Abiotic Methane Production Driven by Ubiquitous Non-Fenton-Type Reactive Oxygen Species.

Abiotic CH4 production driven by Fenton-type reactive oxygen species (ROS) has been confirmed to be an indispensable component of the atmospheric CH4 budget. While the chemical reactions independent of Fenton chemistry to ROS are ubiquitous in nature, it remains unknown whether the produced ROS can drive abiotic CH4 production. Here, we first demonstrated the abiotic CH4 production at the soil-water interface under illumination. Leveraging this finding, polymeric carbon nitrides (CNx) as a typical analogue of natural geobattery material and dimethyl sulfoxide (DMSO) as a natural methyl donor were used to unravel the underlying mechanisms. We revealed that the ROS, photocatalytically produced by CNx, can oxidize DMSO into CH4 with a high selectivity of 91.5 %. Such an abiotic CH4 production process was further expanded to various non-Fenton-type reaction systems, such as electrocatalysis, pyrocatalysis and sonocatalysis. This work provides insights into the geochemical cycle of abiotic CH4, and offers a new route to CH4 production via integrated energy development.

Growth of electroautotrophic microorganisms using hydrovoltaic energy through natural water evaporation.

It has been previously shown that devices based on microbial biofilms can generate hydrovoltaic energy from water evaporation. However, the potential of hydrovoltaic energy as an energy source for microbial growth has remained unexplored. Here, we show that the electroautotrophic bacterium Rhodopseudomonas palustris can directly utilize evaporation-induced hydrovoltaic electrons for growth within biofilms through extracellular electron uptake, with a strong reliance on carbon fixation coupled with nitrate reduction. We obtained similar results with two other electroautotrophic bacterial species. Although the energy conversion efficiency for microbial growth based on hydrovoltaic energy is low compared to other processes such as photosynthesis, we hypothesize that hydrovoltaic energy may potentially contribute to microbial survival and growth in energy-limited environments, given the ubiquity of microbial biofilms and water evaporation conditions.

Cribiform and intraductal carcinoma in hereditary prostate cancer: clinical and pathological analysis of 20 cases.

Cribiform and intraductal carcinoma are patterns of aggressive prostate carcinoma. This study investigated the clinical and pathological features of hereditary prostate cancer. Twenty cases of hereditary prostate cancer from 11 family lines treated at the First Affiliated Hospital of Zhejiang University School of Medicine between 2016-2022 were included to summarize the clinical and pathological features by analyzing clinical information including follow up the survival of the patients and pathological features. Of the 20 hereditary prostate cancer cases, 19 were radical prostate specimens and 1 was a biopsy specimen. The mean age at diagnosis of the patients was 67.55 years and the mean PSA was 15.44 ng/ml, of which 10 cases had PSA ≥ 10 ng/ml and 5 cases had PSA ≥ 20 ng/ml. Of the 19 radical prostate specimens, Gleason cribriform pattern (Gleason grade 4) of PCa is observed in 15 cases (78.95%), and intraductal carcinoma, usually a rare form, is seen in 9 cases (47.3%). Two cases demonstrated pelvic lymph node metastasis, and 7 cases (35%) belonged to high-risk or very high-risk PCa. One case (5.26%) showed partial deletion of expression of RB1, and 13 cases (68.42%) showed deletion of expression of PTEN. Follow-up was 4-90 months, 2 cases had biochemical recurrence and 1 case died from prostate cancer. The mean age at diagnosis of this group of patients with hereditary prostate cancer was 67.55 years, the mean preoperative PSA was 15.44 ng/ml, and their histomorphology was characterized by a high percentage of intraductal carcinoma and cribriform pattern of the prostate.

Microbial biofilms for self-powered noncontact sensing.

Noncontact sensing technology plays a vital role in the intelligent human-machine interface, as the essential medium for exchanging information between human and electronic devices. To date, several inorganic materials-based noncontact sensing techniques have been used to accurately detect touch, electrical property, and physical motion. However, limited available materials, dependence on additional power supplies, and poor power production performance, have seriously obstructed the practical applications of noncontact sensing technology. Here, we developed simple self-powered noncontact sensors (SNSs) assembled using a typical G. sulfurreducens biofilm as the core component. In noncontact mode, the sensor demonstrated excellent self-powered sensing performance with maximum voltage output of 10 V and a current of 60 nA, a maximum sensing range of 40 cm which is the farthest reported to date. Depending on its excellent sensing characteristic, the SNSs was used to monitor human breathing in this work. Furthermore, an array of united SNSs was able to localize external electric fields and effectively extend the sensing area by increasing the number of devices. Compared to traditional inorganic materials, microbial biofilms have the advantages of wide existence, self-proliferation, low cost, environmental friendliness, and ultra-fast self-healing property (seconds level). The proposed biofilm SNSs in our work provides new insights for noncontact power generation of biomaterials and self-driven sensing.

Methanogenesis in the presence of oxygenic photosynthetic bacteria may contribute to global methane cycle.

Accumulating evidences are challenging the paradigm that methane in surface water primarily stems from the anaerobic transformation of organic matters. Yet, the contribution of oxygenic photosynthetic bacteria, a dominant species in surface water, to methane production remains unclear. Here we show methanogenesis triggered by the interaction between oxygenic photosynthetic bacteria and anaerobic methanogenic archaea. By introducing cyanobacterium Synechocystis PCC6803 and methanogenic archaea Methanosarcina barkeri with the redox cycling of iron, CH4 production was induced in coculture biofilms through both syntrophic methanogenesis (under anoxic conditions in darkness) and abiotic methanogenesis (under oxic conditions in illumination) during the periodic dark-light cycles. We have further demonstrated CH4 production by other model oxygenic photosynthetic bacteria from various phyla, in conjunction with different anaerobic methanogenic archaea exhibiting diverse energy conservation modes, as well as various common Fe-species. These findings have revealed an unexpected link between oxygenic photosynthesis and methanogenesis and would advance our understanding of photosynthetic bacteria's ecological role in the global CH4 cycle. Such light-driven methanogenesis may be widely present in nature.

A comparative study on antioxidant activity of different parts of lotus (Nelumbo nuficera Gaertn) rhizome

Abstract In this study, the antioxidant activities of different parts of lotus (Nelumbo nuficera Gaertn) rhizome were compared. The total phenolic content of lotus rhizome was determined, and Ferric reducing antioxidant power (FRAP) assay, 1,1-diphenyl-2-picrylhydrazyl hydrate (DPPH) radical-scavenging assay and β-carotene-linoleic acid assay were performed to assess the antioxidant activity of lotus rhizome. Results showed that there was a significant difference in total phenolic content and antioxidant activity between any two of four parts of lotus rhizome. The order of total phenolic content and antioxidant activity in different parts of lotus rhizome was as follows: peel of old lotus rhizome > peel of young lotus rhizome > flesh of old lotus rhizome > flesh of young lotus rhizome. The total phenol content is significantly positive correlated with the antioxidant activity in different parts of lotus rhizome. This study has provided a basis for further exploring the antioxidant components in lotus rhizome.