cell proliferation, inhibit apoptosis and cause cell cycle arrest in gastric cancer cells by suppressing the p53 signaling pathway. Therefore, NPTX2 may be crucial for the progression of gastric cancer.

Efficient utilization of coal slime using anaerobic fermentation technology.

In order to increase the utilization of coal slime, realize efficient utilization of resources and protect the environment, the feasibility of anaerobic fermentation technology employing coal slime was explored. The biodegradation of coal slimes and its influence on the utilization characteristics were analyzed using biogas production simulations, drying dehydration and thermogravimetric (TG) analysis. The results showed that the organic matter in various coal slimes could be converted to biomethane. In addition, the main methanogenic pathway was the reduction of CO2. Moreover, lower the metamorphic degree of coal slimes and higher the ash content, more conducive were they to the dehydration of coal slimes. After biodegradation, the temperatures of four coal slimes during the stages of release of moisture, volatile combustion, residual coke combustion and burnout advanced to varying degrees. Moreover, the combustion performance improved. The research results provided a novel idea for the efficient utilization of coal slime.

Low-Complexity Soft-Output Signal Detection Based on Improved Kaczmarz Iteration Algorithm for Uplink Massive MIMO System.

For multi-user uplink massive multiple input multiple output (MIMO) systems, minimum mean square error (MMSE) criterion-based linear signal detection algorithm achieves nearly optimal performance, on condition that the number of antennas at the base station is asymptotically large. However, it involves prohibitively high complexity in matrix inversion when the number of users is getting large. A low-complexity soft-output signal detection algorithm based on improved Kaczmarz method is proposed in this paper, which circumvents the matrix inversion operation and thus reduces the complexity by an order of magnitude. Meanwhile, an optimal relaxation parameter is introduced to further accelerate the convergence speed of the proposed algorithm and two approximate methods of calculating the log-likelihood ratios (LLRs) for channel decoding are obtained as well. Analysis and simulations verify that the proposed algorithm outperforms various typical low-complexity signal detection algorithms. The proposed algorithm converges rapidly and achieves its performance quite close to that of the MMSE algorithm with only a small number of iterations.

[Effect of danusertib on cell cycle, apoptosis and autophagy of hepatocellular carcinoma HepG2 cells in vitro].

OBJECTIVE: To investigate the effect of danusertib (Danu), an inhibitor of Aurora kinase, on the proliferation, cell cycle, apoptosis, and autophagy of hepatocellular carcinoma HepG2 cells and explore the underlying mechanisms. METHODS: MTT assay was used to examine the effect of Danu on the viability of HepG2 cells to determine the IC50 of Danu. The effect of Danu on cell cycle distribution, apoptosis and autophagy were determined using flow cytometry. Western blotting was used to detect the expressions of the proteins related to cell cycle, apoptosis and autophagy. Chloroquine was used to suppress Danuinduced autophagy to test the apoptosis-inducing effect of Danu. RESULTS: Danu significantly inhibited the proliferation of HepG2 cells with IC50 of 39.4 µmol and 14.4 µmol at 24 h and 48 h, respectively. Danu caused cell cycle arrest in G2/M phase in HepG2 cells and led to polyploidy accumulation via up-regulating the expressions of p53 and p21 and down-regulating the expressions of cyclin B1 and DC2. Danu also caused apoptosis of HepG2 cells through up-regulating the expressions of Bax, Puma, cleaved caspase-3, cleaved caspase-9, cleaved PARP and cytochrome C and down-regulating the expressions of Bcl-xl and Bcl-2. Danu induced autophagy via activating AMPK signaling and inhibiting PI3K/PTEN/AKT/mTOR axis, and inhibition of Danu-induced autophagy with chloroquine enhanced the pro-apoptotic effect of Danu. CONCLUSIONS: Danu inhibits cell proliferation and induces cell cycle arrest in G2/M phase, apoptosis and cytoprotective autophagy in HepG2 cells.

MiR-548an, Transcriptionally Downregulated by HIF1α/HDAC1, Suppresses Tumorigenesis of Pancreatic Cancer by Targeting Vimentin Expression.

Hypoxic microenvironments contribute to the tumorigenesis of numerous cancers by regulating the expression of a subset of miRNAs called "hypoxiamiRs." However, the function and mechanism of these deregulated miRNAs in hypoxic microenvironments within pancreatic cancers remain undefined. This study demonstrates that miR-548an is significantly downregulated in pancreatic cancer tissues and correlates with increased tumor size, advanced TNM stage, distant metastasis, and poor prognosis. Moreover, the overexpression of miR-548an significantly inhibited the proliferation and invasion of pancreatic cancer cells in vitro and in vivo We further revealed that hypoxia-induced factor-1α (HIF-1α) induces the downregulation of miR-548an in pancreatic cancer cells during hypoxia. Our co-IP and ChIP assays revealed that HIF-1α and histone deacetylase 1 (HDAC1) form a complex and bind to the hypoxia response elements (HRE) on the miR-548an promoter. In addition, inhibition of HDAC1 with trichostatin A antagonizes the suppression of miR-548 by hypoxia. Our dual luciferase assay validated that miR-548an directly binds to the 3' untranslated region of vimentin mRNA. The downregulation of vimentin suppresses the proliferation and invasion of pancreatic cancer cells in vitro and in vivo In addition, vimentin was inversely correlated with miR-548an expression in pancreatic cancer samples. In conclusion, our findings suggest that the HIF-1α-HDAC1 complex transcriptionally inhibits miR-548an expression during hypoxia, resulting in the upregulation of vimentin that facilitates the pancreatic tumorigenesis. Mol Cancer Ther; 15(9); 2209-19. ©2016 AACR.

Electrooxidation of Ethanol and Methanol Using the Molecular Catalyst [{Ru4O4(OH)2(H2O)4}(γ-SiW10O36)2](10.).

Highly efficient electrocatalytic oxidation of ethanol and methanol has been achieved using the ruthenium-containing polyoxometalate molecular catalyst, [{Ru4O4(OH)2(H2O)4}(γ-SiW10O36)2](10-) ([1(γ-SiW10O36)2](10-)). Voltammetric studies with dissolved and surface-confined forms of [1(γ-SiW10O36)2](10-) suggest that the oxidized forms of 1 can act as active catalysts for alcohol oxidation in both aqueous (over a wide pH range covering acidic, neutral, and alkaline) and alcohol media. Under these conditions, the initial form of 1 also exhibits considerable reactivity, especially in neutral solution containing 1.0 M NaNO3. To identify the oxidation products, preparative scale bulk electrolysis experiments were undertaken. The products detected by NMR, gas chromatography (GC), and GC-mass spectrometry from oxidation of ethanol are 1,1-diethoxyethane and ethyl acetate formed from condensation of acetaldehyde or acetic acid with excess ethanol. Similarly, the oxidation of methanol generates formaldehyde and formic acid which then condense with methanol to form dimethoxymethane and methyl formate, respectively. These results demonstrate that electrocatalytic oxidation of ethanol and methanol occurs via two- and four-electron oxidation processes to yield aldehydes and acids. The total faradaic efficiencies of electrocatalytic oxidation of both alcohols exceed 94%. The numbers of aldehyde and acid products per catalyst were also calculated and compared with the literature reported values. The results suggest that 1 is one of the most active molecular electrocatalysts for methanol and ethanol oxidation.

Hypoxia-induced lncRNA-NUTF2P3-001 contributes to tumorigenesis of pancreatic cancer by derepressing the miR-3923/KRAS pathway.

Recent studies indicate that long non-coding RNAs (lncRNAs) play crucial roles in numerous cancers, while their function in pancreatic cancer is rarely elucidated. The present study identifies a functional lncRNA and its potential role in tumorigenesis of pancreatic cancer. Microarray co-assay for lncRNAs and mRNAs demonstrates that lncRNA-NUTF2P3-001 is remarkably overexpressed in pancreatic cancer and chronic pancreatitis tissues, which positively correlates with KRAS mRNA expression. After downregulating lncRNA-NUTF2P3-001, the proliferation and invasion of pancreatic cancer cell are significantly inhibited both in vitro and vivo, accompanying with decreased KRAS expression. The dual-luciferase reporter assay further validates that lncRNA-NUTF2P3-001 and 3'UTR of KRAS mRNA competitively bind with miR-3923. Furthermore, miR-3923 overexpression simulates the inhibiting effects of lncRNA-NUTF2P3-001-siRNA on pancreatic cancer cell, which is rescued by miR-3923 inhibitor. Specifically, the present study further reveals that lncRNA-NUTF2P3-001 is upregulated in pancreatic cancer cells under hypoxia and CoCl2 treatment, which is attributed to the binding of hypoxia-inducible factor-1α (HIF-1α) to hypoxia response elements (HREs) in the upstream of KRAS promoter. Data from pancreatic cancer patients show a positive correlation between lncRNA-NUTF2P3-001 and KRAS, which is associated with advanced tumor stage and worse prognosis. Hence, our data provide a new lncRNA-mediated regulatory mechanism for the tumor oncogene KRAS and implicate that lncRNA-NUTF2P3-001 and miR-3923 can be applied as novel predictors and therapeutic targets for pancreatic cancer.

Electrochemical reduction of aromatic ketones in 1-butyl-3-methylimidazolium-based ionic liquids in the presence of carbon dioxide: the influence of the ketone substituent and the ionic liquid anion on bulk electrolysis product distribution.

Electrochemical reduction of aromatic ketones, including acetophenone, benzophenone and 4-phenylbenzophenone, has been undertaken in 1-butyl-3-methylimidazolium-based ionic liquids containing tetrafluoroborate ([BF4](-)), trifluoromethanesulfonate ([TfO](-)) and tris(pentafluoroethyl)trifluorophosphate ([FAP](-)) anions in the presence of carbon dioxide in order to investigate the ketone substituent effect and the influence of the acidic proton on the imidazolium cation (C2-H) on bulk electrolysis product distribution. For acetophenone, the minor products were dimers (<10%) in all ionic liquids, which are the result of acetophenone radical anion coupling. For benzophenone and 4-phenylbenzophenone, no dimers were formed due to steric hindrance. In these cases, even though carboxylic acids were obtained, the main products generated were alcohols (>50%) derived from proton coupled electron transfer reactions involving the electrogenerated radical anions and C2-H. In the cases of both acetophenone and benzophenone, the product distribution is essentially independent of the ionic liquid anion. By contrast, 4-phenylbenzophenone shows a product distribution that is dependent on the ionic liquid anion. Higher yields of carboxylic acids (∼40%) are obtained with [TfO](-) and [FAP](-) anions because in these ionic liquids the C2-H is less acidic, making the formation of alcohol less favourable. In comparison with benzophenone, a higher yield of carboxylic acid (>30% versus ∼15%) was obtained with 4-phenylbenzophenone in all ionic liquids due to the weaker basicity of 4-phenylbenzophenone radical anion.

Remarkable sensitivity of the electrochemical reduction of benzophenone to proton availability in ionic liquids.

The reduction of benzophenone was investigated in five different ionic liquids by using transient cyclic voltammetry, near steady-state voltammetry, and numerical simulation. Two reversible, well-resolved one-electron-reduction processes were observed in dry (≤20 ppm water, ca. 1 mM)) 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([Bmpyrd][NTf(2)]) and 1-butyl-1-methylpiperidinium bis(trifluoromethylsulfonyl)imide ([Bmpipd][NTf(2)]), which did not contain any readily available proton source. Upon addition of water, the second process became chemically irreversible and shifted to a more positive potential by approximately 600 mV; moreover, the two reduction processes merged into a single two-electron proton-coupled process when about 0.6 M H(2)O was present. This large dependence of potential on water content, which was not observed in molecular solvents (electrolyte), was explained by a reaction mechanism that incorporated protonation and hydrogen-bonding interactions of the benzophenone dianion with as many as seven water molecules. In the three imidazolium-based ionic liquids used herein, the first benzophenone-reduction process was again reversible, whilst the second reduction process became chemically irreversible owing to the availability of the C2-H imidazolium protons in these ionic liquids. The reversible potentials for benzophenone reduction were remarkably independent of the identity of the ionic liquids, thereby implying either weak interactions with the ionic liquids or relatively insignificant differences in the levels of ion-pairing. Thus, the magnitude of the separation of the potentials of the reversible first and irreversible second reduction processes mainly reflected the proton availability from either the ionic liquid itself or from adventitious water. Consequently, voltammetric reduction of benzophenone provides a sensitive tool for the determination of proton availability in ionic liquids.

Simplifying the evaluation of graphene modified electrode performance using rotating disk electrode voltammetry.

Graphene modified electrodes have been fabricated by electrodeposition from an aqueous graphene oxide solution onto conducting Pt, Au, glassy carbon, and indium tin dioxide substrates. Detailed investigations of the electrochemistry of the [Ru(NH(3))(6)](3+/2+) and [Fe(CN)(6)](3-/4-) and hydroquinone and uric acid oxidation processes have been undertaken at glassy carbon and graphene modified glassy carbon electrodes using transient cyclic voltammetry at a stationary electrode and near steady-state voltammetry at a rotating disk electrode. Comparisons of the data with simulation suggest that the transient voltammetric characteristics at graphene modified electrodes contain a significant contribution from thin layer and surface confined processes. Consequently, interpretations based solely on mass transport by semi-infinite linear diffusion may result in incorrect conclusions on the activity of the graphene modified electrode. In contrast, steady-state voltammetry at a rotating disk electrode affords a much simpler method for the evaluation of the performance of graphene modified electrode since the relative importance of the thin layer and surface confined processes are substantially diminished and mass transport is dominated by convection. Application of the rotated electrode approach with carbon nanotube modified electrodes also should lead to simplification of data analysis in this environment.