Effects of varying amounts of different biochars on mercury methylation in paddy soils and methylmercury accumulation in rice (Oryza sativa L.).

There is growing evidence for the potential of biochars (BCs) in remediating mercury-contaminated paddy soils, but the high doses commonly used in laboratory studies discourage BC application in practice. To address these difficulties, we compared the effects of varying amounts of BCs from different sources on the formation of methylmercury (MeHg) in soil and its accumulation in rice through microcosm and pot experiments. The addition of a wide range of added doses (0.3, 0.6, 1, 2, 4 and 5 %, w/w) of BCs derived from different biomass feedstocks (i.e., corn stalk, wheat straw, bamboo, oak and poplar) significantly decreased the fraction of ammonium thiosulfate ((NH4)2S2O3)-extractable MeHg in the soil, although the MeHg contents varied with BC types and doses during soil incubation. However, the extractable MeHg in the soil did not continuously decrease with increasing BC doses, especially at doses of >1 %, resulting in limited further reductions. Moreover, a relatively low application rate (0.3-0.6 %, w/w) of BCs (i.e., corn stalk, wheat straw and bamboo-derived BC), especially of bamboo-derived BCs, significantly decreased the MeHg levels (42-76 %) in rice grains (brown rice). Meanwhile, the extractable soil MeHg decreased (57-85 %), although the MeHg in the soil varied under BC amendment during rice cultivation. These results provide further evidence that applying BC produced from different raw carbon materials (e.g., lignocellulosic biomass) could effectively reduce MeHg accumulation in rice grains, possibly due to MeHg bioavailability reduction in the soil. Our results suggest the possibility of mitigating MeHg accumulation in rice with a low dose of BCs, with great potential for use in remediating moderately contaminated paddy soils.

C1q/TNF-related protein 3 alleviates heart failure via attenuation of oxidative stress in myocardial infarction rats.

C1q-tumor necrosis factor-related protein 3 (CTRP3), an adipokine, has been reported to be closely related to cardiovascular diseases (CVDs). However, the effect of CTRP3 on heart failure (HF) remains dimness. This study was to explore the role of CTRP3 in HF and its potential interaction mechanism. Heart failure model was established by inducing ischemia myocardial infarction (MI) through ligation of the left anterior descending artery in Sprague-Dawley rats. Four weeks later, the rats were detected by transthoracic echocardiography and masson staining. Atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), cardiac troponin I (cTnI) levels, creatine kinase-MB (CK-MB) and oxidative stress levels were recorded. The level of CTRP3 was reduced in the cardiomyocytes (CMs) treated with oxygen-glucose deprivation (OGD) and in the heart of MI rats. CTRP3 overexpression alleviated cardiac dysfunction, attenuated the cardiac fibrosis, and inhibited the increases of ANP, BNP, cTnI and CK-MB in the serum of MI rats. The increases of ANP and BNP in the CMs, and the collagen I and collagen III in the cardiac fibroblasts (CFs) induced by OGD were inhibited by CTRP3 overexpression. The enhancement of oxidative stress in the heart of MI rats was inhibited by CTRP3 overexpression. These results indicated that overexpression of CTRP3 could improve cardiac function and the related cardiac fibrosis in MI-induced HF rats via inhibition of oxidative stress. Upregulation of CTRP3 may be a strategy for HF therapy in the future.

Foxo3a-Mediated DNMT3B Impedes Cervical Cancer Cell Proliferation and Migration Capacities through Suppressing PTEN Promoter Methylation.

OBJECTIVE: Cervical cancer is linked with the constitutive activation of growth factors and gene mutations-induced pro-survival signaling pathways. Herein, we purposed to explore the possible molecular mechanism of Foxo3a-mediated DNMT3B in the proliferation and migration of cervical cancer cells via mediating the PTEN promoter methylation. METHODS: Foxo3a expression in cervical cancer was tested by qRT-PCR and western blot experiments. The cervical cancer cell biological functions with overexpression of Foxo3a were evaluated by CCK-8 assay, Transwell experiment, and flow cytometry, respectively. MS-PCR was utilized for testing the PTEN methylation levels, and ChIP experiment was implemented for evaluating the enrichment of DNMT3B in the PTEN promoter region and the binding of Foxo3a and DNMT3B. The PTEN methylation and interference with Foxo3a expression were performed in cervical cancer cells, and then their impacts on cervical cancer cell biological functions were observed. RESULTS: FOXO3a was expressed at a low level in cervical cancer, and its overexpression contributed to a reduction in cell proliferative, migratory and invasive capabilities, and an elevation in apoptosis rate. Foxo3a blocked its methylation with the PTEN promoter by repressing DNMT3B activity. Upon treatment with methyltransferase inhibitor (5-aza-dc), the malignant phenotypes of cervical cancer cells were diminished. 5-aza-dc neutralized the impacts of silencing Foxo3a on malignant phenotypes. CONCLUSION: This research underlines that Foxo3a blocks its methylation with the PTEN promoter by inhibiting DNMT3B activity, which subsequently impedes cervical cancer cell progression.

Establishment and validation of a risk prediction model for high-grade cervical lesions.

OBJECTIVE: To establish and validate a risk prediction model for cervical high-grade squamous intraepithelial lesions (HSIL). METHODS: This retrospective study included patients who underwent cervical biopsies at the Cervical Disease Centre of Maternal and Child Hospital of Hubei Province between January 2021 and December 2021. RESULTS: A total of 1630 patients were divided into the HSIL + cervical lesion group (n = 186) and the ≤ LSIL cervical lesions group (n = 1444). LSIL, ASC-H, HSIL and SCC, high-risk HPV, HPV16, HPV18/45, multiple HPV strains, acetowhite epithelium, atypical vessels, and mosaicity were independently associated with HSIL + lesions. These factors were used to establish a risk prediction model with a demonstrated area under the curve (AUC) of 0.851 and a C-index of 0.829. Calibration curve analysis showed that the model performed well, with a mean absolute error (MAE) of 0.005. The decision curve showed that the model created by combining the risk factors was more specific and sensitive than each predictive variable. CONCLUSION: The model for predicting HSIL demonstrated promising predictive capability and might help identify patients requiring biopsy and treatment.

A short peptide encoded by long non-coding RNA small nucleolar RNA host gene 6 promotes cell migration and epithelial-mesenchymal transition by activating transforming growth factor-beta/SMAD signaling pathway in human endometrial cells.

BACKGROUND: Endometrial dysfunction is closely correlated with the development of multiple severe gynecological disorders including intrauterine adhesion. Accumulating evidence supports that some long non-coding RNAs (lncRNAs) have peptide-coding potential. In this text, the peptide-coding ability of lncRNA SNHG6 was examined. Also, the effects of an SNHG6-encoded peptide on the viability and migration of human endometrial stromal cells (hESCs) and human endometrial epithelial cells (hEECs) and related molecular mechanisms were explored. METHODS: The peptide-encoding potential of SNHG6 was predicted by FuncPEP and getorf databases and validated by western blot assay. Cell viability was tested by cell counting kit-8 assay. Cell migratory ability was examined by wound healing and transwell migration assays. Protein levels of genes were measured by western blot assay. RESULTS: Prediction analysis suggested that SNHG6 had the potential peptide-coding ability and multiple open-reading frames (ORFs). Western blot validated that SNHG6 ORF#1 and ORF#2 could translate into short peptides. SNHG6 ORF#2 overexpression facilitated cell migration and epithelial-mesenchymal transition (EMT) in hESCs and hEECs, while these effects were abrogated by transforming growth factor-beta (TGF-ß)/SMAD signaling inhibitor GW788388. Moreover, GW788388 inhibited the increase of p-SMAD2 and p-SMAD3 levels induced by SNHG6 ORF#2 in hESCs. SNHG6 ORF#2-encoded peptide did not influence endometrial stromal and epithelial cell viability. CONCLUSIONS: LncRNA SNHG6 ORF#1 and ORF#2 could translate into small peptides and SNHG6 ORF#2 overexpression promoted cell migration and EMT by activating the TGF-ß/SMAD pathway in hESCs and hEECs, suggesting the potential roles of SNHG6-encoded peptides in the development of endometrial stromal and epithelial cells and related gynecological diseases.

Controllable generation of interfacial gas structures on the graphite surface by substrate hydrophobicity and gas oversaturation in water.

Spherical nanobubbles and flat micropancakes are two typical states of gas aggregation on solid-liquid surfaces. Micropancakes, which are quasi-two-dimensional gaseous structures, are often produced accompanied by surface nanobubbles. Compared with surface nanobubbles, the intrinsic properties of micropancakes are barely understood due to the challenge of the highly efficient preparation and characterization of such structures. The hydrophobicity of the substrate and gas saturation of solvents are two crucial factors for the nucleation and stability of interfacial gas domains. Herein, we investigated the synergistic effect of the surface hydrophobicity and gas saturation on the generation of interfacial gas structures. Different surface hydrophobicities were achieved by the aging process of highly oriented pyrolytic graphite (HOPG). The results indicated that higher surface hydrophobicity and gas oversaturation could create surface nanobubbles and micropancakes with higher efficiency. Strong surface hydrophobicity could promote nanobubble nucleation and higher gas saturation would induce bigger nanobubbles. Degassed experiments could remove most of these structures and prove that they are actually gaseous domains. Finally, we draw a region diagram to describe the formation conditions of nanobubbles, micropancakes based on observations. These results would be very helpful for further understanding the formation of interfacial gas structures on the hydrophobic surface under different gas saturation.

Low oxygen levels with high redox heterogeneity in the late Ediacaran shallow ocean: Constraints from I/(Ca + Mg) and Ce/Ce* of the Dengying Formation, South China.

Most previous studies focused on the redox state of the deep water, leading to an incomplete understanding of the spatiotemporal evolution of the redox-stratified ocean during the Ediacaran-Cambrian transition. In order to decode the redox condition of shallow marine environments during the late Ediacaran, this study presents I/(Ca + Mg), carbon and oxygen isotope, major, trace, and rare earth element data of subtidal to peritidal dolomite from the Dengying Formation at Yangba, South China. In combination with the reported radiometric and biostratigraphic data, the Dengying Formation and coeval successions worldwide are subdivided into a positive δ¹³ C excursion (up to ~6‰) in the lower part (~551-547 Ma) and a stable δ¹³ C plateau (generally between 0‰ and 3‰) in the middle-upper part (~547-541 Ma). The overall low I/(Ca + Mg) ratios (<0.5 µmol/mol) and slightly negative to no Ce anomalies (0.80 < [Ce/Ce*]_SN < 1.25), point to low-oxygen levels in shallow marine environments at Yangba. Moreover, four pulsed negative excursions in (Ce/Ce*)_SN (between 0.62 and 0.8) and the associated two positive excursions in I/(Ca + Mg) ratios (up to 2.02 µmol/mol) are observed, indicative of weak oxygenations in the shallow marine environments. The comparison with other upper Ediacaran shallow water successions worldwide reveals that the (Ce/Ce*)_SN and I/(Ca + Mg) values generally fall in the Precambrian range but their temporal trends differ among these successions (e.g., Ce anomaly profiles significantly different between Yangba and the Yangtze Gorge sections), which point to low oxygen levels with high redox heterogeneity in the surface ocean. This is consistent with the widespread anoxia as revealed by low δ²³⁸ U values reported by previous studies. Thus, the atmospheric oxygen concentrations during the late Ediacaran are estimated to be very low, similar to the case during the most Mesoproterozoic to early Neoproterozoic period.

Detection of mild cognitive impairment in type 2 diabetes mellitus based on machine learning using privileged information.

Type 2 diabetes mellitus (T2DM) patients may develop into mild cognitive impairment (MCI) or even dementia. However, there is lack of reliable machine learning model for detection MCI in T2DM patients based on machine learning method. In addition, the brain network changes associated with MCI have not been studied. The aim of this study is to develop a machine learning based algorithm to help detect MCI in T2DM. There are 164 participants were included in this study. They were divided into T2DM-MCI (n = 56), T2DM-nonMCI (n = 49), and normal controls (n = 59) according to the neuropsychological evaluation. Functional connectivity of each participant was constructed based on resting-state magnetic resonance imaging (rs-fMRI). Feature selection was used to reduce the feature dimension. Then the selected features were set into the cascaded multi-column random vector functional link network (RVFL) classifier model using privileged information. Finally, the optimal model was trained and the classification performance was obtained using the testing data. The results show that the proposed algorithm has outstanding performance compared with classic methods. The classification accuracy of 73.18 % (T2DM-MCI vs NC) and 79.42 % (T2DM-MCI vs T2DM-nonMCI) were achieved. The functional connectivity related to T2DM-MCI mainly distribute in the frontal lobe, temporal lobe, and central region (motor cortex), which could be used as neuroimaging biomarkers to recognize MCI in T2DM patients. This study provides a machine learning model for diagnosis of MCI in T2DM patients and has potential clinical significance for timely intervention and treatment to delay the development of MCI.

OTX1 promotes tumorigenesis and progression of cervical cancer by regulating the Wnt signaling pathway.

Cervical cancer is a common malignant tumor in females. Orthodenticle homolog 1 (OTX1) serves a key role in the occurrence and progression of tumors. The present study aimed to investigate the role and potential mechanism of OTX1 in cervical cancer. OTX1 expression was analyzed by western blotting, reverse transcription­quantitative PCR and immunohistochemistry. MTT assay was performed to assess cell viability. EdU and colony formation assay were used to measure cell proliferation. Wound healing and Transwell assays were performed to measure cell migration and invasion. Western blot assay was performed for the assessment of protein expression. Gene set enrichment analysis (GSEA) was performed to analyze signaling pathways regulated by OTX1. Co­Immunoprecipitation assay was performed to confirm the interaction between OTX1 and Wnt9b. In cervical cancer tissue and cells, OTX1 was significantly upregulated. OTX1 overexpression promoted proliferation, migration and invasion of cervical cancer cells. OTX1 silencing significantly decreased cell proliferation, migration and invasion of cervical cancer. GSEA showed that OTX1 activated the Wnt signaling pathway. OTX1 silencing inhibited the increased levels of adenomatous polyposis coli (APC), glycogen synthase kinase (GSK)­3ß and axis inhibition protein (AXIN)2 and decreased levels of Wnt9b and ß­catenin. OTX1 overexpression decreased the levels of APC, GSK­3ß and AXIN2 and increased levels of Wnt9b and ß­catenin. However, XAV939 (a Wnt signaling inhibitor) and ß­catenin silencing partly eliminated the effect of OTX1 overexpression on cervical cancer cells. OTX1 promoted the progression of cervical cancer by activating the Wnt signaling pathway.

Effects of a fixed nurse team in the orthopaedic surgery operating room on work efficiency and patient outcomes: a propensity score-matched historically controlled study.

BACKGROUND: The work value of operating room (OR) nurses is directly reflected in nursing quality. However, evaluating the work value of these nurses has not been sufficiently investigated. This study evaluated the effects of a fixed nurse team (FNT) in an orthopaedic surgery OR on work efficiency and patient outcomes. METHODS: A propensity score-matched historically controlled study conducted from 1 July 2015 to 30 June 2018 was used to investigate the difference in nursing quality between an FNT period and a non-FNT period in the orthopaedic surgery OR at a tertiary care hospital in China. The primary outcome was surgical site infections (SSIs) during in-hospital visits, and as a secondary outcome, other nursing-sensitive quality indicators were assessed with historically controlled data. A multifactor logistic regression model was constructed to examine the primary outcome differences between the FNT and non-FNT periods before and after propensity score matching. RESULTS: In total, 5365 patients and 33 nurses were included in the final analysis. The overall SSI rate was 2.1% (110/5365; the non-FNT period 2.6% [64/2474], the FNT period 1.6% [46/2891]). A lower incidence of SSIs in patients (odds ratio 0.57, 95% CI 0.36 to 0.88, P=0.013), a lower turnover time of the surgical procedure (odds ratio 0.653, 95% CI 0.505 to 0.844, P<0.001), and improvement in surgeon satisfaction (odds ratio 1.543, 95% CI 1.039 to 2.292, P=0.031), were associated with the FNT period compared with the non-FNT period. However, we did not find significant differences between the FNT period and the non-FNT period in terms of the other indicators. CONCLUSIONS: The presence of an FNT in an OR reduces the incidence of SSIs in surgical patients and the turnover time of surgical procedures and improves surgeon satisfaction. Further implementation of an advanced-practice nurse model with nurse specialists is encouraged.

Mineralogical Properties of a Refractory Tantalum-Niobium Slag and the Effect of Roasting on the Leaching of Uranium-Thorium.

In order to realize sustainable development, it is beneficial to explore an appropriate process to recover the radionuclides contained in tantalum-niobium slag. By micro-mineralogical analysis and roasting experiments, the effect of uranium-thorium leaching from a refractory tantalum-niobium slag is investigated. The uranium and thorium content in the slag is 2.26 × 103 mg/kg and 7.84 × 103 mg/kg, which have large recovery value. As the surface area and pore size of the slag are very small, the leaching agent cannot fully penetrate the particles. Various methods of characterization are used to analyze the mineralogical properties of roasted slag at different temperatures. The leaching ratio of U-Th is 90.84% and 96.62% at the optimum roasting temperature of 500 °C, which are about 39% and 27% higher than original samples. The oxidants Fe3+, O2 and Mn can also promote the conversion of insoluble U(IV) to soluble U(VI). Roasting reduces the content of organic C and S, thereby preventing reduction of U(VI), and increasing pore size as well as specific surface area also promote radionuclide leaching. Thus, the roasting method at 500 °C can destroy the surface wrapping structure of radionuclides, reduce the internal density of minerals, and improve uranium-thorium leaching ratio significantly. It is of great practical significance to reduce the radioactive hazard of waste tantalum-niobium slag and to strengthen the sustainable utilization of resources by suitable process improvement techniques.

Forensic Analysis and Genetic Structure Construction of Chinese Chongming Island Han Based on Y Chromosome STRs and SNPs.

Y-chromosome short tandem repeat (Y-STR) and Y-chromosome single nucleotide polymorphism (Y-SNP) are genetic markers on the male Y chromosome for individual identification, forensic applications, and paternal genetic history analysis. In this study we successfully genotyped 38 Y-STR loci and 24 Y-SNP loci of Pudong Han (n = 689) and Chongming Han (n = 530) in Shanghai. The haplotype diversity of the Y filer platinum genotyping system was the highest in the Han population in the Pudong area of Shanghai (0.99996) and Chongming Island (0.99997). The proportion of unique haplotypes was 97.10% (Pudong) and 98.49% (Chongming), respectively. The multidimensional scaling analysis and phylogenetic analysis were performed according to the genetic distance Rst, which was calculated based on the Y-STR gene frequency data. Moreover, we made a comparison on the frequency distribution analysis and principal component analysis of haplogroups in both populations. As a result, Shanghai Pudong Han, Chongming Island Han, and Jiangsu Han were determined to have a strong genetic affinity. The haplogroup distribution characteristics of the Pudong Han and Chongming Han populations were similar to those of the southern Han population. The results of haplotype network analysis showed that Jiangsu Wujiang Han and Jiangsu Changshu Han had more paternal genetic contributions to the formation of Shanghai Pudong Han and Chongming Island Han. Through the joint analysis of SNPs and STRs, this study deeply analyzed the paternal genetic structure of the Pudong Han and Chongming Han populations. The addition of Y-SNP haplogroups to forensic applications can provide information for pedigree investigation.

Comonomer-Tuned Gel Electrolyte Enables Ultralong Cycle Life of Solid-State Lithium Metal Batteries.

Rechargeable lithium metal batteries (LMBs) are considered the "holy grail" of energy storage systems. Unfortunately, uncontrollable dendritic lithium growth inherent in these batteries has prevented their practical applications. The benefits of solid-state electrolyte for LMBs are limited due to the common compromise between ionic conductivity and mechanical property. This work proposes a mechanism for simultaneous improvement in ionic conductivity and mechanical strength of gel polymer electrolyte (GPE) which is based on tunable cross-linked polymer network through adjusting monomer ratios. With increasing bisphenol A ethoxylate dimethacrylate (E2BADMA) and poly(ethylene glycol) diacrylate (PEGDA) mass ratios in GPE precursors, the formed polymer network experienced a composition evolution from a 3D cross-linked mono PEGDA network to triple PEGDA, E2BADMA, and PEGDA/E2BADMA networks and then to dual E2BADMA and PEGDA/E2BADMA networks, accompanied by the increase in both storage modulus (from 6 to 37 MPa) and ionic conductivity (from 0.06 to 0.44 mS cm-1). As a result, the E2BADMA/PEGDA mass ratio of 2:1 facilitates the successful fabrication of a dual-network-supported GPE (PEEPL-12) with a mechanical strength of 37 MPa and superior electrochemical properties (a high ionic conductivity of 0.44 mS cm-1 and a wide electrochemical stability window of 4.85 V vs Li/Li+). Such polymer electrolyte-based symmetric lithium metal batteries delivered a long cycle life (2000 h at 0.1 mA cm-2 and 0.1 mAh cm-2), and the Li|PEEPL-12|LiFePO4 cell delivered a high capacity of 140 mAh g-1 at the 100th cycle at the current density of 0.1 C (1 C = 170 mAh g-1). A more thorough investigation indicated the formation of a stable solid electrolyte interphase layer on a lithium metal anode. These extraordinary features open up a venue for fabrication of advanced polymer electrolyte for long-cycle-life lithium metal batteries.

Wood-Derived Monolithic Catalysts with the Ability of Activating Water Molecules for Oxygen Electrocatalysis.

Oxygen reduction reaction (ORR) is the key reaction on cathode of rechargeable zinc-air batteries (ZABs). However, the lack of protons in alkaline conditions limits the rate of ORR. Herein, an activating water strategy is proposed to promote oxygen electrocatalytic activity by enhancing the proton production from water dissociation. FeP nanoparticles (NPs) are coupled on N-doped wood-derived catalytically active carbon (FeP-NWCC) to associate bifunctional active sites. In alkaline, FeP-NWCC possesses outstanding catalytic activities toward ORR (E1/2  = 0.86 V) and Oxygen evolution reaction (OER) (overpotential is 310 mV at 10 mA cm-2 ). The liquid ZABs assembled by FeP-NWCC deliver superior peak power density (144 mW cm-2 ) and cycle stability (over 450 h). The quasi-solid-state ZABs based on FeP-NWCC also display excellent performances. Theoretical calculation illustrates that the superb bifunctional performance of FeP-NWCC results from the elevated dissociation efficiency of water via FeP NPs to assist the oxygen catalytic process. The strategy of activating water provides a new perspective for the design of ORR/OER bifunctional catalysts. This work is a model for the application of forest biomass.

Polyethyleneimine incorporated chitosan/α-MnO2 nanorod honeycomb-like composite foams with remarkable elasticity and ultralight property for the effective removal of U(VI) from aqueous solution.

The development of new adsorbents is needed to address the environmental challenges of radioactive wastewater treatment. Herein we reported a novel polyethyleneimine incorporated chitosan/α-MnO2 nanorod honeycomb-like composite (PCM) foam with remarkable elasticity and ultralight property for U(VI) removal. Among different PCM sorbents, PCM-40 possessed the highest sorption capacity for U(VI) due to its highly developed macroporous structure and high content of amine/imine groups. The kinetics were well-simulated by the pseudo-second-order model, indicating chemisorption as the rate-controlling step. The isotherms could be described by the Langmuir model, suggesting mono-layer homogeneous sorption of U(VI). The maximum sorption U(VI) capacity for PCM-40 reaches up to 301.9 mg/g at pH 4.5 and 298 K. The thermodynamic parameters revealed the spontaneous and endothermic nature of the adsorption process. The main sorption mechanism is related to the complexation of uranyl ions with the amine/imine and hydroxyl groups. The high sorption capacity, fast kinetic rate and relatively good selectivity of PCM-40 highlights its promising application in radioactive pollution cleanup.

Microenvironment Engineering for the Electrocatalytic CO2 Reduction Reaction.

Rather than just focusing on the catalyst itself in the electrocatalytic CO2 reduction reaction (eCO2 RR), as previously reviewed elsewhere, we herein extend the discussion to the special topic of the microenvironment around the electrocatalytic center and present a comprehensive overview of recent research progress. We categorize the microenvironment based on the components relevant to electrocatalytic active sites, i.e., the catalyst surface, substrate, co-reactants, electrolyte, membrane, and reactor. Supported by most of the reported articles, the relevant factors affecting the catalytic performance of eCO2 RR are then discussed in detail, and existing challenges and potential solutions are mentioned. Perspectives for the future research on eCO2 RR, including the integration of different microenvironment factors, the extension to industrial application by coupling with carbon capture and conversion, and separation of products, are also discussed.

Formation of Bulk Nanobubbles Induced by Accelerated Electrons Irradiation: Dependences on Dose Rates and Doses of Irradiation.

Radiation on aqueous solutions can induce water radiolysis with products of radicals, H2, H2O2, and so on, and their consequent biological effects have long been interested in radiation chemistry. Unlike the decomposition of water by electric current that produces a significant number of bubbles, the gas products from the radiolysis of water are normally invisible by bare eyes, little is known on whether nanosized bubbles can be produced and what their dynamics are upon irradiation. Here, we first presented the formation of nanoscale bulk bubbles by irradiating pure water with accelerated electrons and their concentration and size distribution changes with the dose and rate of irradiation. The nanoparticle tracking analysis showed that irradiation can actually produce a certain amount of bulk nanobubbles in pure water. They exhibited a dependence on the irradiation dose rates and irradiation doses. The results indicated that the concentration of formed bulk nanobubbles increased as the irradiation dose rates increased, but it will increase and then decrease with the increased irradiation doses. The formed bulk nanobubbles could maintain stability for several hours. Our findings will provide a new angle of view for the radiation chemistry of water, and the formed nanobubbles may help elucidate the biological effects of irradiated solutions.

Coupling Fe3 C Nanoparticles and N-Doping on Wood-Derived Carbon to Construct Reversible Cathode for Zn-Air Batteries.

Electrochemical reduction of oxygen plays a critical role in emerging electrochemical energy technologies. Multiple electron transfer processes, involving adsorption and activation of O2 and generation of protons from water molecules, cause the sluggish kinetics of the oxygen reduction reaction (ORR). Herein, a double-active-site catalyst of Fe3 C nanoparticles coupled to paulownia wood-derived N-doped carbon (Fe3 C@NPW) is fabricated via an active-site-uniting strategy. One site on Fe3 C nanoparticles contributes to activating water molecules, while another site on N-doped carbon is responsible for activating oxygen molecules. Benefiting from the synergistic effect of double active sites, Fe3 C@NPW delivers a remarkable catalytic activity for ORR with a half-wave potential of 0.87 V (vs. RHE) in alkaline electrolyte, outperforming commercial Pt/C catalyst. Moreover, zinc-air batteries (ZABs) assembled with Fe3 C@NPW as a catalyst on cathode achieve a large specific capacity of 804.4 mA h gZn-1 and a long-term stability of 780 cycles. The model solid-state ZABs also display satisfactory performances with an open-circuit voltage of 1.39 V and a high peak power density of 78 mW cm-2 . These outstanding performances reach the level of first-rank among the non-noble metal electrode materials. This work offers a promising approach to creating double-active-site catalysts by the active-site-uniting strategy for energy conversion fields.

Evaluating the survival of Aspergillus niger in a highly polluted red soil with addition of Phosphogypsum and bioorganic fertilizer.

Phosphate-solubilizing fungi (PSF) can enhance P release from phosphate minerals to immobilize heavy metals. However, this promotion substantially depends on their survival in highly polluted soils. The aim of this study was to investigate the survival of PSF after addition of phosphogypsum (PG) and bioorganic fertilizer (BF) in the soil with coexistence of multiple heavy metals, e.g., Pb, As, Cd, Sb, etc. Addition of typical PSF (Aspergillus niger) did not promote the formation of pyromorphite (the most stable form of Pb), possibly due to the buffering effect of the soil (the secreted oxalic acid was neutralized) and limited P supply. Meanwhile, despite that A. niger has high tolerance to heavy metal stress, its survival was significantly declined due to the deficiency of available P. It was also shown that PG, as the major by-product in phoschemical industry, still has relatively high available P compared with common natural soils. PG addition dramatically increased available P (up to 93.87 mg/kg) and the subsequent fungal growth. However, sole PG did not promote the formation of pyromorphite, probably as the abundant Fe2+ and Mn2+ prevented the contact between PO43- and Pb2+ in the soil system. The enhanced soil respiration after addition of BF and PG confirmed the promoted microbial activity (elevated to 3465.58 µg C kg h-1). This study showed PG's potential as P source for both microbial growth and heavy metal remediation in soil system. A combination of PG, A. niger, and BF can hence achieve long-term bioremediation of heavy metals.