Simultaneous biogas upgrading and medium-chain fatty acids production using a dual membrane biofilm reactor.

Utilizing H2-assisted ex-situ biogas upgrading and acetate recovery holds great promise for achieving high value utilization of biogas. However, it faces a significant challenge due to acetate's high solubility and limited economic value. To address this challenge, we propose an innovative strategy for simultaneous upgrading of biogas and the production of medium-chain fatty acids (MCFAs). A series of batch tests evaluated the strategy's efficiency under varying initial gas ratios (v/v) of H2, CH4, CO2, along with varying ethanol concentrations. The results identified the optimal conditions as initial gas ratios of 3H2:3CH4:2CO2 and an ethanol concentration of 241.2 mmol L-1, leading to maximum CH4 purity (97.2 %), MCFAs yield (54.2 ± 2.1 mmol L-1), and MCFAs carbon-flow distribution (62.3 %). Additionally, an analysis of the microbial community's response to varying conditions highlighted the crucial roles played by microorganisms such as Clostridium, Proteiniphilum, Sporanaerobacter, and Bacteroides in synergistically assimilating H2 and CO2 for MCFAs production. Furthermore, a 160-day continuous operation using a dual-membrane aerated biofilm reactor (dMBfR) was conducted. Remarkable achievements were made at a hydraulic retention time of 2 days, including an upgraded CH4 content of 96.4 ± 0.3 %, ethanol utilization ratio (URethanol) of 95.7 %, MCFAs production rate of 28.8 ± 0.3 mmol L-1 d-1, and MCFAs carbon-flow distribution of 70 ± 0.8 %. This enhancement is proved to be an efficient in biogas upgrading and MCFAs production. These results lay the foundation for maximizing the value of biogas, reducing CO2 emissions, and providing valuable insights into resource recovery.

Integrated biogas upgrading and medium-chain fatty acids production for more efficient resource recovery.

The conversion of carbon dioxide (CO2) from biogas into medium-chain fatty acids (MCFAs) represents an eco-friendly resource recovery approach to reduce dependence on fossil fuels and combat global climate change. This study presented the novel concept of integrated resource recovery by coupling biogas upgrading and MCFAs production for the first time. Initially, the impact of different initial ethanol concentrations on chain elongation was examined, determining that an ethanol concentration of 160 mmol/L maximized MCFAs yield at 45.7 mmol/L. Subsequently, using this optimal ethanol supply, the integrated strategy was implemented by connecting two bioreactors in series and maintaining continuous operation for 160-day. The results were noteworthy: upgraded bio-methane purity reached 97.6 %, MCFAs production rate and carbon-flow distribution reached 24.5 mmol/L d-1 and 76.1 %, respectively. In summary, these promising outcomes pioneer a resource recovery approach, enabling the high-value utilization of biogas and the conversion of CO2 into valuable bio-chemicals.

Sewage sludge derived biochar for environmental improvement: Advances, challenges, and solutions.

With the rapid growth yield of global sewage sludge, rational and effective treatment and disposal methods are becoming increasingly needed. Biochar preparation is an attractive option for sewage sludge treatment, the excellent physical and chemical properties of sludge derived biochar make it an attractive option for environmental improvement. Here, the current application state of sludge derived biochar was comprehensively reviewed, and the advances in the mechanism and capacity of sludge biochar in water contaminant removal, soil remediation, and carbon emission reduction were described, with particular attention to the key challenges involved, e.g., possible environmental risks and low efficiency. Several new strategies for overcoming sludge biochar application barriers to realize highly efficient environmental improvement were highlighted, including biochar modification, co-pyrolysis, feedstock selection and pretreatment. The insights offered in this review will facilitate further development of sewage sludge derived biochar, towards addressing the obstacles in its application in environmental improvement and global environmental crisis.

Recovery of methane and acetate during ex-situ biogas upgrading via novel dual-membrane aerated biofilm reactor.

Biological biogas upgrading has been well-proven to be a promising approach for renewable bioenergy recovery, but hydrogen (H2)-assisted ex-situ biogas upgrading is hindered by a large solubility discrepancy between H2 and carbon dioxide (CO2). This study established a new dual-membrane aerated biofilm reactor (dMBfR) to improve the upgrading efficiency. Results showed that dMBfR operated at 1.25 atm H2 partial pressure, 1.5 atm biogas partial pressure, and 1.0 d hydraulic retention time could significantly improve the efficiency. The maximum methane purity of 97.6%, acetate production rate of 34.5 mmol L-1d-1, and H2 and CO2 utilization ratios of 96.5% and 96.3% were achieved. Further analysis showed that the improved performances of biogas upgrading and acetate recovery were positively correlated with the total abundances of functional microorganisms. Taken together, these results suggest that the dMBfR, which facilitates the precise CO2 and H2 supply, is an ideal approach for efficient biological biogas upgrading.

Synergistic effect of hydrogen and nanoscale zero-valent iron on ex-situ biogas upgrading and acetate recovery.

Hydrogen (H2) assisted ex-situ biogas upgrading and liquid chemicals production can augment the fossil fuel-dominated energy market, and alleviate CO2-induced global warming. Recent investigations confirmed that nanoscale zero-valent iron (nZVI) enabled the enhancement of anaerobic digestion for biogas production. However, little is known about the effect of nZVI on the downstream ex-situ biogas upgrading. Herein, different levels (0 mg L-1, 100 mg L-1, 200 mg L-1, 500 mg L-1, 1000 mg L-1, 2000 mg L-1) of nZVI were added for H2-assisted ex-situ biogas upgrading, to study whether nZVI could impact the biomethane purity and acetate yield for the first time. Results showed that all tested nZVI levels were favorable for biogas upgrading in the presence of H2, the highest biomethane content (94.1 %, v/v), the CO2 utilization ratio (95.9 %), and acetate yield (19.4 mmol L-1) were achieved at 500 mg L-1 nZVI, respectively. Further analysis indicated that increased biogas upgrading efficiency was related to an increase in extracellular polymeric substances, which ensures the microbial activity and stability of the ex-situ biogas upgrading. Microbial community characterization showed that the Petrimonas, Romboutsia, Acidaminococcus, and Clostridium predominated the microbiome during biogas upgrading at 500 mg L-1 nZVI with H2 supply. These results suggested that nZVI and H2 contributed jointly to promoting the bioconversion of CO2 in biogas to acetate. The findings could be helpful for paving a new way for efficient simultaneous ex-situ biogas upgrading and liquid chemicals recovery.

Overview of recent progress in exogenous hydrogen supply biogas upgrading and future perspective.

With the rapid development of renewable and sustainable energy, biogas upgrading for producing high-quality biomethane as an alternative to natural gas has attracted worldwide attention. This paper comprehensively reviews the current state of biogas upgrading technologies. The advances in physicochemical, photosynthetic autotrophic, and chemical autotrophic biogas upgrading technologies are briefly described with particular attention to the key challenges. New chemical autotrophic biogas upgrading strategies, such as direct and indirect exogenous hydrogen supply, for overcoming barriers to biogas upgrading and realizing highly efficient bioconversion of carbon dioxide are summarized. For each approach to exogenous hydrogen supply for biogas upgrading, the key findings and technical limitations are summarized and critically analyzed. Finally, future developments are also discussed to provide a reference for the development of biogas upgrading technology that can address the global energy crisis and climate change issues related to the application of biogas.

Advances in pretreatment of lignocellulosic biomass for bioenergy production: Challenges and perspectives.

As a clean and renewable energy, bioenergy is one of the most promising alternatives to fossil fuels. Lignocellulose possesses great potential for bioenergy production, but the recalcitrant and heterogeneous structure limits its application. Pretreatment technology offers an effective solution to fractionate the main components of the lignocellulose and uncover the available cellulose. The obtained feedstock can be applied to bioconversion into energy, e.g., bioethanol, biogas, biohydrogen, etc. Here, the current state of lignocellulose pretreatment technologies was comprehensively reviewed, the advances in bioenergy production from pretreated lignocellulose was described, with particular attention to key challenges involved. Several new strategies for overcoming pretreatment barriers to realize highly efficient lignocellulose bioconversion were highlighted. The insights given in this review will facilitate further development on lignocellulosic bioenergy production, towards addressing the global energy crisis and climate change related to the use of fossil fuels.

Optimal Function Prediction of Key Aberrant Genes in Early-onset Preeclampsia Using a Modified Network-based Guilt by Association Method.

BACKGROUND: To predict the optimal functions of key aberrant genes in early-onset preeclampsia (EOPE) by using a modified network-based gene function inference method. METHODS: First, differentially expressed genes (DEGs) were extracted using linear models for microarray data (LIMMA) package. Then the Spearman's rank correlation coefficient was calculated to assess co-expressed strength of each interaction between DEGs, based on which the co-expressed genes network was constructed to vividly exhibit their interlinking relationship. Subsequently, Gene ontology (GO) annotations for EOPE were collected according to known confirmed database and DEGs. Ultimately, the multifunctionality algorithm was used to extend the "guilt by association" method based on the co-expressed network, and a 3-fold cross validation was operated to evaluate the accuracy of the algorithm. RESULTS: During the process, the GO terms, of which the area under the curve (AUC) over 0.7 were screened as the optimal gene functions for EOPE. Six functions including the ion binding and cellular response to stimulus were determined as the optimal gene functions. CONCLUSION: Such findings should help to better understand the pathogenesis of EOPE, so as to provide some references for clinical diagnosis and treatment in the future.

A new Seasonal Difference Space-Time Autoregressive Integrated Moving Average (SD-STARIMA) model and spatiotemporal trend prediction analysis for Hemorrhagic Fever with Renal Syndrome (HFRS).

Hemorrhagic fever with renal syndrome (HFRS) is a naturally-occurring, fecally transmitted disease caused by a Hantavirus (HV). It is extremely damaging to human health and results in many deaths annually, especially in Hubei Province, China. One of the primary characteristics of HFRS is the spatiotemporal heterogeneity of its occurrence, with notable seasonal differences. In view of this heterogeneity, the present study suggests that there is a need to focus on trend simulation and the spatiotemporal prediction of HFRS outbreaks. To facilitate this, we constructed a new Seasonal Difference Space-Time Autoregressive Integrated Moving Average (SD-STARIMA) model. The SD-STARIMA model is based on the spatial and temporal characteristics of the Space-Time Autoregressive Integrated Moving Average (STARMA) model first developed by Cliff and Ord in 1974, which has proven useful in modelling the temporal aspects of spatially located data. This model can simulate the trends in HFRS epidemics, taking into consideration both spatial and temporal variations. The SD-STARIMA model is also able to make seasonal difference calculations to eliminate temporally non-stationary problems that are present in the HFRS data. Experiments have demonstrated that the proposed SD-STARIMA model offers notably better prediction accuracy, especially for spatiotemporal series data with seasonal distribution characteristics.

JTC-801 inhibits the proliferation and metastasis of ovarian cancer cell SKOV3 through inhibition of the PI3K - AKT signaling pathway.

Ovarian cancer (OC) is the commonest cause of gynaecological cancer-associated death because of the wide metastasis and frequent recidivation. JTC-801 is a new synthetic compound with the function of reversing pain and anxiety symptoms as a selective opioid receptor-like1 receptor (belonging to the G-protein-coupled receptor) antagonist. We investigated the role and possible mechanisms of JTC-801 in the cell growth and metastasis of OC. It was observed that JTC-801 inhibited the proliferation, invasion and migration of cancer in SKOV3 cells. The apoptosis rate of SKOV3 cells treated with JTC-801 was significantly increased (P<0.05), and the expression results of relevant apoptosis proteins (BCL2, BAX, Active Caspase-3) indicated the JTC-801 could induce the apoptosis of SKOV3. Further, the expression levels of phosphorylated AKT, phosphorylated mTOR, P70 and CyclinD1 in the PI3K/AKT signaling pathway were obviously reduced in the JTC-801 treated SKOV3 group. This suggests that JTC-801 exerts its anticancer effect through the PI3K/AKT signaling pathway. Our data also highlights the possibility of using JTC-801 as a novel therapeutic drug for OC treatment mean while it plays the analgesic effect.